Sound Practices Mailing List Files - Volume 2
=========================================================================
From: "Jim Charron" <jimpcn@sympatico.ca>
Subject: [JN] R76 listening impressions, questions, and new amp topology: 76->71A->6B4G
Date: Sat, 18 Aug 2001 07:57:49 -0400
Source: Sound Digest Archive v02.n949
Joes;
Problem with all this tube tasting; is that it's a waist of time and
money.
I wish this list and others would RATE their projects and/or compare them
to others with opinions.
I would think most are trying to put systems together that we can listen to
music with and just enjoy.
Not everyone is rich/ retired.
Most have jobs and families.
Ya, there are alot of projects to build, just going sideways. What's the
point.
Waisting time and never moving a step up.
Sounds frustrating, because it is.
Right now I'm using a vintage prodction piece that I've not heard better;
It's an electrohome VA-200S.
Sounds like a joke but it's not. Even has a great phono section.
Before I waist my time/money and build another piece, it will have to blow
away this Electrohome, hohoho.
I know alot of you have experiences and knowledge about great designs and
wish they were shared.
and wished they were shared, and wish they were shared!!!
Latter, Jim.
> > compared to my 5687 based. The 76 are a little noisy too.
> >
> > Should I try 6SN7 or 6J5 instead?
>
> Of course. Welcome to the world of tube tasting.
>
> JL
>
>
=========================================================================
From: TubeGarden@aol.com
Subject: Re: [JN] R76 listening impressions, questions, and new amp topology: 76->71A...
Date: Sat, 18 Aug 2001 08:09:14 EDT
Source: Sound Digest Archive v02.n949
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Greets!
The problem with all you neo-nerds who have no time for instant gratification
is you waste our time with your endless whining :)
Happy Ears!
Al B^}
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<HTML><FONT FACE=arial,helvetica><BODY BGCOLOR="#ffffff"><FONT SIZE=2>Greets!
<BR>
<BR>The problem with all you neo-nerds who have no time for instant gratification
<BR>is you waste our time with your endless whining :)
<BR>
<BR>Happy Ears!
<BR>Al B^}
<BR>
<BR></FONT></HTML>
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=========================================================================
From: "John Levreault" <jlevro@mediaone.net>
Subject: Re: [JN] R76 listening impressions, questions, and new amp topology: 76->71A->6B4G
Date: Sat, 18 Aug 2001 10:13:24 -0400
Source: Sound Digest Archive v02.n949
The sad fact is, Jim, just like with wine, women, and song, that there is no
one right way for everyone. I sincerely hope that some day you will find the
time to embark upon the journey of audio experimentation. In the mean time,
I wish you well with your VA-200S.
JL
- ----- Original Message -----
From: "Jim Charron" <jimpcn@sympatico.ca>
To: "John Levreault" <jlevro@mediaone.net>; <rcjones1@mmm.com>;
<sound@lists.io.com>
Sent: Saturday, August 18, 2001 7:57 AM
Subject: [JN] R76 listening impressions, questions, and new amp topology:
76->71A->6B4G
> Joes;
>
> Problem with all this tube tasting; is that it's a waist of time and
> money.
>
>
> I wish this list and others would RATE their projects and/or compare
them
> to others with opinions.
>
> I would think most are trying to put systems together that we can listen
to
> music with and just enjoy.
> Not everyone is rich/ retired.
> Most have jobs and families.
>
> Ya, there are alot of projects to build, just going sideways. What's the
> point.
> Waisting time and never moving a step up.
> Sounds frustrating, because it is.
>
> Right now I'm using a vintage prodction piece that I've not heard better;
> It's an electrohome VA-200S.
> Sounds like a joke but it's not. Even has a great phono section.
>
> Before I waist my time/money and build another piece, it will have to blow
> away this Electrohome, hohoho.
>
>
> I know alot of you have experiences and knowledge about great designs and
> wish they were shared.
> and wished they were shared, and wish they were shared!!!
>
> Latter, Jim.
>
>
>
>
>
> > > compared to my 5687 based. The 76 are a little noisy too.
> > >
> > > Should I try 6SN7 or 6J5 instead?
> >
> > Of course. Welcome to the world of tube tasting.
> >
> > JL
> >
> >
>
=========================================================================
From: "Jim Charron" <jimpcn@sympatico.ca>
Subject: [JN] R76 listening impressions, questions, and new amp topology: 76->71A->6B4G
Date: Sat, 18 Aug 2001 13:07:24 -0400
Source: Sound Digest Archive v02.n949
> The sad fact is, Jim, just like with wine, women, and song, that there is
no
> one right way for everyone.
That's true to a point; but clearly these projects,units, etc.. and be
catagorized like
average, better, best. that idea. It would be fun.
I sincerely hope that some day you will find the
> time to embark upon the journey of audio experimentation.
I have , its not years but a life time.
In the mean time,
> I wish you well with your VA-200S.
>
Thanks, sounds great with the lowthers.
Regards Jim.
> > Joes;
> >
> > Problem with all this tube tasting; is that it's a waist of time and
> > money.
> >
> >
> > I wish this list and others would RATE their projects and/or compare
> them
> > to others with opinions.
> >
> > I would think most are trying to put systems together that we can listen
> to
> > music with and just enjoy.
> > Not everyone is rich/ retired.
> > Most have jobs and families.
> >
> > Ya, there are alot of projects to build, just going sideways. What's
the
> > point.
> > Waisting time and never moving a step up.
> > Sounds frustrating, because it is.
> >
> > Right now I'm using a vintage prodction piece that I've not heard
better;
> > It's an electrohome VA-200S.
> > Sounds like a joke but it's not. Even has a great phono section.
> >
> > Before I waist my time/money and build another piece, it will have to
blow
> > away this Electrohome, hohoho.
> >
> >
> > I know alot of you have experiences and knowledge about great designs
and
> > wish they were shared.
> > and wished they were shared, and wish they were shared!!!
> >
> > Latter, Jim.
> >
> >
> >
> >
> >
> > > > compared to my 5687 based. The 76 are a little noisy too.
> > > >
> > > > Should I try 6SN7 or 6J5 instead?
> > >
> > > Of course. Welcome to the world of tube tasting.
> > >
> > > JL
> > >
> > >
> >
>
>
=========================================================================
From: "Jim Charron" <jimpcn@sympatico.ca>
Subject: [JN] R76 listening impressions, questions, and new amp topology: 76->71A...
Date: Sat, 18 Aug 2001 13:17:24 -0400
Source: Sound Digest Archive v02.n949
This is a multi-part message in MIME format.
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You mean, nero-nerds who want instant gratification.
Sorry for the offense.
I think these triode festivals and clubs like bottlehead's mag. ; =
do alot and help to push the envolpe,
by being innovative and comparing equipment.
and not cop-out, by saying welcome to tube tasting.
The experimenter who started this string, is asking for help as not to =
waist time and money.
Latter, catching tunes.
Greets!=20
The problem with all you neo-nerds who have no time for instant =
gratification=20
is you waste our time with your endless whining :)=20
Happy Ears!=20
Al B^}=20
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charset="iso-8859-1"
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<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML><HEAD>
<META http-equiv=3DContent-Type content=3D"text/html; =
charset=3Diso-8859-1">
<META content=3D"MSHTML 5.50.4522.1800" name=3DGENERATOR>
<STYLE></STYLE>
</HEAD>
<BODY bgColor=3D#ffffff>
<DIV><FONT face=3DArial size=3D2>You mean, nero-nerds who =
want instant=20
gratification.</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
<DIV><FONT face=3DArial size=3D2>Sorry for the offense.</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
<DIV><FONT face=3DArial size=3D2>I think these triode=20
festivals and clubs like bottlehead's mag. ; do =
alot and=20
help to push the envolpe,</FONT></DIV>
<DIV><FONT face=3DArial size=3D2>by being innovative and comparing=20
equipment.</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
<DIV><FONT face=3DArial size=3D2>and not cop-out, by saying welcome to =
tube=20
tasting.</FONT></DIV>
<DIV><FONT face=3DArial size=3D2>The experimenter who started this =
string, is asking for help as not to waist time and =
money.</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
<DIV> </DIV>
<DIV><FONT face=3DArial size=3D2>Latter, catching tunes.</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
<DIV><BR></DIV>
<BLOCKQUOTE=20
style=3D"PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; =
BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px"><FONT=20
face=3Darial,helvetica><FONT size=3D2>Greets! <BR><BR>The problem with =
all you=20
neo-nerds who have no time for instant gratification <BR>is you waste =
our time=20
with your endless whining :) <BR><BR>Happy Ears! <BR>Al =
B^}=20
<BR><BR></BLOCKQUOTE></FONT></FONT></BODY></HTML>
- ------=_NextPart_000_0048_01C127E8.1F143B00--
=========================================================================
From: TubeGarden@aol.com
Subject: Re: [JN] R76 listening impressions, questions, and new amp topology: 76->71A...
Date: Sat, 18 Aug 2001 13:32:22 EDT
Source: Sound Digest Archive v02.n949
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In a message dated 8/18/01 10:22:41 AM US Mountain Standard Time,
jimpcn@sympatico.ca writes:
> neo-nerds who have no time for instant gratification
Greets!
No, it is a joke, get it? Too busy for instant gratification?
Get it?
Happy Ears!
Al B^}
- --part1_11a.35e7c01.28b000a6_boundary
Content-Type: text/html; charset="US-ASCII"
Content-Transfer-Encoding: 7bit
<HTML><FONT FACE=arial,helvetica><BODY BGCOLOR="#ffffff"><FONT SIZE=2>In a message dated 8/18/01 10
:22:41 AM US Mountain Standard Time,
<BR>jimpcn@sympatico.ca writes:
<BR>
<BR>
<BR><BLOCKQUOTE TYPE=CITE style="BORDER-LEFT: #0000ff 2px solid; MARGIN-LEFT: 5px; MARGIN-RIGHT: 0px
; PADDING-LEFT: 5px">neo-nerds who have no time for instant gratification </FONT><FONT COLOR="#0000
00" SIZE=3 FAMILY="SANSSERIF" FACE="arial" LANG="0"></BLOCKQUOTE>
<BR></FONT><FONT COLOR="#000000" SIZE=2 FAMILY="SANSSERIF" FACE="Arial" LANG="0">
<BR>
<BR>Greets!
<BR>
<BR>No, it is a joke, get it? Too busy for instant gratification?
<BR>
<BR>Get it?
<BR>
<BR>Happy Ears!
<BR>Al B^}
<BR></FONT></HTML>
- --part1_11a.35e7c01.28b000a6_boundary--
=========================================================================
From: "Leonard Scheepsma (ETM)" <Leonard.Scheepsma@etm.ericsson.se>
Subject: [JN] Radford Analyzer
Date: Wed, 5 Jan 2000 12:58:26 +0100
Source: Sound Digest Archive v02.n386
Joes,
Happy new year to you all, may we all carry the vacuum tube into the new millennium!
I'm looking for some infor WRT a distortion measuring set from Radford UK, consisting of a low disto
rtion oscillator (LDO series 3) and a distortion meter DMS Series 3, which I happen to have but cann
ot operate since no manuals available. Schematics more than welcome as well.
Anyone familiar with this gear (UK Joes??)
leonard
Leonard Scheepsma
Business Development Manager
Ericsson Radio Systems AB
Torshamnsgatan 33 Kista
SE-164 80 STOCKHOLM
Sweden
Tel.+31-161-242711, Fax. +31-161-242663, GSM. +31-6-5474-6331
E-Mail: leonard.scheepsma@etm.ericsson.se
=========================================================================
From: David Dlugos <planet10@pinc.com>
Subject: [JN] Radford MD6
Date: Tue, 14 Nov 2000 08:09:45 -0800
Source: Sound Digest Archive v02.n732
Does anyone know anything about this driver? Made by Isophon.
dave
____________________________________
Transmission Line Speaker Page
http://www.t-linespeakers.org/
New! FALL: The 5-buck amp
New! Chris Bobiak's variation on a Daline
software updated (1/10/2k) . Martin J King's TL model
=========================================================================
From: "Snoopy" <tcma@netvigator.com>
Subject: [JN] Radford TT-100 Power Amp.
Date: Sat, 16 Dec 2000 22:21:44 +0800
Source: Sound Digest Archive v02.n760
Grateful if anybody could direct me to the circuit diagram of Radford TT-100
stereo power amp which I have just acquired.
It is uisng transistor input circuit and driver stage. Power tubes are 2 x
KT-88 to 100 Watt specification per channel. It is using massive output
transformers (should be Partridge as far as I know) and power transformers.
At the back, for each tube there is one test point for checking the bias of
each tube and one potentiometers for adjusting the bias. Can anybody tell
me what's the most suitable bias voltage?
Any advice is greatly appreciated! Thank you in advance.
Best Regards,
Tung-cheung MA
HONG KONG
=========================================================================
From: "Jan Hass" <jh@hifi-analyse.dk>
Subject: Sv: [JN] Radford TT-100 Power Amp.
Date: Sat, 16 Dec 2000 17:02:53 +0100
Source: Sound Digest Archive v02.n761
Hi Snoopy
Sorry I can´t help you with the diagram.
Lucky you.
Just wanted to let you know - you probably know already - that this power amp is quite unique. One o
f my friends owned a Radford TT-100 power amp that he upgraded. It is by far the most powerfull trad
itional tube power amp I have ever heard. He´s amp delivered almost 2 x 200 watts measured the rig
ht way.
The TT-100 packs tremendous dynamics and it have a fantastic top to bottom balanced sound with a sol
idity in the bottom octaves that vere almost chocking.. made expensive SS equipment sound crappy in
this area.
In short : a great amp.
Merry Christmas - Jan Hass
- -----Oprindelig meddelelse-----
Fra: Snoopy <tcma@netvigator.com>
Til: <sound@deliverator.io.com>
Dato: 16. december 2000 15:44
Emne: [JN] Radford TT-100 Power Amp.
>Grateful if anybody could direct me to the circuit diagram of Radford TT-100
>stereo power amp which I have just acquired.
>
>It is uisng transistor input circuit and driver stage. Power tubes are 2 x
>KT-88 to 100 Watt specification per channel. It is using massive output
>transformers (should be Partridge as far as I know) and power transformers.
>At the back, for each tube there is one test point for checking the bias of
>each tube and one potentiometers for adjusting the bias. Can anybody tell
>me what's the most suitable bias voltage?
>
>Any advice is greatly appreciated! Thank you in advance.
>
>Best Regards,
>
>Tung-cheung MA
>HONG KONG
>
>
=========================================================================
From: Owen Young <oyoung@clear.net.nz>
Subject: Re: [JN] Radford TT-100 Power Amp.
