Sound Practices Mailing List Files - Volume 1
=========================================================================
From: Steve Van Osdell <svanos@toast.net>
Subject: 600V Coupling Caps question
Date: Thu, 01 Jan 1998 21:19:45 -0600
Source: Sound Digest Archive v01.n148
Again on the subject of that little Knight 6BQ5 integrated...
I notice that the coupling caps are .047 at 600V. Any idea why the voltage
rating is so high on these? Seems like to me that 400V should work fine.
The reason I'm asking is that I have some 400V caps of this value, but no
600's.
Thanks Steve
=========================================================================
From: "Mills, Anthony" <anthony.mills@deo.defence.gov.au>
Subject: 600V Valve Workbench Power Supply (unclassified)
Date: Thu, 29 Oct 1998 10:06:07 +1100
Source: Sound Digest Archive v01.n473
Joes
I was hoping that someone would have some schematics for a valve based
variable power supply. I wanted up to 600V / 200mA output. I have the
Sound Practices schematic for the Kepco supply (a little too complex).
I like the idea of an all valve shunt regulator using some of those
Svetlana triodes.
I have a number of components 900V caps, 10H chokes, heaps of 811-3
triodes lying around and figured that these could be gainfully employed
instead of gaining dust. I'm not looking for "state of the valve art"
performance but something that will provide good regulation performance.
Also, if anyone with good knowledge on these things that would be
interested in providing some advice if needed.
Thanks in advance.
Regards
=========================================================================
From: "Alfia Mak" <alfiamak@hkstar.com>
Subject: 6014/C1K data wanted
Date: Mon, 30 Nov 1998 01:14:25 +0800
Source: Sound Digest Archive v01.n508
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Hi All,
I got a pair of the 6014/C1K from Ebay, can anyone advise where I can =
find data on this tube ? What kind of application I can use this tube =
for ?
Thanks, Alfia
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<DIV><FONT color=3D#000000 face=3DArial size=3D2>Hi All,</FONT></DIV>
<DIV><FONT color=3D#000000 face=3DArial size=3D2>I got a pair of the =
6014/C1K from=20
Ebay, can anyone advise where I can find data on this tube ? What kind =
of=20
application I can use this tube for ?</FONT></DIV>
<DIV><FONT color=3D#000000 face=3DArial size=3D2></FONT> </DIV>
<DIV><FONT color=3D#000000 face=3DArial size=3D2>Thanks,=20
Alfia</FONT></DIV></BODY></HTML>
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From: "Alfia Mak" <alfiamak@hkstar.com>
Subject: 6014/CIK tube
Date: Sat, 28 Nov 1998 21:50:31 +0800
Source: Sound Digest Archive v01.n507
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Anyone has data on the 6014/CIK tube ?
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<DIV><FONT color=3D#000000 face=3DArial size=3D2>Anyone has data on the =
6014/CIK tube=20
?</FONT></DIV></BODY></HTML>
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=========================================================================
From: Roscoe Primrose <roscoe@aiko.com>
Subject: 601C Tweeter buzz...
Date: Wed, 28 Oct 1998 12:22:20 -0500
Source: Sound Digest Archive v01.n472
Well, I finally got the mini Onkens up last night. However, at moderate
and higher volumes, there's a slight buzz from one of the tweeters...
Anyone have any idea how to correct it?
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: Ed Johnson <rb1304@alltel.net>
Subject: 604E
Date: Wed, 01 Oct 1997 19:42:37 -0400
Source: Sound Digest Archive v01.n051
Does anyone have any info on what a good enclosure for the altec 604E
speaker.What about an 816A cab,or A7.Any Idea?
=========================================================================
From: "GREGORY MONFORT" <WINGRACER@classic.msn.com>
Subject: RE: 604E
Date: Thu, 2 Oct 97 04:23:41 UT
Source: Sound Digest Archive v01.n054
I've never seen/heard one in a horn, but I believe you will have too much
beaming for good imaging assuming you have two. I imagine there are other
problems or Altec would have offered this combo. An 816 won't have enough back
volume for good LF extension plus you will need to put damping material on the
horns parallel surfaces to prevent standing waves thus reducing horn loading
to some extent. A7's won't have these problems.
The home version cabinet (model 861) was about 3.5 cuft with (2) 3" dia. x
3/4" vents. F3 was about 50 hz. A 6 cuft version (model 855a) with a 2" x 10"
x 3/4" slot vent had an F3 of about 35 hz. Obviously, you need to measure the
driver(s) to accurately calculate a box.
GM
- ----------
Does anyone have any info on what a good enclosure for the altec 604E
speaker.What about an 816A cab,or A7.Any Idea?
=========================================================================
From: "Anthony J. Knettel" <AKnettel@CompuServe.com>
Subject: 6072-5687 Williamson amps
Date: Fri, 26 Sep 1997 10:28:23 -0400
Source: Sound Digest Archive v01.n044
>Lynno wrote:
>[...snip...]
>(By the way, the same article suggests a 6072 for the front end of
>the Williamson, and a 5687 for the driver - wonder if this is where
>Atarashi & Kondo first discovered the 6072/5687 combo?)
>[...snip...]
Has anyone tried this combination? There was a rec.audio.tubes
thread last week on replacing the 12AU7 driver in a Heath W5 with
a 5687, and after perusing an Audio Note circuit pack I already had
the 6072-5687 combo on my mind. Whether by accident or design
I've accumulated several Williamson amps by now, but so far only
diddled with replacing the ubiquitous 12AU7s (not one of my fave
tubes) with 6CG7s and the like....