Date: Sun, 17 Dec 2000 16:31:30 +1300
Source: Sound Digest Archive v02.n761
Tung
The Kiewa Valley site has a lot of British Vintage stuff.
Don't recall if radford is included, however there may be a link.
Regards
Owen
Snoopy wrote:
>
> Grateful if anybody could direct me to the circuit diagram of Radford TT-100
> stereo power amp which I have just acquired.
=========================================================================
From: Owen Young <oyoung@clear.net.nz>
Subject: Re: [JN] Radford TT-100 Power Amp.
Date: Sun, 17 Dec 2000 21:20:05 +1300
Source: Sound Digest Archive v02.n761
Hi Tung,
Sorry, the URL is:
http://home.mira.net/~kiewavly/
Owen
=========================================================================
From: "Snoopy" <tcma@netvigator.com>
Subject: Re: [JN] Radford TT-100 Power Amp.
Date: Sun, 17 Dec 2000 23:33:08 +0800
Source: Sound Digest Archive v02.n761
Hi Jan,
*******Jan wrote:
One of my friends owned a Radford TT-100 power amp that he upgraded. It is
by far the most powerfull traditional tube power amp I have ever heard. He´s
amp delivered almost 2 x 200 watts measured the right way.
The TT-100 packs tremendous dynamics and it have a fantastic top to bottom
balanced sound with a solidity in the bottom octaves that vere almost
chocking.. made expensive SS equipment sound crappy in this area.
In short : a great amp.************
Thank you for your advice. Do you know how you friend upgrade the TT-100?
Regards,
Tung-cheung MA
HONG KONG
=========================================================================
From: "Jan Hass" <jh@hifi-analyse.dk>
Subject: Sv: [JN] Radford TT-100 Power Amp.
Date: Mon, 18 Dec 2000 22:14:21 +0100
Source: Sound Digest Archive v02.n762
Hi Snoopy
I have no contact with my friend with the Radford TT 100 anymore. I am pretty sure he remowed the SS
stuff since he was a hard core bottlehead and he beefed up the PSU. Sorry thats all I remember abou
t the technical aspects. What I remember more clearly is the impressing reproduction of this amp !
Merry X-mas - Jan Hass
- -----Oprindelig meddelelse-----
Fra: Snoopy <tcma@netvigator.com>
Til: <sound@deliverator.io.com>
Dato: 17. december 2000 16:52
Emne: Re: [JN] Radford TT-100 Power Amp.
>Hi Jan,
>
>*******Jan wrote:
>One of my friends owned a Radford TT-100 power amp that he upgraded. It is
>by far the most powerfull traditional tube power amp I have ever heard. He´s
>amp delivered almost 2 x 200 watts measured the right way.
>The TT-100 packs tremendous dynamics and it have a fantastic top to bottom
>balanced sound with a solidity in the bottom octaves that vere almost
>chocking.. made expensive SS equipment sound crappy in this area.
>In short : a great amp.************
>
>Thank you for your advice. Do you know how you friend upgrade the TT-100?
>
>Regards,
>
>Tung-cheung MA
>HONG KONG
>
>
=========================================================================
From: "Snoopy" <tcma@netvigator.com>
Subject: Re: [JN] Radford TT-100 Power Amp. - Thanks
Date: Sat, 23 Dec 2000 20:10:08 +0800
Source: Sound Digest Archive v02.n768
Dear all,
Thank Jan Hass, K. Kessler and Owen Young who have responded and advised
me. Particular thanks to Mike Davis who had hand-drawn and faxed a circuit
diagram of Radford TT-100 to me (living oversea), and Graham Ingle who
mailed a circuit diagram of Sondex S-100 (very similar to TT-100) to me.
Thanks really!
Wishing all joenetters a Merry X'mas 2000 & Happy New Year 2001!
Best Regards,
T.C. MA
HONG KONG
=========================================================================
From: "Multi-Volti Devices" <multi-volti@softhouse.com>
Subject: [JN] radial & axial
Date: Mon, 12 Apr 1999 00:39:35 -0400
Source: Sound Digest Archive v02.n121
Hello:
There are plenty of things I have trouble remembering, but somehow I found a
way to remember these...
Axial...the leads are in a straight line, as though the conductor is thru
the axis of the component.
Radial...the leads are positioned at the radii of the circle constituting
the body of the component.
I stopped there...if you think about it too much, you can talk yourself into
the opposite. I did once, anyway.
Murray
=========================================================================
From: Paul Joppa <pdj@ISDNseattle.net>
Subject: Re: [JN] radial & axial
Date: Tue, 13 Apr 1999 20:42:37 -0700
Source: Sound Digest Archive v02.n123
Ah, yes - is it
"Twinkle, twinkle, little star,
Power equals I-squared R"
or
"Little star up in the sky,
Power equals R-squared I"?
- -Paul
Multi-Volti Devices wrote:
>
> Hello:
>
> There are plenty of things I have trouble remembering, but somehow I found a
> way to remember these...
>
> Axial...the leads are in a straight line, as though the conductor is thru
> the axis of the component.
>
> Radial...the leads are positioned at the radii of the circle constituting
> the body of the component.
>
> I stopped there...if you think about it too much, you can talk yourself into
> the opposite. I did once, anyway.
>
> Murray
=========================================================================
From: "Michael (Mick)Maloney" <supra@cantech.net.au>
Subject: [JN] Radial horns
Date: Thu, 07 Jun 2001 21:05:13 +0800
Source: Sound Digest Archive v02.n902
- --=======2C1D232F=======
Content-Type: text/plain; x-avg-checked=avg-ok-254C71AE; charset=us-ascii
Any OzJoes interested in a pair of round front loading horns- mouth
diameter of 1 metre, acoustic roll off about 150Hz.
Were set up for Axiom 80's (I'm keeping them-they really are the best
available) but any coaxial around 9-10" ok.
Made from fiberglass with white gloss finish-spectacular looks and dynamics.
AUD 250.Plus freight. Could even be convinced to sell Grand Onken/Alnico
15" Altecs to sit underneath them.
MickM
- --=======2C1D232F=======--
=========================================================================
From: Steve Van Osdell <svanos@queencity.com>
Subject: [JN] Radian 950PB compression driver
Date: Mon, 04 Sep 2000 21:46:02 -0400
Source: Sound Digest Archive v02.n653
Has anyone heard anything good or bad about this 2" compression driver?
I also heard that Radian has out a nice little studio monitor with a
very high (over 100) SPL.
Thanks, Steve
=========================================================================
From: "tovestef" <tovestef@get2net.dk>
Subject: Sv: [JN] Radian 950PB compression driver
Date: Tue, 5 Sep 2000 19:52:52 +0200
Source: Sound Digest Archive v02.n654
Hi Steve
> Has anyone heard anything good or bad about this 2" compression driver?
> I also heard that Radian has out a nice little studio monitor with a
> very high (over 100) SPL.
>
> Thanks, Steve
>
>
If I am not all wrong, it is that driver, that is in the midrangehorn of Peter Bahnsens Magnificator
horns. And that sounded good, allthough i think Peter did some mods to it!??!!
:-)
Steffen Lorenzen
Barsmark Bygade 85
DK 6200 Aabenraa
Tlf.: 74618190
tovestef@get2net.dk
=========================================================================
From: evaguido <EvaGuido@iaehv.nl>
Subject: Re: [JN] Radian 950PB compression driver
Date: Tue, 05 Sep 2000 20:23:40 +0200
Source: Sound Digest Archive v02.n654
Hi
I heard Radian at Frankfurter messe. Both 12 and 15 inch coaxial drivers in
relatively small cabinets
Excelent sound, best of what I heard....
I do not know exact types of units used
Guido
At 21:46 04/09/2000 -0400, Steve Van Osdell wrote:
>Has anyone heard anything good or bad about this 2" compression driver?
>I also heard that Radian has out a nice little studio monitor with a
>very high (over 100) SPL.
>
>Thanks, Steve
>
>
>
=========================================================================
From: Steve Van Osdell <svanos@queencity.com>
Subject: [JN] Radian Co-axial speakers
Date: Mon, 04 Sep 2000 21:51:21 -0400
Source: Sound Digest Archive v02.n653
I found some information on some interesting co-axial speakers from
Radian. Has anyone had any experience with these? See link below.
http://www.radianaudio.com/products/coaxial/15_in.html
Thanks, Steve
=========================================================================
From: "Mike Wurtz" <mikewurtz@mindspring.com>
Subject: [JN] Radian drivers
Date: Mon, 14 Feb 2000 10:03:33 -0600
Source: Sound Digest Archive v02.n448
Where can I look at and buy Radian drivers like the 475.
mike wurtz
=========================================================================
From: Thomas Danley <Tom@ppci.com>
Subject: Re: [JN] Radian drivers
Date: Mon, 14 Feb 2000 15:10:55 -0500
Source: Sound Digest Archive v02.n449
Mike Wurtz wrote:
> Where can I look at and buy Radian drivers like the 475.
>
> mike wurtz
Hi Mike, all
Radian has a website and also B&C makes a couple nice compression
drivers too.
http://www.bcspeakers.com/
http://radianaudio.com/
4, Audax HM100Z0 work well in the horn you mentioned, maybe I will be
able to supply purpose built drivers which are about +2 dB more
efficient.
Tom
=========================================================================
From: "c.k. kok" <vt4c@hotmail.com>
Subject: [JN] Re: Radian speaker
Date: Thu, 04 May 2000 04:03:15 GMT
Source: Sound Digest Archive v02.n539
Hi Joes,
Tom wrote :-
>
>I use Radian replacement diaphragms in several sets of Altec and JBL
> >compression drivers; they're high quality, rugged, good sounding and
> >relatively cheap, about $50 for 1" diaphragms from Image Communications
> >in Rockford Illinois, the 475 sells for only $150. Tom Brennan
>http://community.webtv.net/irishtom/TommysHornSpeaker
>
How can I get in touch with Image Communications? Do they have an
e-mail address? Thanks.
Cheers,
C.K.
________________________________________________________________________
Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com
=========================================================================
From: "Richard B. Curtis" <rbc@pacbell.net>
Subject: Re: [JN] Radian speakers
Date: Sun, 16 Apr 2000 09:32:41 -0700
Source: Sound Digest Archive v02.n521
evaguido wrote:
> Does any among you have experience with Radian speakers ?
>
> Guido:
> Bruce Edgar thinks highly of Radian compression drivers, and believes they
> are worth experimenting with. I have found from my own experience that the
> Radian aluminum replacement diaphram for the Altec 802 is arguably as good or
> better than the original Altec aluminum part, and is more extended than the
> Altec symbiotic version of the diaphram. It has a mylar surround similar to
> the TAD 2000, and therefore might go lower than the original Altec if you
> remove the back chamber. I believe Radian also makes a rare-earth magnet 4"
> compression driver somewhat similar to TAD 4000, but at a much reduced
> price. I would imagine others on this list have had some experience with
> radian drivers.
Rich Curtis
>
=========================================================================
From: irishtom@webtv.net (tom brennan)
Subject: Re: [JN] Radian speakers
Date: Sun, 16 Apr 2000 10:55:37 -0500 (CDT)
Source: Sound Digest Archive v02.n521
Guido---I heard Radian's top 1" compression driver, the 475, in Tom
Danley's Unitys, outstanding, never heard better. I use Radian
replacement diaphragms in several sets of Altec and JBL compression
drivers; they're high quality, rugged, good sounding and relatively
cheap, about $50 for 1" diaphragms from Image Communications in Rockford
Illinois, the 475 sells for only $150. It's interesting that you heard
the co-axes, they appear to be excellent bargains but I never heard
them. A little bit of chauvinism here: it's good to see American made
products like this that compete in both quality and price.
Tom Brennan
http://community.webtv.net/irishtom/TommysHornSpeaker
=========================================================================
From: Chris and Susan Beck <n9zes@execpc.com>
Subject: Re: [JN] Radian speakers
Date: Sun, 16 Apr 2000 11:55:16 -0500
Source: Sound Digest Archive v02.n521
Dr. Edgar has also had very good luck with the Selenium compression drivers and
such. He says the big 2" units make a GREAT midrange horn driver, but require a
supertweeter on top. He's very impressed with the stringent quality requirements
of Selenium, stating that he has a buddy that is involved with winding the voice
coils for them.
Chris
"Richard B. Curtis" wrote:
> evaguido wrote:
>
> > Does any among you have experience with Radian speakers ?
> >
>
> > Guido:
>
> > Bruce Edgar thinks highly of Radian compression drivers, and believes they
> > are worth experimenting with. I have found from my own experience that the
> > Radian aluminum replacement diaphram for the Altec 802 is arguably as good or
> > better than the original Altec aluminum part, and is more extended than the
> > Altec symbiotic version of the diaphram. It has a mylar surround similar to
> > the TAD 2000, and therefore might go lower than the original Altec if you
> > remove the back chamber. I believe Radian also makes a rare-earth magnet 4"
> > compression driver somewhat similar to TAD 4000, but at a much reduced
> > price. I would imagine others on this list have had some experience with
> > radian drivers.
>
> Rich Curtis
>
> >
=========================================================================
From: evaguido <EvaGuido@iaehv.nl>
Subject: [JN] Radian speakers
Date: Sun, 16 Apr 2000 14:11:16 +0200
Source: Sound Digest Archive v02.n521
Hi all,
Does any among you have experience with Radian speakers ?
I heard them at the recent Frankfurter Music Messe and was surprised by
their sound. To me absolute best at the show and above average high-end
(whatever that may be).
Very clean, good focus and open sound with lots of details. May be somewhat
small staging, deep bass was lacking but not disturbing.
I listened to a 12" coaxial unit, with some 95 dB efficiency.
www.radianaudio.com
regards
=
Guido
=========================================================================
From: David Barnett <d_n_b@swbell.net>
Subject: Re: [JN] Radian speakers
Date: Sun, 16 Apr 2000 16:43:44 -0500
Source: Sound Digest Archive v02.n521
On Sun, 16 Apr 2000 10:55:37 -0500 (CDT), irishtom@webtv.net (tom
brennan) wrote:
> I use Radian
>replacement diaphragms in several sets of Altec and JBL compression
>drivers; they're high quality, rugged, good sounding and relatively
>cheap, about $50 for 1" diaphragms from Image Communications in Rockford
>Illinois
Does Radian have a replacement diaphragm for the 075 ring tweeter?
- --dnb
=========================================================================
From: Roscoe Primrose <roscoe@aiko.com>
Subject: Re: [JN] Radian speakers
Date: Mon, 17 Apr 2000 11:58:57 -0400
Source: Sound Digest Archive v02.n523
evaguido wrote:
>
> hi all
>
> Got lots of positive reactions on the Radian mail. Their managing director
> Richard Contrimas pointed me out that their replacement diagrams are most
> of the time better than the original ones, and cheaper.
>
> Given you repsonse that seems to be true, if not at least confirmed.
>
> You may look at the website for details among replacements.
Unfortuantely, according to the info on the website, they don't make
replacements for 288s...
Peace
- --
Roscoe Primrose -- mailto:roscoe@aiko.com --
http://www.aiko.com/roscoe
"Once in a while you get shown the light
In the strangest of places if you look at it right." Robert Hunter
"640K ought to be enough for anybody" , Bill Gates, 1981
=========================================================================
From: Steven <stevensl@mindspring.net>
Subject: Re: [JN] Radian speakers
Date: Mon, 17 Apr 2000 12:13:40 -0400 (EDT)
Source: Sound Digest Archive v02.n523
I wonder how good their woofers are?
the specs look good but since when does that really matter ;-)
`~`~`~`~`~`~`~`~`~`~`~`~`~`~`~`~`~`~`~`~`~`~`~`~`
Steven St.Laurent 403forbidden.net
stevensl@mindspring.net
`~`~`~`~`~`~`~`~`~`~`~`~`~`~`~`~`~`~`~`~`~`~`~`~`
=========================================================================
From: evaguido <EvaGuido@iaehv.nl>
Subject: Re: [JN] Radian speakers
Date: Mon, 17 Apr 2000 17:34:32 +0200
Source: Sound Digest Archive v02.n523
hi all
Got lots of positive reactions on the Radian mail. Their managing director
Richard Contrimas pointed me out that their replacement diagrams are most
of the time better than the original ones, and cheaper.
Given you repsonse that seems to be true, if not at least confirmed.
You may look at the website for details among replacements.
regards,
- -
Guido
=========================================================================
From: evaguido <EvaGuido@iaehv.nl>
Subject: Re: [JN] Radian speakers
Date: Mon, 17 Apr 2000 20:06:28 +0200
Source: Sound Digest Archive v02.n523
Roscoe,
You may send an Email to RichardK@radian.com. He is the president and may
be sensitive for suggestions
regards,
=
Guido
>Unfortuantely, according to the info on the website, they don't make
>replacements for 288s...
>
>Peace
>--
>Roscoe Primrose -- mailto:roscoe@aiko.com --
>http://www.aiko.com/roscoe
>
>"Once in a while you get shown the light
>In the strangest of places if you look at it right." Robert Hunter
>
>"640K ought to be enough for anybody" , Bill Gates, 1981
>
>
=========================================================================
From: evaguido <EvaGuido@iaehv.nl>
Subject: Re: [JN] Radian speakers
Date: Mon, 17 Apr 2000 20:11:38 +0200
Source: Sound Digest Archive v02.n523
At 12:13 17/04/2000 -0400, Steven wrote:
>
>I wonder how good their woofers are?
>the specs look good but since when does that really matter ;-)
Could anyone indicate whether these are suitable for horn lading ? (are you
listening Bert ?)
Guido
>`~`~`~`~`~`~`~`~`~`~`~`~`~`~`~`~`~`~`~`~`~`~`~`~`
> Steven St.Laurent 403forbidden.net
> stevensl@mindspring.net
>
>`~`~`~`~`~`~`~`~`~`~`~`~`~`~`~`~`~`~`~`~`~`~`~`~`
>
>
>
>
>
=========================================================================
From: Patrick Currie <tubesguy@chorus.net>
Subject: Re: [JN] Radian speakers
Date: Mon, 17 Apr 2000 17:06:51 -0500 (CDT)
Source: Sound Digest Archive v02.n524
>Unfortuantely, according to the info on the website, they don't make
>replacements for 288s...
>
>Peace
>--
>Roscoe Primrose
Hmm -
That may explain why that pair of Altec replacements went for $300 on eBay
last week. - Pat
=========================================================================
From: "Richard B. Curtis" <rbc@pacbell.net>
Subject: Re: [JN] Radian speakers
Date: Mon, 17 Apr 2000 17:30:00 -0700
Source: Sound Digest Archive v02.n524
I realized that I sent the following message only to Roscoe Primrose
instead of broadcasting it. I am re-sending it in case anyone is stuck
with Altec 288 magnets and no diaphrams. It may be of use to some of
you Joes out there.
Roscoe Primrose wrote:
Unfortunately, according to the info on the website, [Radian doesn't]
make replacements for 288s...
Dear Roscoe (and anyone else needing 288 diaphrams):
I have had success with Epitome titanium replacement diaphrams
for the 288 C's. It is Epitome part number 1072PT I think, but check
with Image Communications to make sure of the correct model designation
of the 288 replacement diaphram. They will advise you. The diaphram is
actually made for an Epitome driver, but fits the 288C and later
models. We out here in Sodom have tested them against the original
Altec aluminum diaphrams (not the pascalite or symbiotic versions) and
found the Epitomes to be both smoother and more extended. This is
puzzling, because titanium is heavier than aluminum; perhaps the greater
strength of titanium allows for a thinner diaphram. They are
approximately $23.00 a piece (yes, that's right, only $23 wholesale from
Image).
My 288's came from the Market Street Cinema in San Francisco; the
original aluminum diaphrams were blown out when the theatre changed from
movies to one of SF's major strip joints. Though my living room horns
once serenaded some of the more notorious porn stars of the 70's and
80's, they now serve as conduits for St. Matthew's Passion (please no
jokes about horniness; the Hiraga crossover eliminated that annoying
quality). The only problem I encountered with the Epitomes was that only
three of the holes lined up over the 288's alignment posts; the fourth
post hit solid plastic. Consequently, I used the blown Altec diaphram
as a template to drill the fourth hole in the Epitome outer ring. It
worked perfectly. You might not encounter this problem, but if you do,
it's solvable.
Richard Curtis, San Francisco
=========================================================================
From: "Bert Doppenberg" <LCH@lowther.nl>
Subject: Re: [JN] Radian speakers
Date: Mon, 17 Apr 2000 21:04:15 +0200
Source: Sound Digest Archive v02.n524
Hi All,
> >I wonder how good their woofers are?
> >the specs look good but since when does that really matter ;-)
>
> Could anyone indicate whether these are suitable for horn lading ? (are
you
> listening Bert ?)
I am listening....
I've looked at the specs yesterday and are better for use in reflex-system
(Onken?). The usable bandwidth would be too small (2Fs/Qts).
Bert,
- ------
E-mail:
BD-Design : Sales@lowther.nl
Lowther Club Holland : LCH@lowther.nl
Homepage : http://www.lowther.nl
Oris 150 : http://www.lowther.nl/wwwpages/opinions.html
Phone/Fax : +31 341 254500 Mobile: +31 6 51242990
=========================================================================
From: evaguido <EvaGuido@iaehv.nl>
Subject: Re: [JN] Radian speakers
Date: Mon, 17 Apr 2000 23:20:50 +0200
Source: Sound Digest Archive v02.n524
Bert saiz
>I am listening....
Hi Bert
>I've looked at the specs yesterday and are better for use in reflex-system
>(Onken?). The usable bandwidth would be too small (2Fs/Qts).
Bass reflex is what Radian put them into as well
thanks,
Guido
>Bert,
>
>------
>
>E-mail:
>
>BD-Design : Sales@lowther.nl
>
>Lowther Club Holland : LCH@lowther.nl
>
>Homepage : http://www.lowther.nl
>
>Oris 150 : http://www.lowther.nl/wwwpages/opinions.html
>
>Phone/Fax : +31 341 254500 Mobile: +31 6 51242990
>
>
>
>
>
=========================================================================
From: Phil <tube@jump.net>
Subject: [JN] Re: Radioactive tubes
Date: Sun, 05 Nov 2000 03:51:14 -0600
Source: Sound Digest Archive v02.n721
Did anyone see the eBay auction for an Eimac VT-127A? It can be seen at:
http://cgi.ebay.com/aw-cgi/eBayISAPI.dll?ViewItem&item=482758259&ed=973390463
He mentioned that it uses uranium glass for the seals, emitting about 0.2
mR/hr. Now
that's not much--at sea level we get about 100 mRads/yr from the earth and
cosmic
rays, but still ... He also has photos under a black light. I have a black
light, so I put a
few of my tubes under it. Of the Eimacs, 9 out of 9 304TL, 3 of 3 304TH, 1 of 1
100TH,
1 of 1 3C24, 4 of 4 35TG, 1 of 3 35T, and 0 of 1 4-1000A tubes looked just like
the
photos, i.e. definitely radioactive. Hmmm .... don't really know what to think
about this
one. Uranium is not that radioactive--there's a reason that only half has
decayed after
4 billion years--but I would like to have a bit more info on this. I bought a
radiation
detector from Angela a few years back for $5 (are you ready for nuclear war?),
I think
I'll get a battery for it tomorrow and see if it can read these.
By the way 2 of 2 Gammatron 304L tubes had no glow under the black light, but a
Cascade 3C24 as well as two British 10E tubes (sort of 834) did. Also, the
Eimac 35T
tubes that did not glow were in yellow boxes, if that helps to put a time frame
on it. Tubes
from '45 glowed like crazy. For the moment I have them all in a box in the
other end of
the house ...
Radioactive Phil
=========================================================================
From: StepHydro@aol.com
Subject: Re: [JN] Re: Radioactive tubes
Date: Sun, 5 Nov 2000 07:30:23 EST
Source: Sound Digest Archive v02.n722
In a message dated 11/05/2000 6:<BR07:<BR34 AM
Eastern Standard , tube@jump.net writes:
> For the moment I have them all in a box in the other end of the house ...
Interesting post, Phil. It reminds me of something I read years ago during a
radwaste flap in the news.
One wag opined that if the other fellow was queasy about constant bombardment
by low-level radiation, he was living on the wrong planet :-)
Cheers/Carron
=========================================================================
From: "Paul@13E1.com" <triode@bow-tie.org.uk>
Subject: Re: [JN] Re: Radioactive tubes
Date: Sun, 5 Nov 2000 11:51:18 -0000
Source: Sound Digest Archive v02.n722
I recall learning at school that "typically", topsoil covering a square mile
to a depth of a foot, would contain about three tons of uranium and about a
gramme of radium.
Paul de R. Leclercq
- ----- Original Message -----
From: Phil <tube@jump.net>
Cc: <sound@lists.io.com>
Sent: Sunday, November 05, 2000 9:51 AM
Subject: [JN] Re: Radioactive tubes
> Did anyone see the eBay auction for an Eimac VT-127A? It can be seen at:
>
>
http://cgi.ebay.com/aw-cgi/eBayISAPI.dll?ViewItem&item=482758259&ed=97339046
3
>
> He mentioned that it uses uranium glass for the seals, emitting about 0.2
> mR/hr. Now
> that's not much--at sea level we get about 100 mRads/yr from the earth and
> cosmic
> rays, but still ... He also has photos under a black light. I have a black
> light, so I put a
> few of my tubes under it. Of the Eimacs, 9 out of 9 304TL, 3 of 3 304TH, 1
of 1
> 100TH,
> 1 of 1 3C24, 4 of 4 35TG, 1 of 3 35T, and 0 of 1 4-1000A tubes looked just
like
> the
> photos, i.e. definitely radioactive. Hmmm .... don't really know what to
think
> about this
> one. Uranium is not that radioactive--there's a reason that only half has
> decayed after
> 4 billion years--but I would like to have a bit more info on this. I
bought a
> radiation
> detector from Angela a few years back for $5 (are you ready for nuclear
war?),
> I think
> I'll get a battery for it tomorrow and see if it can read these.
>
> By the way 2 of 2 Gammatron 304L tubes had no glow under the black light,
but a
>
> Cascade 3C24 as well as two British 10E tubes (sort of 834) did. Also, the
> Eimac 35T
> tubes that did not glow were in yellow boxes, if that helps to put a time
frame
> on it. Tubes
> from '45 glowed like crazy. For the moment I have them all in a box in the
> other end of
> the house ...
>
> Radioactive Phil
>
>
>
=========================================================================
From: longrie@mmace.nrl.navy.mil
Subject: [JN] Re: Radioactive tubes, Thorium
Date: Mon, 06 Nov 2000 12:59:22 +0000
Source: Sound Digest Archive v02.n723
Did you know that thorium is a radioactive material also?
Thorium 232 occurs naturally, being about as abundant as lead.
Thorium 232, like uranium 238, is classified as a source material by the
Atomic Energy Commission. It is considered to be a nuclear fuel for
future generations. Bombardment of thorium 232 by neutrons yields
uranium 233, an active fissile nuclear fuel. Thorium 232 is sufficiently
radioactive to expose a photographic plate in a few hours.
thought you might want to know that
gary
=========================================================================
From: "Paul@13E1.com" <triode@bow-tie.org.uk>
Subject: Re: [JN] Re: Radioactive tubes, Thorium
Date: Mon, 6 Nov 2000 19:25:53 -0000
Source: Sound Digest Archive v02.n723
Hell Gary, everybody.
Dredging up bits from my schooldays, I seem to recall that Caesium and
Barium too are radio-active.
Is this true?
Paul de R. Leclercq
- ----- Original Message -----
From: <longrie@mmace.nrl.navy.mil>
To: <sound@lists.io.com>
Sent: Monday, November 06, 2000 12:59 PM
Subject: [JN] Re: Radioactive tubes, Thorium
> Did you know that thorium is a radioactive material also?
> Thorium 232 occurs naturally, being about as abundant as lead.
> Thorium 232, like uranium 238, is classified as a source material by the
> Atomic Energy Commission. It is considered to be a nuclear fuel for
> future generations. Bombardment of thorium 232 by neutrons yields
> uranium 233, an active fissile nuclear fuel. Thorium 232 is sufficiently
> radioactive to expose a photographic plate in a few hours.
>
> thought you might want to know that
>
>
> gary
>
>
=========================================================================
From: SBench@aol.com
Subject: Re: [JN] Radio Frequency Pickup
Date: Wed, 17 Jan 2001 00:23:57 EST
Source: Sound Digest Archive v02.n785
In a message dated 01-01-17 00:17:04 EST, pitaro@ozemail.com.au writes:
> Well a small problem has resulted. I am now pickup up am radio signals which
> I wasn't before and they are being amplified quite loudly. I tried
shielding
> the signal to lead to the 5842. Tried shielding the dc wire to the grid of
> the 45. No luck. At the moment the amps are on timber boards for testing so
> I have kept the wires of secondaries on output trannies quite long. If I
> touch or move these I get some static but no reduction in the radion
signal.
> If I pull out the 5842 tubes then the radio signal is gone so I assume it
is
> coming from the front of the amp but I don't know where.
>
> What can I try next to rid the induced signal?
>
Sometimes with 5842, due to the very high gm, these tubes will
oscillate at very high frequency and produce symptoms such as
you mention. If you don't have grid "stopper" resistors on the 5842,
that would be one thing to try: a 200 ohm resistor on EACH of the
4 grid leads directly at the tube socket, then connected together
on the "far" side of the resistors. All grid wiring goes to that
connection point.
The resistors de Q the internal lead inductance/capacitance
circuit; the 4 in parallel help further de Q the system.
Best Regards,
Steve
=========================================================================
From: Joe Roberts <jroberts@io.com>
Subject: Re: [JN] Radio Frequency Pickup
Date: Wed, 17 Jan 2001 00:26:24 -0600
Source: Sound Digest Archive v02.n785
My (last) 417A project was a great 150 mhz paging transmitter receiver.
This tube is hot as hell at RF. Radio guys knew this and took extreme measures
with tubes like this. The devil-may-care audio geeks just wing it and think
they're cool, unless they start picking up the Channel 7 news.
A few inches of wire is a great antenna at 417A capable frequencies. The 417A
is also wildly prone to VHF oscillation with inferior layout.
Try inserting RF chokes in the heater lines (wind a bunch of fine wire on a
long resistor) and stick a .003 matchhead ceramic cap with no leads between the
heater pins.
If that doesn't help, you may want to consider a small value grid bypass cap to
ground with real short leads or an RF choke in series with grid. Remember that
chokes and such are resonant at some frequency and MAY make the problem worse.
Grounding in general must also be valid at RF. I use 3M copper shielding tape
(digikey) as a ground buss along the tube sockets and make connections to the
tape as short as possible. A 1" tape has less than .1 ohm impedance at VHF.
Solder the tube socket frame to the tape also.
The signal is either getting in through the heater line or along the grid. Or
both.
10-4 good buddy,
Joe
"The Voice of Austin"
______________
Harry Pitaro wrote:
> Hi all,
>
> I hope someone can help me with this.
>
> I initially built a direct coupled 5824/45 amp. The 5842 was choke loaded
> and lead acid battery biased. The amp sounded pretty good. I had a single
> power supply for each tube.
>
> Initially I was using some VOT's but I recently completed building a Tannoy
> GRF corner horn (with a LOT of help!!! Definetely do not try this at home)
> and put some Altec 515B drivers in them for bass. My goal is to bi-amp the
> 511B horns with the GRF boxes. I have an EV electronic crossover which seems
> to work ok.
>
> The power trannies for my 45 amp were designed for 2A3's so I have ample
> current capacity. So I figured that if parallel the HT and heaters, I could
> build identical amps for bass and treble for each channel. I did this and
> shared the cathode of the two 45's.
>
> Well a small problem has resulted. I am now pickup up am radio signals which
> I wasn't before and they are being amplified quite loudly. I tried shielding
> the signal to lead to the 5842. Tried shielding the dc wire to the grid of
> the 45. No luck. At the moment the amps are on timber boards for testing so
> I have kept the wires of secondaries on output trannies quite long. If I
> touch or move these I get some static but no reduction in the radion signal.
> If I pull out the 5842 tubes then the radio signal is gone so I assume it is
> coming from the front of the amp but I don't know where.
>
> What can I try next to rid the induced signal?
>
> Thanks,
> Harry.
=========================================================================
From: Roscoe Primrose <roscoe@aiko.com>
Subject: Re: [JN] Radio Frequency Pickup
Date: Wed, 17 Jan 2001 00:42:43 -0500
Source: Sound Digest Archive v02.n785
Harry Pitaro wrote:
>
> Well a small problem has resulted. I am now pickup up am radio signals which
> I wasn't before and they are being amplified quite loudly. I tried shielding
> the signal to lead to the 5842. Tried shielding the dc wire to the grid of
> the 45. No luck. At the moment the amps are on timber boards for testing so
> I have kept the wires of secondaries on output trannies quite long. If I
> touch or move these I get some static but no reduction in the radion signal.
> If I pull out the 5842 tubes then the radio signal is gone so I assume it is
> coming from the front of the amp but I don't know where.
>
> What can I try next to rid the induced signal?
>
Are you using grid stoppers on the 5842s? If not, try a 470ohm resistor
on each grid pin (right on the pin with as little lead as possible).
Peace
- --
Roscoe Primrose
- -- mailto:roscoe@aiko.com -- http://www.aiko.com/roscoe --
"Once in a while you get shown the light
In the strangest of places if you look at it right." Robert Hunter
=========================================================================
From: Monophonic@aol.com
Subject: Re: [JN] Radio Frequency Pickup
Date: Wed, 17 Jan 2001 08:05:03 EST
Source: Sound Digest Archive v02.n785
Try a plate stopper resistor. 50-100 ohms carbon comp, not film or bulk foil.
attach it so there is no lead.
Bruce Nilson
=========================================================================
From: Monophonic@aol.com
Subject: Re: [JN] Radio Frequency Pickup
Date: Wed, 17 Jan 2001 09:07:46 EST
Source: Sound Digest Archive v02.n785
Some film and bulk foil go inductive above 50-100 MHz. Making them part of an
RF oscillator.
From John Camille:
"...For starters ther is no such thing as a non-inductive resistor. At some
frequency the so called non-inductive resistor will start to show a
significant inductive reactance. If the tube and associated circuit has
sufficient gain at that frequency it will oscillate, especially a high Gm
frame grid tube..."
I forget why carbon comps won't oscillate.
Hope this helps.
=========================================================================
From: Andrej Deticek <andrej.deticek@amis.net>
Subject: Re: [JN] Radio Frequency Pickup
Date: Wed, 17 Jan 2001 14:39:36 +0100
Source: Sound Digest Archive v02.n785
Monophonic@aol.com wrote:
> Try a plate stopper resistor. 50-100 ohms carbon comp, not film or bulk foil.
> attach it so there is no lead.
>
> Bruce Nilson
Bruce,
What is wrong with a small size bulk foil resistor used in this application?
To me, bulk foil resistors like a Vishay or Caddock (these I am familiar with)
work fine, apart from being costly.
Regards,
Andrej Deticek
=========================================================================
From: "Harry Pitaro" <pitaro@ozemail.com.au>
Subject: [JN] Radio Frequency Pickup
Date: Wed, 17 Jan 2001 16:12:18 +1100
Source: Sound Digest Archive v02.n785
Hi all,
I hope someone can help me with this.
I initially built a direct coupled 5824/45 amp. The 5842 was choke loaded
and lead acid battery biased. The amp sounded pretty good. I had a single
power supply for each tube.
Initially I was using some VOT's but I recently completed building a Tannoy
GRF corner horn (with a LOT of help!!! Definetely do not try this at home)
and put some Altec 515B drivers in them for bass. My goal is to bi-amp the
511B horns with the GRF boxes. I have an EV electronic crossover which seems
to work ok.
The power trannies for my 45 amp were designed for 2A3's so I have ample
current capacity. So I figured that if parallel the HT and heaters, I could
build identical amps for bass and treble for each channel. I did this and
shared the cathode of the two 45's.
Well a small problem has resulted. I am now pickup up am radio signals which
I wasn't before and they are being amplified quite loudly. I tried shielding
the signal to lead to the 5842. Tried shielding the dc wire to the grid of
the 45. No luck. At the moment the amps are on timber boards for testing so
I have kept the wires of secondaries on output trannies quite long. If I
touch or move these I get some static but no reduction in the radion signal.
If I pull out the 5842 tubes then the radio signal is gone so I assume it is
coming from the front of the amp but I don't know where.
What can I try next to rid the induced signal?
Thanks,
Harry.
=========================================================================
From: evaguido <EvaGuido@iaehv.nl>
Subject: Re: [JN] Radio Frequency Pickup
Date: Wed, 17 Jan 2001 23:15:40 +0100
Source: Sound Digest Archive v02.n785
Joe (nice to hear you !) and others,
At 00:26 17-1-01 -0600, Joe Roberts wrote:
>Grounding in general must also be valid at RF. I use 3M copper shielding tape
>(digikey) as a ground buss along the tube sockets and make connections to the
>tape as short as possible. A 1" tape has less than .1 ohm impedance at VHF.
I like the copper tape but now your assumption is wrong:
Impedance at high frequencies is fully dominated by the loop in which
currents run. Now since the return path is unknown, you cannot define any
impedance
A wire loop, with loop-diamater > 10 times wire diameter, has about 1 nH
each mm, that is about 25 nH each inch
The smaller the loop size, the better the EM coupling between both
conductors, the lower the impedance.
Normal dual wire (as used to power lamps in the home) has about 40% of the
above impedance
Best is fully closed, rigid, triple or something shielded coax, which has
near perfect coupling, and 0.00......1 nH each mmm, assumed that currents
are allowed through the shield (that is why both ends need RF-connection)
>Solder the tube socket frame to the tape also.
That helps, yes
Solder both heaters with small (1 nF) caps to ground. Doing so still
enables you to lift them, DC wise
Guido
>Joe
>"The Voice of Austin"
>
>______________
>Harry Pitaro wrote:
>
>> Hi all,
>>
>> I hope someone can help me with this.
>>
>> I initially built a direct coupled 5824/45 amp. The 5842 was choke loaded
>> and lead acid battery biased. The amp sounded pretty good. I had a single
>> power supply for each tube.
>>
>> Initially I was using some VOT's but I recently completed building a Tannoy
>> GRF corner horn (with a LOT of help!!! Definetely do not try this at home)
>> and put some Altec 515B drivers in them for bass. My goal is to bi-amp the
>> 511B horns with the GRF boxes. I have an EV electronic crossover which seems
>> to work ok.
>>
>> The power trannies for my 45 amp were designed for 2A3's so I have ample
>> current capacity. So I figured that if parallel the HT and heaters, I could
>> build identical amps for bass and treble for each channel. I did this and
>> shared the cathode of the two 45's.
>>
>> Well a small problem has resulted. I am now pickup up am radio signals which
>> I wasn't before and they are being amplified quite loudly. I tried shielding
>> the signal to lead to the 5842. Tried shielding the dc wire to the grid of
>> the 45. No luck. At the moment the amps are on timber boards for testing so
>> I have kept the wires of secondaries on output trannies quite long. If I
>> touch or move these I get some static but no reduction in the radion signal.
>> If I pull out the 5842 tubes then the radio signal is gone so I assume it is
>> coming from the front of the amp but I don't know where.
>>
>> What can I try next to rid the induced signal?
>>
>> Thanks,
>> Harry.
>
=========================================================================
From: "Harry Pitaro" <pitaro@ozemail.com.au>
Subject: RE: [JN] Radio Frequency Pickup
Date: Thu, 18 Jan 2001 09:07:35 +1100
Source: Sound Digest Archive v02.n785
Hi guys,
Thanks for the suggestions. Well I had some 120ohm resistors in my toolbox
so I cut one end really short, soldered them to the grids of the 5842,
paralleled the other end and connected it to the signal input. No effect,
still picking up radio signals. Also, the amplitude of the radio signal
seems to oscillate regularily. If I take out one of the 5842 tubes the radio
signal is still there but the oscillation stops.
I think it was Joe who suggested a small RF inductor across the heater pins.
I'll give that a go tonight. Are there any other things I could try?
Cheers,
Harry.
=========================================================================
From: "Harry Pitaro" <pitaro@ozemail.com.au>
Subject: RE: [JN] Radio Frequency Pickup
Date: Thu, 18 Jan 2001 22:33:57 +1100
Source: Sound Digest Archive v02.n786
Hi all,
After trying the suggestion of combining the grids of the 5842 with some
small resistors with no success, I tried placing a .47uF cap in series with
the grid resistors of the 5842 to see if could eliminate a source of input
into the tube. This had no success as well. So I now beleive, from what
people are telling me, that the only place the RF can now be induced is from
the heaters. I will try the suggestion of a toriodal core and the heater
wires tomorrow and see what happens. I'll also try an inductor in SERIES (
:-)) with the heaters and see if that helps.
How important is layout? Both tubes are only about 2-3 inches apart. I tried
shielding them but that didn't seem to make much difference. There is also a
slight buzz as well as induced RF but when I touch the grid of the 45 with a
probe to measure voltages, the buzz disappears but the RF remains.
This is a little frustrating since I had the amp working and sounding great
as a monoblock. These problems on appeared once in paralleled the power
supply. Could RF be introduced throught the power supply?
Appreciate the help.
Harry.
=========================================================================
From: "Harry Pitaro" <pitaro@ozemail.com.au>
Subject: RE: [JN] Radio Frequency Pickup
Date: Wed, 24 Jan 2001 00:20:17 +1100
Source: Sound Digest Archive v02.n789
Hi all,
Well after much trial and effort I found the cause of the induced RF signal.
Believe it or not, it was poor earthing rather than heater or grid induced
RF. I found that the active crossover that was introduced to the system was
not earthed properly and it caused the RF pickup. When I removed the RCA
connectors from the amp, the RF was still there but at a very much reduced
volume. Later I found that if I used an extension cord and used a different
wall socket, the RF was totally illuminated. I live on the second floor of
an 80 year old building and the power lines are only a few meters away from
the wall socket that I was initially using. I'm think that the induced RF in
the power lines was affecting that particular wall socket or that the RF
induced in the cables of that wall socket was not being grounded properly.
So when I tried a different wall socket, the RF totally disappeared. Either
the new socket has better earthing or it is far enough away from the power
lines to not be affected.
Now I only have a small amount of hum to contend with which I'm sure will
disappear once I get the amps off the timber boards and onto a well earthed
chassis. I will probably not use the active crossover but will filter the
signal at the input of the power amp. I'm using a 417a transformer coupled
linestage and was wondering what affect, in terms of load on the tube, etc.,
would result if I just paralleled the secondary to the two power amps?
Thanks to everyone who tried to help me with the RF problem. I do appreciate
it.
Harry.
=========================================================================
From: blackie <tubesville@yahoo.com>
Subject: Re: [JN] Radio Shack 40-1197 speakers
Date: Sun, 16 Jul 2000 15:55:49 -0700 (PDT)
Source: Sound Digest Archive v02.n605
- --- Power.Ralph@epamail.epa.gov wrote:
> I would like to use something like the RS 40-1197
> drivers in a .2 cubic foot
> box or something like that. Has anybody tried that
> with these drivers ?
>
don't count on getting lower the 200hz or so with
these babies...plus a peaky upper mid and high
range...
there's some fostex stuuf that would be better, check
the japanese site at www.fostex.com
if you get the Adobe japanese language update for
Acrobat, you can DL and view box plans as published by fostex.
=====
blackie
blackie@tubesville.com
www.tubesville.com
__________________________________________________
Do You Yahoo!?
Get Yahoo! Mail – Free email you can access from anywhere!
http://mail.yahoo.com/
=========================================================================
From: Power.Ralph@epamail.epa.gov
Subject: [JN] Radio Shack 40-1197 speakers
Date: Sun, 16 Jul 2000 18:36:53 -0400
Source: Sound Digest Archive v02.n605
Hi all,
Lately I've had an overwhelming desire to build a pair of high efficiency,
single driver speakers to drive with my SE 46 amp.
I would like to use something like the RS 40-1197 drivers in a .2 cubic foot
box or something like that. Has anybody tried that with these drivers ?
I know of Al Marcy has built them into a TQWP, but I want to just stick them
in a box since I only need them to go down to 100 hz or so where my
powered sub takes over. Or is the TQWP needed to smooth these babies out ?
I might be interested in Diatones or other smaller, full range drivers for sale
in a box or not for this project if you have them.
Also need any other recommendations for decent, inexpensive mini monitors
that go down to 80 hz or so that will run off a couple of SE watts. The Silloquy
SM-2A3 mini monitors really sound like they would be nice, but then they
are $1200 without stands....
Thanks for any info,
- Ralph
=========================================================================
From: TubeGarden@aol.com
Subject: Re: [JN] Radio Shack 40-1197 speakers
Date: Sun, 16 Jul 2000 19:05:57 EDT
Source: Sound Digest Archive v02.n605
In a message dated 7/16/00 3:42:35 PM US Mountain Standard Time,
Power.Ralph@epamail.epa.gov writes:
> Al Marcy has built them into a TQWP
Yup. Also on the back of edgarhorn 300 Hz tractrix. I am now using the Fostex
FE127 there. Same size, but MUCH smoother.
Happy Ears!
Al B^}
=========================================================================
From: hmdplawr@uxmail.ust.hk
Subject: Re: [JN] Radio Shack 40-1197 speakers
Date: Mon, 17 Jul 2000 10:22:24 -0800
Source: Sound Digest Archive v02.n605
Hi Ralph. I'm in the middle of a small project with those speakers.
While recently in India, I had a couple of cabinets made to the
dimensions recommended on the EIFL page (under FE103 specs). They cost
me about $45 with grill cloths and in a black finish--and even included
some full-range drivers. They already sound surprisingly good with the
Indian drivers. The sound is coherent, and the bass sounds tight and
deep for such a small driver and cabinet. They sound more musical than
Mission 760-something bookshelf speakers. Meanwhile, there are a pair
of RS 40-1197 drivers waiting for me at my parents house in Virginia,
which I will visit in a couple of weeks. I'll bring those back to Hong
Kong and try them out in August. I can let you know how they sound.
David Lawrence
On Sun, 16 Jul 2000 18:36:53 -0400 Power.Ralph@epamail.epa.gov wrote:
>
>
>Hi all,
>
>Lately I've had an overwhelming desire to build a pair of high
>efficiency,
>single driver speakers to drive with my SE 46 amp.
>
>I would like to use something like the RS 40-1197 drivers in a .2 cubic
>foot
>box or something like that. Has anybody tried that with these drivers
>?
>
>I know of Al Marcy has built them into a TQWP, but I want to just stick
>them
>in a box since I only need them to go down to 100 hz or so where my
>powered sub takes over. Or is the TQWP needed to smooth these babies
>out ?
>
>I might be interested in Diatones or other smaller, full range drivers
>for sale
>in a box or not for this project if you have them.
>
>Also need any other recommendations for decent, inexpensive mini
>monitors
>that go down to 80 hz or so that will run off a couple of SE watts. The
>Silloquy
>SM-2A3 mini monitors really sound like they would be nice, but then
>they
>are $1200 without stands....
>
>Thanks for any info,
>
> - Ralph
=========================================================================
From: David Barnett <d_n_b@swbell.net>
Subject: Re: [JN] Radio Shack 40-1197 speakers
Date: Mon, 17 Jul 2000 10:40:41 -0500
Source: Sound Digest Archive v02.n605
On Mon, 17 Jul 2000 14:03:50 +0000 (GMT), "T. Loesch"
<ezee_e@hotmail.com> wrote:
>The D/E/K 110 can be found in some old Fender Twin Reverbs. I have seen more
>than once pretty beaten up units going cheap with the original drivers in
>there.... Jamming Jersy have them 2nd Hand at $ 150 each:
You'll never find a Fender Twin Reverb-Amp fitted with D/E/ 110s,
they're 10" speakers and the Twin used a pair of twelves. It's not
unusual to find D/E120s in a Twin though.
- --dnb
=========================================================================
From: Dan Marshall <mdaniel7@uswest.net>
Subject: Re: [JN] Radio Shack 40-1197 speakers
Date: Mon, 17 Jul 2000 10:51:03 -0700
Source: Sound Digest Archive v02.n605
Here is another option to perhaps consider.
I have been messing about with speakers lately and find a pair of
University 308s (8") to sound quite nice, the black/silver model with
the coaxial horn tweeter. They are not terribly extended on either end,
but cover most of the audio range. One party made some rather
disparaging remarks on the net a while back about University diffusicone
speakers, but, though the 308s use the diffusicone principle, I find
them to sound quite nice, very smooth and musical, not at all ragged or
irritating. No bass though, so they must be used with subs. I have had
the University 312s and 312.200s and, while they sound pretty good, I
think the 308s are a better way to go. Both need subs for good bass, so
why use a 12" for a midrange/midbass.
The little Radio Shack super tweeters using 2uf caps as crossover
sweetens and extend the top end. Those little tweeters seem to sound
pretty good when just picking up the very top end. They are nearly
identical sensitivity to the 308s, 95 dB.
Though the 308s extend well beyond my hearing range and the RS tweeters
are crossing over just below the my upper frequency hearing limit (I
only hear to around 11 kHz anymore), it is still readily apparent to my
ears that the little super tweeters add quite a lot to the high end
clarity and definition. I am not sure I fully understand that. Perhaps
the aging ear hears high frequency transients much better than it hears
steady-state sine waves. Though I don't hear nearly as high as I did
when younger, there is no sense that I have lost anything. A good top
end still sounds as good as ever.
This is an economy speaker project. The 308s and RS tweeters were
bought on eBay for $56 and ~$12 respectively. A pair of medium-sized
bookshelf speakers were bought at a parking lot sale for five bucks, for
the enclosures. The speakers sucked and were promptly removed, but the
enclosures are nice with real walnut veneer and nice grills.
For the woofers, I am using a pair of Dynaudio 30W54s I have had laying
around for a couple years (another eBay bargain, NOS at about 1/3 the
price of new). They are only 92 dB (6 ohms), so need to be biamped.
Just yesterday I tried the old RJ loading principle, but need a much
larger inner baffle as the baffle spacing had to be only an eighth of an
inch, which is too small. It still worked better than you would think.
The bass is not yet as tight and clean as I would like, but it goes on
down and gets the very bottom end very well. I may have to resort to
TLs to get it as clean as I want.
Overall, though not as sensitive as the old Norelcos, the sound is much
better to my ears, more extended (on both ends), much smoother, more
musical, less aggressive, and they don't beam so badly. Anyway, I would
endorse the little University 308s. I don't know about the older
green/gold units though. Perhaps the would be good as well. I once had
a single unit, but this was some 35 years ago. I do recall that its top
end was very clean.
I am not sure about Thorstons endorsement of the JBL 110 series. They
always sounded hard and metallic to my ears. I had a new pair of E or K
110s about 30 years ago, but didn't fancy them, even back then. The kid
had horn-loaded E120 midranges in a PA system a few years back. Didn't
like them either, even for PA use.
Dan Marshall
=========================================================================
From: "Thom Mackris" <thom_mackris@hotmail.com>
Subject: Re: [JN] Radio Shack 40-1197 speakers
Date: Mon, 17 Jul 2000 11:16:10 -0600
Source: Sound Digest Archive v02.n605
Hi Ralph -
I'd stick with a TQWP design, especially after having heard Roscoe's
interpretation of the Andrea Cufoli boxes. When you take into account that
you have to build a stand for mini-monitors, you're not saving any space as
far as footprint is concerned. The construction is not complex, either.
I'm coming from a prejudice toward t-lines & (more recently) TQWP's. All of
the properly implemented t-lines I've heard have a very quick sound to
them - not quite horn-like dynamics, but quick nevertheless. Jeremy was
also sold on this design, and whether or not you can get close to these
characteristic in a small box is certainly subject to experimentation.
The fact that several folks on this list have confirmed that a TQWP
implementation is more or less a sure thing removes some of the uncertainty,
if that's what you're after.
Cheers,
Thom
- ----- Original Message -----
From: <Power.Ralph@epamail.epa.gov>
To: <sound@lists.io.com>
Sent: Sunday, July 16, 2000 4:36 PM
Subject: [JN] Radio Shack 40-1197 speakers
Hi all,
Lately I've had an overwhelming desire to build a pair of high efficiency,
single driver speakers to drive with my SE 46 amp.
I would like to use something like the RS 40-1197 drivers in a .2 cubic foot
box or something like that. Has anybody tried that with these drivers ?
I know of Al Marcy has built them into a TQWP, but I want to just stick them
in a box since I only need them to go down to 100 hz or so where my
powered sub takes over. Or is the TQWP needed to smooth these babies out ?
I might be interested in Diatones or other smaller, full range drivers for
sale
in a box or not for this project if you have them.
Also need any other recommendations for decent, inexpensive mini monitors
that go down to 80 hz or so that will run off a couple of SE watts. The
Silloquy
SM-2A3 mini monitors really sound like they would be nice, but then they
are $1200 without stands....
Thanks for any info,
- Ralph
=========================================================================
From: David Barnett <d_n_b@swbell.net>
Subject: Re: [JN] Radio Shack 40-1197 speakers
Date: Mon, 17 Jul 2000 13:55:25 -0500
Source: Sound Digest Archive v02.n605
On Mon, 17 Jul 2000 16:55:16 +0000 (GMT), "T. Loesch"
<ezee_e@hotmail.com> wrote:
>You are right.... my memory ain't what it used to be. What was that Fender
>Combo with twin 10" Drivers?
The Vibrolux Reverb-Amp.
>I remember depriving a few of the JBL Alnico
>Drivers and replacing with something else in the Early 80's.... The
>guitarists even swore the new Drivers sounded better and I liked the E110's
>and E120's on Vocals quite well....
The guitarists were right -- a Vibrolux with JBLs is shrill city!
- --dnb
=========================================================================
From: "T. Loesch" <ezee_e@hotmail.com>
Subject: Re: [JN] Radio Shack 40-1197 speakers
Date: Mon, 17 Jul 2000 14:03:50 GMT
Source: Sound Digest Archive v02.n605
Hi there,
>Lately I've had an overwhelming desire to build a pair of high efficiency,
>single driver speakers to drive with my SE 46 amp.
Excellent Idea.
>I would like to use something like the RS 40-1197 drivers in a .2 cubic
>foot box or something like that.
Regardless of anything else, that would NOT be high efficiency.... It's no
more efficient than your average modern minimonitor (in the 90db/W/m
region). I think You'd want to go for more than one 1197.... Now if you used
four pieces in a suitable staggered (depth) series parallel arrangement
you'd be still with little money, good and easy impedance but 96db/W/m....
Now that is still not high sensitivity, but at least something to talk
about.
>Also need any other recommendations for decent, inexpensive mini monitors
>that go down to 80 hz or so that will run off a couple of SE watts.
The Altec enclosures for the 604 come to mind, as they will runof a couple
of Watt and are Monitors.... Mini they are not, of course, but you can't
have everything....
My take on a modest size standmounter with good effciency to cover down to
100Hz would be a modest (12" W X 18" H X 8" D) Enclosure using a good
wideband 10" Driver like the JBL D/E/K 110 (Alnico Magnet please) operated
full range and backed up above 6kHz with a JBL Ring Radiator covering
upwards from there.... I'm sure there is a suitable Enclosure in the
madisound Catalogue.
The D/E/K 110 can be found in some old Fender Twin Reverbs. I have seen more
than once pretty beaten up units going cheap with the original drivers in
there.... Jamming Jersy have them 2nd Hand at $ 150 each:
http://www.jamminjersey.com/speakers.htm
They also have the good old "Bullet" and "Slot" JBL Tweeters with Alnico
Magnets, also $ 150 each. Alternatively, suitable (if not as good sounding)
units, mostly far eastern JBL Copies but also the quite good and inexpensive
Selenium ones from Brazil can be found in the Parts Express Catalogue.
This should get you above around 100Hz to 120Hz into the 100db/W/m region
with a minimum in size.
Even cheaper, Eminence has a few semi decent 8" and 10" stamped Basket
Drivers that could be substituted and have a reasonably flat response, good
enough usually to be usuable with only some cone laquering and without
X-Over in similar 2-Way system.
Finally, the JBL LE8 or the 2110 are nice Fullranges too. Jamming Jersy have
listed the 2110 with Alnico Magnets at $ 75 each. Again, I at least would
likely wish for an additional Supertweeter. The LE8 BTW is the original
which has been widely copied in Japan by (among others) Fostex as FX200
and/or F200A (Ceramic and Alnico magnet respectively).
Later T
________________________________________________________________________
Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com
=========================================================================
From: "T. Loesch" <ezee_e@hotmail.com>
Subject: Re: [JN] Radio Shack 40-1197 speakers
Date: Mon, 17 Jul 2000 16:55:16 GMT
Source: Sound Digest Archive v02.n605
Hi there,
>You'll never find a Fender Twin Reverb-Amp fitted with D/E/ 110s,
>they're 10" speakers and the Twin used a pair of twelves. It's not
>unusual to find D/E120s in a Twin though.
You are right.... my memory ain't what it used to be. What was that Fender
Combo with twin 10" Drivers? I remember depriving a few of the JBL Alnico
Drivers and replacing with something else in the Early 80's.... The
guitarists even swore the new Drivers sounded better and I liked the E110's
and E120's on Vocals quite well....
BTW, the E120 needs a larger Box but is equally suited for such a design and
will play both louder and lower....
Later T
________________________________________________________________________
Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com
=========================================================================
From: Robert C Chambers <rchamber@norwich.edu>
Subject: Re: [JN] Radio Shack 40-1197 speakers
Date: Mon, 17 Jul 2000 15:58:37 -0400 (EDT)
Source: Sound Digest Archive v02.n606
Hello-
> I'm coming from a prejudice toward t-lines
In my experience, the word prejudice means an adverse opinion formed
without just grounds or prior to sufficient evidence having been
collected. But I think (by the context) Thom is saying he likes 'em.
Maybe he's coming from a predilection (i.e. an established preference)
for t-lines. I'm not trying to put words in your mouth. Thom? Just
trying to understand.
I guess I have to say that I've had better luck with transmission lines
than with QWTP enclosures. The one QWTP that I have tried is shown in a
photo on xdrive at Graphics/Speakers/rcQWTP.jpg. It used an Eton
7-380-32 woofer-mid. I've tried this one with the front (below the driver)
stuffed with ~1/2 lb of AcoustaStuff and empty. Either way, low frequency
output was extremely erratic - i.e. variable SPL with frequency, BIGTIME!
Listening to the bass line in jazz trio or quartet it's like the bass
player skipped playing some of the notes.
So I think the next thing I would try would be a t-line (or perhaps a
back horn).
> The fact that several folks on this list have confirmed that a TQWP
> implementation is more or less a sure thing ...
Not a sure thing for me, for sure!
The one t-line I've had good luck with (my wife even likes it although
she can't quite hide it behind a plant) is the small Fried C3L, a two
way truncated pyramid enclosure that I put together some time ago from a
driver kit. Unfortunately it needs something to sit upon - for the time
being, the lf unit (a fourth order EQed closed box) from my Swan 4 days.
Good luck finding an answer that works for you!
Regards,
Robert
=========================================================================
From: jon staebler <jons@megsinet.net>
Subject: Re: [JN] Radio Shack 40-1197 speakers
Date: Mon, 17 Jul 2000 16:29:07 -0500
Source: Sound Digest Archive v02.n606
> Date: Sun, 16 Jul 2000 18:36:53 -0400
> From: Power.Ralph@epamail.epa.gov
> Subject: [JN] Radio Shack 40-1197 speakers
>
> Hi all,
>
> Lately I've had an overwhelming desire to build a pair of high efficiency,
> single driver speakers to drive with my SE 46 amp.
>
> I would like to use something like the RS 40-1197 drivers in a .2 cubic foot
> box or something like that. Has anybody tried that with these drivers ?
>
[snip]
Hi Ralph
You never said how you wanted your 0.2 ft^3 distributed, so I wish to
propose a cheap, simple test :) If you already have the drivers, I say
do this:
1) Go the the hdwe store, get yourself 2-2ft hunks of 4" pvc (make the
guy cut it there, nice & square)...pipe I think was a buck a foot?
2) Stop by the fabric store on the way home and nab 16 oz of
polyester. Maybe another 2 bucks for poly (forgot).
3) Slap some mortite/RTV/whatever around the rim
4) Stuff the pipes...for starters just rip the 16oz in half, and
distribute it in TL fashion.
5) Drop the wired driver into the stuffed pipe (leave the usual room in
back and maybe use some thin fiberglass at the top to soak reflections).
6) Lean them against a towel/sock/whatever on the (smooth) wall and
fire 'em up...bases maybe 6-10" from wall/floor junc.
You now have ~0.18 ft^3 of indirect radiating baby TL that will produce
usable (in room) bass to around 50Hz...and highs to maybe 17k+...for the
cost of drivers + 6 bucks and 20 minutes of your life. I have done
about everything except horns with 1197's (incl ~8 ft folded voight
pipes which these kicked the crap out basswise--no offense anyone) and I
keep going back to a little TL.
If you want direct radiators, you will need to blow another 3 bucks on a
pair of PVC elbows, and the drivers will be too small to sit on them so
you'll need to hammer out a little baffle.
Don't get me wrong--the sound will be what the 1197 gives...and this in
particular will be "pipey" and "stuffy"...you will likely not want to
live with it like this, but, if you are like me, you will hear enough to
make you go nuts building "proper" enclosures. If you do, you will
likely want larger cross-sections and less stuffing--but it's your
call--you can trade your bass for stuffiness and you can trade your
pipeyness for bass, among other things...and maybe go nuts doping cones
and/or adding mass or...hmmm, time to meet my caseworker.
Yes, for efficiency you might want to parallel a couple in an over &
under thing (or sideways if you like the against the wall angle), but it
hoses the single-driver thing...
- ---> Idea shamelessly stolen from an old "Simpline" design in SB by John
Cockroft...
It's got its warts, like anything, but considering the drivers at maybe
14 a throw, that's the toughest $34 to beat that I've ever found. FWIW.
Jon Staebler
=========================================================================
From: Power.Ralph@epamail.epa.gov
Subject: Re: [JN] Radio Shack 40-1197 speakers
Date: Tue, 18 Jul 2000 11:47:02 -0400
Source: Sound Digest Archive v02.n606
Hi,
First, much thanks to all who have made some very interesting suggestions
to me regarding my desire to build some kind of cheap/easy monitor sized
speakers that could be driven by a typical SE amp. I know this is a pipe
dream, but I feel compelled to give it a try.
After looking at lots of stuff, I decided to go with the Radio Shack 40-1354A
5.25" full range driver instead of the 40-1197s. This is because my local
Shack was out of the 1197s and also because speaker builder David Weems
and a Valve article, volume 6, I think, claim a nice midrange for the 1354s.
And they were indeed on sale until August for half price.....
I used the dimensions given in the Valve article to use as a guide for my own,
shooting for around .3 cubic foot or 8.5 liters for the enclosure. Not having
time
or tools to build my own, I found some nice .25 cf MDF enclosure kits at Parts
Express online and ordered them. So I have about $100 in them it looks like
at this point. I'll keep everyone informed when I get them up and running.
On another front, I ordered a pair of Fostex FE208 Sigmas to put in my old
Lowther half-width acousta cabinets to give them a try. I'll also report on
those
when they come in.
Thanks again to all for your input,
- Ralph
=========================================================================
From: "Epstein, Jeremy" <JEpstein@ndbcap.com>
Subject: Re: [JN] Radio Shack 40-1197 speakers
Date: Wed, 19 Jul 2000 10:38:56 -0400
Source: Sound Digest Archive v02.n607
Ralph Power writes :
>First, much thanks to all who have made some very interesting suggestions
>to me regarding my desire to build some kind of cheap/easy monitor sized
>speakers that could be driven by a typical SE amp. I know this is a pipe
>dream, but I feel compelled to give it a try.
The folded Voight pipes I built are decent performers. I used 40-1197 but I
think the 40-1354 is indeed a better choice, based on my audition of two
speakers Herbert Jeschke built with this driver. Herb built the VALVE Hawaii
5.0 project, which sound pretty good given the size compromises, and some
nice tall (unfolded) Voight pipes which sound really great.
I'd remember to try the ".98 Lowther tweak" on the whizzer cone - a little
foam or cotton collar around the whizzer between cheek and gum.
>After looking at lots of stuff, I decided to go with the Radio Shack
40-1354A
>5.25" full range driver instead of the 40-1197s.
Based on what I heard of the Hawaii 5.0's, this may indeed be a good choice.
>On another front, I ordered a pair of Fostex FE208 Sigmas to put in my old
>Lowther half-width acousta cabinets to give them a try. I'll also report
on
>those
>when they come in.
Well, now, you're talkin'.
- -j
=========================================
Jeremy Epstein........jepstein@ndbcap.com
=========================================
=========================================================================
From: Power.Ralph@epamail.epa.gov
Subject: [JN] Radio Shack 40-1354 monitors
Date: Fri, 28 Jul 2000 11:44:25 -0400
Source: Sound Digest Archive v02.n612
Hi All,
Lately I seem to be in a speaker building kind of mode so on another
front I want to report on my experiences with the famous Radio Shack
40-1354A full range, whizzer cone drivers in a monitor size box.
I received the 1" MDF cabinet kits from Parts Express last week and began
assembly. The panels are CNC routered to fit together perfectly and create
quite a substantial cabinet. I used polyurethane glue to hold it all together
and it worked very nicely. These are .25 cu ft cabinets which were close
to the .3 cu ft cabinets of the Hawaii speakers referenced in Valve article.
I used the 5" cutout for the RS driver and the 3" tweeter cutout for the 3.5"
long
by 2.75" diameter bass port. I lined the interior with 1.75" reticulated foam
and covered the sides with some very nice walnut grain vinyl contact paper
I got at the Dollar Store ! I wired them up with genuine audiophile approved
Radio Shack rainbow wire and painted the front and back with black semi
gloss latex paint. They look really great in that classic monitor way.
I hooked them up to my SE 46 amp and started listening....
This is a really nice sounding driver once it starts to break in after about 6
hours
or so. The mids are indeed quite good with excellent balance, imaging and micro
dynamics. Jazz and vocals are best, but classical isn't as quite as good
since these speakers don't get "big" very well. They can stand alone with
livable bass but with my powered sub they satisfy on the low end. The mids
are where these babys really shine and a single watt IS enough to get these
pups up and sailing, which was my goal here.
In absolute terms they could use a tad more sparkle on the top, but for the
price
they are incredible. So if you're on a budget, get some particle board, MDF or
plywood and a pair of these drivers and make some real music with that
low powered SE amp that you can't find any speakers for. Crossovers really
do suck. Total coast for the pair with prefab cabinets is about $125 and they
look great. With homemade cabinets you could build these for less than $50.
For my next project, I plan to put a pair of these drivers in the classic TQWP
as they did at the NY Blast. Six foot wedges of 3/4" plywood ought to let
these babies really stretch out ! I'll report back.
- Ralph
=========================================================================
From: Jeremy Epstein <jepstein@shwd.com>
Subject: [JN] Radio Shack Minimus 7's
Date: Wed, 07 Apr 1999 12:55:00 -0400
Source: Sound Digest Archive v02.n113
Hey, I wanted to give a report on the mod I did a month or so ago on
these cheap little speakers. I've been living with it for a little while
now and so I wanted to run down the results.
Doc B. mentioned to me that Speaker Builder had once featured a decent
mod for the Minimus 7, and a little digging (thanks Bill!) turned the
article up. Only a few parts, the stated aim was to a) present a more
amp-friendly load, b) tame a rising high end, and c) even out the
midrange response a little.
The parts for the mod probably cost as much as the speakers do, about 50
or 60 bucks : I got big fat Solen inductors and caps and mounted them on
big fat pieces of polypropylene (a kitchen cutting board in its former
life) and screwed it all onto the back of each speak. The x/o is about
1/3 the size of the speak now, better Dunker factor for sure.
The stated aims seem met : there was a slight drop in efficiency but
this is balanced by a bit better sound at louder volumes once you do get
there. Overall, I'd say the balance becomes a bit more "BBC"-like,
politer high end but still all there and better integrated top to
bottom. The old balance (with 20 cent parts in the stock x/o) maybe made
for a greater sense of air, what with the high end emphasis, but the new
x/o sounds fast and more coherent to me. They are not as much in your
face as they were : overall it's a more balanced sound.
YMMV, FWIW.
- -j
- --
=====================================
Jeremy Epstein .... jepstein@shwd.com
=====================================
=========================================================================
From: "Bart Shepherd - TTM" <bart.shepherd@ttmsolutions.com>
Subject: [JN] Radio Shack Pro LX-5 speakers
Date: Mon, 2 Aug 1999 22:11:39 +1000
Source: Sound Digest Archive v02.n217
Who was it recently talked of these speakers on sell-out for $39.95 each.
I've been looking but local San Diego dealer never heard of them and has
what seems like maybe Mark II models at $79.95.
Anyone know of a store with stock or the part number so I may order?
Thanks,
Bart
=========================================================================
From: "Multi-Volti Devices" <multi-volti@softhouse.com>
Subject: [JN] Radio Shack sources (Nichicon in question).
Date: Sat, 10 Apr 1999 00:13:49 -0400
Source: Sound Digest Archive v02.n119
NEVER trust Radio Shack to be consistent about their vendors. If they can
buy something cheaper from someone else and keep the same nameplate specs,
they'll do it faster than you can think about it. If the uF and V specs are
=, they'll leave the same RS part number in it. I have had this happen more
times than I care for...buying something and trying to get another a year
later.
Murray
=========================================================================
From: Steve Berger <aprilsound@earthlink.net>
Subject: Re: [JN] Radio Shack sources (Nichicon in question).
Date: Sun, 11 Apr 1999 01:33:53 -0400
Source: Sound Digest Archive v02.n119
Multi-Volti Devices wrote:
>
> NEVER trust Radio Shack to be consistent about their vendors. If they can
> buy something cheaper from someone else and keep the same nameplate specs,
> they'll do it faster than you can think about it. If the uF and V specs are
> =, they'll leave the same RS part number in it. I have had this happen more
> times than I care for...buying something and trying to get another a year
> later.
>
> Murray
Hi Kids:
Howsabout the RS silver bearing solder. It used to be great, now ,
its not solder!!!!!!!!!!!
Steve
- --
Steve Berger <http://home.earthlink.net/~aprilsound/>
=========================================================================
From: Roscoe Primrose <roscoe@aiko.com>
Subject: Re: [JN] Radio Shack sources (Nichicon in question).
Date: Sun, 11 Apr 1999 10:25:13 -0400
Source: Sound Digest Archive v02.n119
Steve Berger wrote:
Snip
> Hi Kids:
> Howsabout the RS silver bearing solder. It used to be great, now ,
> its not solder!!!!!!!!!!!
> Steve
Please explain?
Peace
- --
Roscoe Primrose
- -- mailto:roscoe@aiko.com -- http://www.aiko.com/roscoe --
"Once in a while you get shown the light
In the strangest of places if you look at it right." Robert Hunter
=========================================================================
From: "Carter Hendricks" <carter@i1.net>
Subject: Re: [JN] Radio Shack Sourcing
Date: Sun, 11 Apr 1999 20:08:15 -0500
Source: Sound Digest Archive v02.n120
- -----Original Message-----
From: Ellen Oler <ellenoler@earthlink.net>
Joenet <sound@lists.io.com>
Date: 11 April, 1999 8:08 PM
Subject: [JN] Radio Shack Sourcing
>(J Epstein here from my wife's a/c at home)
>
>Their caps have been Nichicons for about two years now, as far as that
goes.
Yeah but-- Somewhere I have a Nichicon catalog
and Nichicon, like Panasonic like everybody else
makes a lot of different type of caps, some good &
some maybe not. If you need hi frequency 250V
caps for a switching supply they've got some special
design LQ* [?-- from memory]... which also sound
ok --but only ok--for filter use. And yes, the Muses*
are designed for audio and sound very, very good.
But there is no reason to suspect that Rat Shack
would sell anything but the very cheapest stuff in their
little plastic bags.
>
>"Look for the two-tone blue, at a dealer near you!"
>
--Carter
*brown.
**green, or black, and cheap enough from
Michael Percy. The Nichicon catalog says
these are "for audio."
=========================================================================
From: "Ellen Oler" <ellenoler@earthlink.net>
Subject: [JN] Radio Shack Sourcing
Date: Sun, 11 Apr 1999 21:15:07 -0400
Source: Sound Digest Archive v02.n120
(J Epstein here from my wife's a/c at home)
I was wondering if anyone had had this same poroblem. The silver bearing
solder with the violet label just doesn't f*cking flow for me. You too, huh?
Well, I'll be.
Their caps have been Nichicons for about two years now, as far as that goes.
"Look for the two-tone blue, at a dealer near you!"
- -j
=========================================================================
From: "Sellek, Grant (TSA)" <Grant.Sellek@transport.sa.gov.au>
Subject: [JN] Radioshack SPL meter correction curves -I have two versions
Date: Sat, 3 Jun 2000 20:07:36 +0930
Source: Sound Digest Archive v02.n562
This message is in MIME format. Since your mail reader does not understand
this format, some or all of this message may not be legible.
- ------_=_NextPart_000_01BFCD47.BC277EE0
Content-Type: text/plain;
charset="iso-8859-1"
Hi all, I have two sets of "correction tables" for my analog
Radioshack SPL meter. They deviate significantly above 2kHz
and are not even close above 8kHz, and I don't
know which one is right. Can anyone comment on which is right?
They both come from emails to Bass List; one attributed to
Tom Danley at http://www.people.virginia.edu/%7Eedw3g/rsmeter.txt
(which now won't work for me) and the other from Michael Sims.
Both articles are attached.
Here they are compared: (add the correction to the reading
to get SPL)
Freq Danley Sims
10 +20.5
12.5 +16.5
16 +11.5
20 +6.2 +7.5
25 +4.4 +5
31.5 +3 +3
40 +2 +2.5
50 +1.3 +1.5
63 +0.8 +1.5
80 +0.5 +1.5
100 +0.3 +2
125 +0.2 +0.5
160 +0.1 -0.5
200 0 -0.5
250 0 +0.5
315 0 -0.5
400 0 0
500 0 -0.5
630 0 0
800 0 0
1000 0 0
1250 0 0
1600 +0.1 -0.5
2000 +0.2 -1.5
2500 +0.3 -1.5
3150 +0.5 -1.5
4000 +0.8 -2
5000 +1.3 -2
6300 +2 -2
8000 +3 -2
10000 +4.4 -1
12500 +6.2 +0.5
16000 +8.5 0
20000 +11.2 +1
The text with the first list refers to a treble
roll off at a pole of 10kHz, but there is no
evidence of this in Mr Sims' data.
Any help appreciated.
Grant Sellek, Adelaide, Australia
<<RS SPL meter mods.txt>> <<Re: RS SPL meter>>
- ------_=_NextPart_000_01BFCD47.BC277EE0
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name="RS SPL meter mods.txt"
Content-Transfer-Encoding: quoted-printable
Content-Disposition: attachment;
filename="RS SPL meter mods.txt"
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D
=3D =3D
=3D RS SPL METER MODIFICATIONS =3D
=3D =3D=20
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D
- - Abstract -
The analog RS SPL meter is an inexpensive instrument that can be
employed to measure the frequency response of DIY speaker
systems. Two modifications are described that improve its
accuracy at the upper and lower extremes of the audio spectrum.
- - Introduction -
The analog RS SPL meter (cat.no.33-2050) is an effective,
useful, and cheap tool that should be in every DIY speaker
builder's arsenal. When coupled with a test CD or other signal
source, accurate anechoic-like bass measurements can be
performed using this meter in a "close-miked" setup; and
in-room response can also be measured easily. =20
In many ways the analog RS meter is better than the digital
meter RS offers: The resolution of the readout is higher
(fractions of a dB, while the digital meter only reads to the
nearest dB), the analog meter movement provides more
information when analyzing dynamic signals, and finally it is
less expensive than the digital meter. If the digital meter
dispensed with the range selector switch and read fractional
dBs, I would consider purchasing one, but with it, I consider
the analog meter more useful and the better value.
The electronics of the stock analog RS SPL meter rolls off the
bass (many poles) somewhere around 35Hz, and rolls off the
treble (one pole) at 10kHz.
This is roughly comparable to the "C" weighting curve (from a
post to the bass list by Thomas Danley):
20HZ =3D6.2DB 25HZ =3D4.4DB 31.5HZ =3D3DB 40HZ =3D2DB 50 =3D1.3DB
63HZ =3D.8DB 80 HZ =3D.5DB 100HZ =3D.3DB 125HZ =3D.2DB 160 =3D.1DB
200HZ to 1250HZ Flat
1600HZ =3D .1DB 2000HZ =3D.2DB 2500HZ =3D.3DB 3150HZ =3D.5DB
4KHZ =3D.8DB 5KHZ =3D1.3DB 6.3KHZ =3D2DB 8KHZ =3D3DB 10KHZ =3D4.4DB
12.5KHZ =3D6.2DB 16KHZ =3D8.5DB 20KHZ =3D11.2DB
The frequency response mod described makes the *electronics*
flat over the entire audible range for the "C" setting of the
A/C switch. After perfoming the mod, direct meter readings
should be accurate for bass SPL measurements down to 20Hz or so
using the internal mic *without* using any correction factors
like those listed above -- in other words, pure WYSIWYG for
bass readings!
The treble response of the stock meter is another matter. The
poor "roller coaster" response of the meter in the treble
region (as seen in the instruction manual for the meter) is
caused, I think, by the physical mounting of the internal mic.
The external mic mod (coupled with the frequency response mod)
*should* correct for this if you use a Panasonic mic module
mounted in the end of some 1/4" ID brass tubing ala the MMII.
I say "should" since I haven't tested this input with a mic
yet, but have used the input to check the frequency response of
the modified electronics. Basically, if the external mic
cartridge you use has a flat frequency response, then the
modified meter electronics will be able to keep up with it and
not introduce any additional response irregularities.
Recommended external mic cartridge (excerpt from an email I got
from Mike Feldman, thanks Mike):
Panasonic electret mic capsules from Digi-Key; 1-800-344-4539.
They carry several, but I think you want WM-60AY, Digi-Key
part P9959-ND, $2.24 in quantity 1-9; $19.88/10.
This is the same cartridge used in the Mity Mike II.
Both mods are simple, don't require fundamental altering of the
meter's looks, and were free for me since I got all the parts I
needed to perform it from my junk box. Mod your meter today
and you'll be able to train a monkey to do your sub testing
tomorrow!
- --------------------------
- - FREQUENCY RESPONSE MOD -
- --------------------------
Instructions are as follows:
- - To extend the LF response: -
CHANGE (either replace or solder in parallel to the old value,
your choice, use electrolytic caps): =20
* C1, C2 from 1uF to 10uF=20
* C3, C4 from 1uF to 47uF=20
* C7 from 10uF to 220uF=20
* C8 from 100uF to 470uF=20
* C15 from 100uf to 220uF=20
* C9 from 22uF to 220uF
- - To extend the HF response: -
CHANGE (replace, use ceramic or NPO cap):
* C12 from 33pF to 12pF (controls HF response)
NOTE: In order to change the value of C12, it is necessary to
replace it, and not simply solder a 12pF in parallel with
it. It is not necessary to alter this cap if you are only
interested in good bass measurements and don't care about
the treble response of the meter, as this cap rolls off
the HF and also compensates the amplifier IC. In other
words, if you think you will not perform the external mic
mod, this capacitor can be left alone.
The easiest way to change these caps (except for C12, which
must be replaced of course) is to leave the originals on the PC
board, and solder the new caps (the values given above) to the
back of the board, where there is plenty of room. Shouldn't
take more than a half hour total if you have the parts. If you
are a stickler for neatness and can't sleep at night knowing
that the caps in your SPL meter in the next room are on the
wrong side of the board, then by all means take the extra hour
or so and actually replace them (I did, and I'm resting soundly
:-).
Case Disassembly:=20
1. Remove the two phillips head screws on the back, one
is behind the battery door.
2. Pull the back away about 1cm from the mic section. Watch
out not to crack the plastic hooks on the bottom!
3. Holding the unit so that the microphone is pointing up, pull
down on the back so that the plastic hooks on the bottom let
go. Remove the back.
4. Unscrew the two brass posts holding the pc board in position.
5. Unscrew the philips head screw on the rotary switch, remove
the phenolic wafer.
6. Remove the pc board along with the mic (with housing) and
meter. A gooey substance may fight you when you remove the
mic housing from the case.
This mod should not affect the calibration of the meter, since
only the poles in the circuits have changed, not the ac gain in
the passband. On the most sensitive settings the meter will
seem to be quite a bit jumpier. This is due to the
amplification of low frequency data such as wind and case
thumps. In fact, this is an indication that the mod is working
correctly. The breeze from a finger moving near the mic causes
the needle to move quite a bit, as does air conditioning.
After this mod, I (or the meter, rather) exhibited some
instability (hf oscillations). Increasing C12 from 10pF to
12pF cured this. If you experience similar instability (needle
jumps around, stays pegged on the lower ranges, is influenced
by the position of your hand over the needle area) increasing
C12 is the way to fix this. Be aware that the larger this cap
is, the lower the hf rolloff will be. I didn't have stability
problems before the external mic mod, however. Still haven't
tested the thing with an external mic, either, though did use
this input for the frequency response tests below.
Regardless of whether you do the external mic mod or not, after
the basic electronics mod is done, you will notice that the
meter needle pegs a couple of times at turn-on before settling
down. This is normal since the circuit now has many very long
time constants. As I stated before, on the most sensitive
settings, the meter will seem to be quite a bit jumpier. This
is due to the amplification of low frequency data such as wind
and case thumps. In fact, this is an indication that the mod
is working correctly. My meter, on the 60dB setting, registers
my moving hand from several feet away. And this isn't the
breeze from my hand "blowing" on the mic, this is my hand
moving in a rythmic closer-farther-closer motion relative to
the mic at a couple of Hz rate, Xmax ~3" p-p (sorry, ~1.5" peak
:-). It is the sensitivity of the mic cartridge to very low
bass in this test that lead me to believe the cartridge is
probably pretty flat to a few Hz.
I just want everyone who is contemplating performing this mod
on their meter (the frequency response correction mod, with or
without the external mic mod) to be well aware of the behavior
afterward. I am quite happy with the results, but if this sort
of behavior (i.e. the double pegging and settling at turn-on)
drives you crazy, perhaps you should decide against surgery and
go with the old therapy, i.e. equalization charts.
The SPL meter electronics (including the meter needle itself)
now respond in the following way (regardless of the range
switch, external mic input, C12=3D12pF):
"Fast" response switch position:
+/-3dB: 6Hz to 50kHz
+/-1dB: 28Hz to 23kHz
- -1.2dB @ 20Hz
- -0.8dB @ 20kHz
Flat otherwise.
"Slow" response switch position:
+/-3dB: 4Hz to 50kHz
+/-1dB: 8Hz to 23kHz
- -0.2dB @ 20Hz
- -0.8dB @ 20kHz
Flat otherwise.
The "Slow" response setting looks like the way to go for
accurate low bass measurements. Based on the -0.2dB @ 20Hz
figure, we can now pretty much ignore the frequency response of
the electronics for most bass measurements.
- ----------------------
- - EXTERNAL MIC MOD I -
- ----------------------
Basically, this mod turns the A/C switch into an
external/internal mic selector, and turns the OUTPUT jack on
the side of the meter into an input for an external fet preamp
cartridge-type mic. The meter supplies the power to the
external mic and no preamp is necessary.
Remove R11 (10k), R17 (15k), C14 (0.1uF), C4 (now 47uF), and C5
(1uF). Put R17, C14, and C5 in your junk box. Jumper C9 (now
220uF) to R18 (75 ohms) at the switch. Observing polarity,
solder C4 where R11 used to be, then solder one side of R11 in
a PC board hole that connects the positive side of C4 to R11.
This just changes the order of these two components, making it
easier to solder a jumper to the series connection of them (to
the end of R11 rather than to the positive side of C4). Remove
the end of the jumper wire that used to go to the negative side
of C4 (it comes from the resistive divider tap at the wafer
switch) and solder it to the free end of R11. Now a SPDT
section of the A/C switch has been freed up. Solder a jumper
wire from the inner conductor of the RCA jack to the now free
"A" side of the switch (you can use the holes in the board
where R17 and C14 were). Run a jumper wire from the
intersection of R26 (3.3k) and C1 (now 10uF) and connect it to
the center terminal of the now free side of the switch. Lift
the left mic cartridge terminal (+) from the pc board and run a
jumper wire from it to the "C" side of the switch. Use some
heat shrink tubing to keep this connection from touching the PC
board (no need to actualy shrink it, though). All done.
- -----------------------
- - EXTERNAL MIC MOD II -
- -----------------------
Instead of gutting the A/C switch, install a 1/8" switching
phone jack on the side of the case and use it to switch between
the internal and external mic. A/C weighting will be
preserved, as will be the mic output. This mod is simpler, and
preserves the basic functioning of the meter. I recommend it
over the EXTERNAL MIC MOD I above.
- ---------------
- - FAQ SECTION -
- ---------------
> A Quick Question
>
> You indicated you left the caps on & attached caps to back of board =
meaning
> you, in case of first cap change, added 9uF to back inparallel or =
cust lead
> on one on front & added a 10uF
>
> also, I assume I would match the type of caps ie. electrolytic, =
tantulum,
> mica etc....
>
> I have a 'basic' understanding of electronics at best
The idea is only to lower the poles so that they do not
significantly alter the meter response at the frequencies of
interest (>10Hz or so). So it is really just a matter of
increasing the capacitance of C1, C2, C3, C4, C7, C8, C9, and
C15 until this condition is true.
There is no need to remove the original caps, and no need to
find special values to make the resulting parallel capacitance
values exact. For example, soldering a 10uF in parallel with a
1uF only makes the resulting value off by 10%, and this is
usually within the tolerance of the 10uF in the first place!
The resulting pole may be 10% lower, but all the better. If
you use values that are significantly larger than those that I
specifiy for the signal path, the meter will take a lot longer
to settle down at turn-on, which might drive your crazy if you
are sensitive to such things. Mine takes about 3-5 seconds to
calm down after turn-on, and is stable during and after
changing the range switch. It is very sensitive to wind and
case shock after the mod, which makes sense if you think about
it.
C12 is the only capacitor that needs to be replaced, since its
value has to be reduced.
I don't know if you caught it or not, but my external mic mod
changed C12 (33pF originally) from 10pF to 12pF for stability.
This capacitor controls the high frequency roll-off of the
meter (33pF makes the meter roll off at 10kHz) and also keeps
the cheesy op amp (a precursor to the 741, or so I am told) from
oscillating. If you find that your meter is unstable after the
mod (needle moves erratically, pegs on the lower ranges, stays
somewhere in the midrange even with no sound input), try adding
small values of capacitance (2pF or so) across C12 until the
meter stabilizes. This will make your meter less accurate in
the high-end (the high-end response will start rolling off
sooner). This is not so much of a problem if you don't use an
external mic, since the internal mic has a sleazy high-end
response anyway (probably more due to how the mic cartridge is
mounted than anything else). Better to err on the side of
stability, since the meter is useless if it is not stable.
Use electrolytics in parallel with the electrolytics (which is
every modified cap except C12). I used some that I scrounged
from an old VCR. These caps were very small for their size,
making them an easy fit. Any voltage level at or above 10V is
fine. Observe polarity when installing them (s/b same as the
originals).
A ceramic or NPO will do for C12. R/S sells an assortment of
small value caps (1-30pF) that will do nicely for C12, and will
allow you to find the critical value that will yield both
stability and maximum flat hf response. As I stated above,
starting with 12pF would probably be wise.
> You had previously written :
>=20
> > The easiest way to change these caps (except for c12, which
> > must be replaced) is to leave the originals on the PC board,
> > and solder the new caps to the back of the board, where there
> > is plenty of room.=20
>=20
> I assume from the above that you meant to add the new parts=20
> to the old ones (in parallel). So C1 goes from 1 uF to 11 uF
> not to 10 uF. This looks safe enough since you're just lowering
> the pole frequency even more than if the old cap were removed.
Right. The tolerance on electrolytics is usually rather wide,
and all we are trying to do is lower the poles below some
(rather arbitrary) frequency.
> -2-
> I got a little confused with your description of the external=20
> mic wiring. Just to make sure I understand what you did, here's
> my take on it, let me know if I have it wrong :
>=20
> - Use the output RCA jack as the external mic input by removing
> R17.
>=20
> - Get rid of the A/C weigh feature. Make everything effectively
> "C" weighed by nuking C5 and shorting C9 to R18. Then somehow
> keep C4 and R11 electrically the same but bypass the switch.
>=20
> - Now use the A/C weigh switch to select between the internal
> and external mic.
>=20
> Is that it ? My main confusion is with the description of=20
> C4/R11. I didn't see any mention of connecting C4 or R11
> (depending on the order placed) back to the rotary switch
> (center on the A/C switch. Anyway, if I know what you intended
> to do, it's a simple matter to just do it.
You have it right. It is probably easier just to do it than to
decipher my instructions. I used the top section of the A/C
switch for external/internal selection. I switched the
positions of C4/R11 since this made running the wire from the
rotary switch to the series combination easier (it now goes to
one end of R11 hanging off the board). In retrospect, I might
go back and hook the A weighting stuff back in and use a
separate dedicated jack (1/8" switching jack, like for
earphones) for the external mic input. This would cause
automatic switching when an external mic is plugged in and
preserves the A weighting and external mic out. The wiring
would also be simpler. You may want to consider this.
> FYI, I made the meter mods last night - just the 9 caps.
> So far as i can tell, it's acting as you described. The needle
> jumps a lot on power-up and when changing ranges, especially in=20
> "fast" mode. Hand motion is detectable. Next step is to=20
> run some tests on it and compare it to previous results.
>=20
> Also, I think I'll keep it as an internal mic device only if
> the existing mic module seems to be pretty sensitive. It's probably
> not flat all the way to DC, but there's a decent chance it's
> flat to at least 20 (the Panasonic module I bought from DigiKey is=20
> supposed to be rated 20-20k; I wonder how far off it is below
> that ?) and that's good enough for me. Then I'll use the other mic=20
> for something else I guess.
Mine pegs twice on power-up, but then settles down. Switching
ranges doesn't affect it very much when in the "slow" mode,
which is where mine stays now.
Note that the "slow" setting will give much better low
frequency readings, -0.2dB @ 20Hz vs. the "fast" setting
response of -1.2dB @ 20Hz. This also keeps the needle from
jumping around so much during range switching.
I guess you changed high frequency cap C12 also. Did you make
it 10pF or 12pF? I had to go to 12pF for stability reasons,
outlined in my second post. If *holding* your hand near the
meter area causes readings, you have oscillation and should
increase C12 until they go away.
Adding the external mic option would be a snap using a 1/8"
phone jack that switches. Have you considered this? I think
the only reason the HF response sucks so bad (in the RS manual,
the roller coaster action in the highs) is due to the funky
mounting of the internal mic. That huge plastic flange (I
thought it was aluminum until I took the thing apart; some
things I would rather not know :-) and that funky "PC board"
screen *have* to be altering the response curve in a major
way. An external mic (like the wand-type MMII cartridge at the
end of a tube type thing - without all the fancy electronics)
would make this unit accurate all the way up to 20kHz, where
the response of the electronics is down only -0.8dB (with
C12=3D12pF). Getting my body out of the measurement area and the
meter nearer to my eye would be added bonuses (boni?). I
really need to buy some of those Panasonic mics.
HF response aside, I bet dollars to donuts that the mic
cartridge itself is, as you say, flat to at least 20Hz based on
the "waving ~3Hz hand" experiment. Be nice to have some way to
check this. All we need is a calibrated sub good to 3Hz (next
project...just kidding). Till then, I'll trust that the bass
readings I get are fairly accurate.
> Just to clarify, am I correct in assuming that this mod will
> correct the deficiencies of the internal mike, but that the
> impact of C/A weighting will still have to be cranked in the
> the readings?
Just the opposite. The electronics in the stock meter rolls
off the bass (many poles) somewhere around 35Hz, and rolls off
the treble (one pole) at 10kHz. =20
The internal mic seems to be fine for bass readings, and
continues to work well for those situations when you need
calibrated "A" weighting readings (rock concerts and jet planes
and such) if you use external mic mod II. I am disinclined to
change the external appearance of the meter, especially since
the external mic mod *should* so easily get around the high-end
response problem, and also will get my body out of the
measurement field and place the meter nearer to my eyes where I
can more closely scrutinize the trembling quiver of its wee
little needle.=20
- ------_=_NextPart_000_01BFCD47.BC277EE0
Content-Type: message/rfc822
Content-Description: Re: RS SPL meter
Message-ID: <806B2E93840FD211922E0008C7288DDC01448C8E@sagemst0003.roads.sa.gov.au>
From: Michael Sims <m-sims1@uiuc.edu>
Reply-To: m-sims1@uiuc.edu
To: Bass List <bass@mcfeeley.cc.utexas.edu>
Subject: Re: RS SPL meter
Date: Sun, 16 May 1999 02:22:51 +0930
Importance: high
X-Priority: 1
MIME-Version: 1.0
X-Mailer: Internet Mail Service (5.5.2448.0)
Content-Type: text/plain;
charset="iso-8859-1"
ncarver@execpc.com wrote:
> I was all set to perform the mods myself, but it made more sense to use it
> as is and then adjust the results using the numbers Michael Sims (I think)
> provided a few months back. Maybe Michael could repost to save you the
> work.
Here it is!
First, I would like to thank Eric Busch (The DUMAX technician)
and Dave Clark from DLC Design for the low frequency data,
Tom Nousaine for supervising the calibration, Bill Duddleston
at Legacy Sound in Springfield, IL for letting PSACS meet at
his business, and Paul Barton from PSB for furnishing the
loudspeaker calibrated at the NRC anechoic chamber in Canada.
The Radio Shack meter is a wonderful unit. About a two and a half years
ago, I did a calibration curve for the RS meter using lab equipment,
with
Eric Busch from DLC Design adding the low bass
down to 10 Hz. This was published in PSACS Sound Bytes in two issues.
These are the corrections that should be added to the meter readout in
order to achieve the correct SPL. These corrections are only valid
for the meter set to C weighting, using 1/3 octave pink noise (easily
available from various CDs), with the mic pointed at the speaker.
Both my analog meters and my digital meter measured the same
in October, 1996.
These are corrections, they are to be added to the meter readout for the
correct response in dB SPL.
10Hz +20.5
12.5Hz +16.5
16Hz +11.5
20Hz +7.5
25Hz +5
31.5Hz +3
40Hz +2.5
50Hz +1.5
63Hz +1.5
80Hz +1.5
100Hz +2
125Hz +0.5
160Hz -0.5
200Hz -0.5
250Hz +0.5
315Hz -0.5
400Hz 0
500Hz -0.5
630Hz 0
800Hz 0
1KHz 0
1.25Khz 0
1.6KHz -0.5
2Khz -1.5
2.5Khz -1.5
3.15Khz -1.5
4KHz -2
5KHz -2
6.3KHz -2
8KHz -2
10Khz -1
12.5KHz +0.5
16KHz 0
20KHz +1
To measure the in-room response of your speakers with the SLM,
find
a quiet and undistracted time, obtain a 1/3 octave pink noise CD, mic
stand, and worksheet. With the speakers in their normal positions and
using a mic stand for the SLM (I've had good results
just holding the meter
too,
pink noise is forgiving), place its microphone where your ear would be
at your favorite position or "sweet spot". Set the meter to "C" and
"slow". Play the 1 Khz, 1/3 octave pink band and set
the level on the amp or preamp, and the meter range, so the meter reads
80 dB at 0 dB on the meter. Higher levels might cause driver
compression
in the frequency extremes, rolling off the response. Now go back to the
first ISO center 1/3 octave band on your CD (25 Hz on mine) and record
the response: 3.5, or -1.0 , or -5.0, or whatever
it is. Now step through the pink noise
bands, recording the meter level each time. This is the raw data.
Keeping the meter in the same measuring position, using an accurate
CD, having a quiet room, repeating the measurements for accuracy,
understanding what you are measuring, fresh batteries, not talking
while measuring, having your meter calibrated for overall level
(relative level comparison is unaffected), and doing only one
speaker at a time if possible to avoid comb
filtering (variations of plus or minus 2 dB are possible) are all
important factors. Sometimes if I have
to measure two speakers at a time, I move the meter around in a figure
eight pattern, slowly, and try to obtain an average reading, as the
microphone moves in and out of the combing peaks and troughs. Best
accuracy would be obtained from taking several measurements at different
listening positions, if one has the time and patience.
Now take the raw data and make the corrections on the work sheet,
entering the new values in the appropriate column. Time to either moan
or marvel, since this is the actual in-room 1/3 octave
pink noise frequency response of your speaker/system at that listening
position. Plotting the results on graph paper in different colors for
left, right, center, etc. makes it look cool.
Yes, this way is tedious, but it is very inexpensive. And very
accurate. For the third octave pink noise, I use Carver's Amazing
Bytes CD, GRP Z-9907; other CD's with 1/3
octave pink noise ISO centers are:
My Disc, Sheffield 10045-2-T
Sheffield/Coustic Test and Demonstration Disc, Sheffield 10040-2
Autosound 2000 CD #103, $18, 800-795-1830
IASCA Setup and Test CD
HI-FI News and Record Review "CD-II", $30
Japan Audio Society Audio Test CD-1, YDDS-2
- --- these last two available from DB Systems, 603-899-6415.
For the others:
http://www.audioxpress.com/
http://www.mcmelectronics.com/main.html
http://www.parts-express.com/
There are other CD's that have warble tones on them, but I am not
comfortable using them. I also extensively use track 19, disc 2,
from Delos "Surround Spectacular", DE 3179.
This has a slow sine sweep from 160Hz to 20Hz with the voice of
David Ranada announcing the frequencies as they
descend. A fantastic help when used with the Radio Shack SLM, you can
easily tell where the room peaks and dips are.
http://www.delosmus.com/
You have permission to copy and distribute this information freely, as
long as no commercial gain is involved.
Radio Shack is your friend.
Here is how I did my calibration:
The $34.99 Radio Shack 33-2050 analog sound level meter has been
around for over 25 years. Its predecessor, the 33-1028, was reviewed
favorably in Stereo Review, (Julian Hirsch, "Equipment Test Reports",
Stereo
Review, August 1972). It has a much different curve than the ones I
tested.
To verify the accuracy of the newer version, I compared it to an
Audio Control 3050 RTA, the same one Tom Nousaine used for years in his
test reports for Car Stereo Review until he bought MLSSA. The overall
SPL accuracy of all three of my Radio Shack sound level meters -- 2
analog
and 1 digital 33- 2055-- were within 1 dB of 75 dBC SPL compared to the
Audio Control. I then checked the frequency response, comparing it
while
set to C weighting and slow, with pink noise, 1/3 octave band by 1/3
octave
band, to the Audio Control RTA in the SPL mode. Using the same official
PSACS calibrated PSB loudspeaker and a pink noise CD, I made a
calibration curve that can be subtracted from the results obtained by
the
Radio Shack in your living room to obtain accurate, repeatable
measurements
for about $60, including pink noise CD. Make sure your meter is set to
C
weighting. The digital meter and my second analog meter (6 years
newer than the test unit in 1996) were the same as the test SLM.
Response below 25 Hz done by Eric Busch with sine waves and
B&K equipment at Dave Clark's DLC Design in Michigan.
Michael Sims
Prairie State Audio Construction Society
>
- ------_=_NextPart_000_01BFCD47.BC277EE0--
=========================================================================
From: Thomas Danley <Tom@ppci.com>
Subject: Re: [JN] Radioshack SPL meter correction curves -I have two versions
Date: Fri, 02 Jun 2000 19:58:15 -0500
Source: Sound Digest Archive v02.n563
"Sellek, Grant (TSA)" wrote:
> Hi all, I have two sets of "correction tables" for my analog
> Radioshack SPL meter. They deviate significantly above 2kHz
> and are not even close above 8kHz, and I don't
> know which one is right. Can anyone comment on which is right?
> They both come from emails to Bass List; one attributed to
> Tom Danley at http://www.people.virginia.edu/%7Eedw3g/rsmeter.txt
> (which now won't work for me) and the other from Michael Sims.
> Both articles are attached.
>
> Here they are compared: (add the correction to the reading
> to get SPL)
>
> Freq Danley Sims
> 10 +20.5
> 12.5 +16.5
> 16 +11.5
> 20 +6.2 +7.5
> 25 +4.4 +5
> 31.5 +3 +3
> 40 +2 +2.5
> 50 +1.3 +1.5
> 63 +0.8 +1.5
> 80 +0.5 +1.5
> 100 +0.3 +2
> 125 +0.2 +0.5
> 160 +0.1 -0.5
> 200 0 -0.5
> 250 0 +0.5
>