Anthony (AKnettel@compuserve.com)
=========================================================================
From: Grover Gardner <groverg@postoffice.att.net>
Subject: Re: 6.3V rectifiers, was RE: Filament supplies
Date: Sat, 17 Oct 1998 09:55:30 -0500
Source: Sound Digest Archive v01.n457
At 11:38 AM +0930 10/17/98, Sellek, Grant (TSA) wrote:
>Much appreciated, Paul.
>
>Is the 6AL5 Imax correct at 18mA? If so, it is strange that the perveance is
>specified at 60mA!
>
>I am not sure what the column "cath'd?" means.
>
>max_VAC seems generally very low on these. My preamp trannies put out
>840VCT, which I want to rectify and choke input to a 380VDC rail, less
>losses in the rectifier and chokes. None of these full wave rectifiers come
>close! Or am I mis-reading the data? If not, what is a useful rectifier
>(preferably 6.3V)?
Cath'd refers to the cathode status--directly or indirectly heated, shared
or separate in a dual diode or full-wave rectifier.
An indirectly heated cathode will have limited heater-cathode voltages.
For a damper, you can use them as forward diodes with usually no
problem--most of them have -500V+ ratings, but for reverse use, as in a
bridge, a diode might see a positive heater-cathode voltage, and many are
limited to +300V or less.
A directly heated diode, like a directly-heated triode, has no such limits.
The max AC ratings usually mean "per plate"--for instance a 5U4 has a 750V
max limit per plate, which means you could use it with a 1500VCT tranny.
You tranny would supply 420vac per plate, so you are going to run into some
problems with some of the small full-wave rectifiers Paul lists. However,
I *believe* you would be fine with a pair of damper tubes.
Which brings up a good point, actually--most of the damper specs give a
maximum continuous current rating but not a *continous max plate
voltage*--should this be a concern?
Grover Gardner
groverg@postoffice.att.net
=========================================================================
From: "Sellek, Grant (TSA)" <Grant.Sellek@roads.sa.gov.au>
Subject: 6.3V rectifiers, was RE: Filament supplies
Date: Sat, 17 Oct 1998 11:38:16 +0930
Source: Sound Digest Archive v01.n457
Much appreciated, Paul.
Is the 6AL5 Imax correct at 18mA? If so, it is strange that the perveance is
specified at 60mA!
I am not sure what the column "cath'd?" means.
max_VAC seems generally very low on these. My preamp trannies put out
840VCT, which I want to rectify and choke input to a 380VDC rail, less
losses in the rectifier and chokes. None of these full wave rectifiers come
close! Or am I mis-reading the data? If not, what is a useful rectifier
(preferably 6.3V)?
Grant
> ----------
> From: Paul Joppa[SMTP:pdj@ISDNseattle.net]
>
> Here's a list, extracted from teh GE tube manual (I did this a while
> back - must have been bored!)
>
> 6.3-volt full-wave rectifier tubes
>
> type current cath'd? max_I I..@.. Vdrop max_VAC base
>
> 6AL5 0.3A sep't x2 18mA 60mA 10v 117v 7-pin
> mini
> 6AX5 1.2A separate 125mA 125mA 50v 350v octal
> 6AX6 2.5A sep't x2 250mA 250mA 21v 350v octal
> 6AZ6 0.15A sep't x2 20mA 8mA 3.5v 200v octal
> 6BW4 0.9A separate 100mA 100mA 40v 325v 9-pin
> mini
> 6BY5-G 1.6A sep't x2 175mA 175mA 32v 375v octal
> 6CA4 1.0A separate 150mA 150mA --- (1000pk) 9-pin
> mini
> 6W5-G 0.9A separate 90mA 90mA 24v 325v octal
> 6X4 0.6A separate 90mA 70mA 22v 360v 7-pin
> mini
> 6X5 0.6A separate 80mA 70mA 22v 360v octal
> 6Z5 12.6CT 0.4A separate 60mA ---- --- (1500pk) 6 pin
> 6ZY5 0.3A separate 40mA 40mA 18v 325v octal
> 5852 1.2A separate 65mA ---- --- 300v octal
>
> > I know there are 6.3V damper diodes like the 6CJ3,....
>
> The big deal about damper diodes is high perveance. Looking at the
> I..@..Vdrop columns above, perveance is I/(Vdrop^3/2) (the denominator
> is Vdrop to the 1.5 power in case my notation is unclear!). 6AX6 is
> the best on this list, but 6X4/5, 6W5, and 6BY5-G are candidates. 6CA4
> is pretty high though I haven't found ratings, but it's getting
> expensive and harder to find.
=========================================================================
From: Paul Joppa <pdj@ISDNseattle.net>
Subject: Re: 6.3V rectifiers, was RE: Filament supplies
Date: Sun, 18 Oct 1998 16:13:06 -0700
Source: Sound Digest Archive v01.n458
All-
Sorry, my headings were not as clear as I thought.
current = filament current
cath'd? = cathode type - separate (not direct-heated);
...x2 = two separate cathodes (not shared between two plates)
max_I = maximum rated average current, both plates (typical PS)
I..@..Vdrop = current and voltage drop at that current
max_VAC = maximum AC voltage per plate
Note that these are just the summary specs in my GE manual, except
where I may have misread something.
- -Paul Joppa
=========================================================================
From: Paul Joppa <pdj@ISDNseattle.net>
Subject: Re: 6.3V rectifiers, was RE: Filament supplies
Date: Sun, 18 Oct 1998 16:18:01 -0700
Source: Sound Digest Archive v01.n458
Grover Gardner wrote:
> ...snip...
> The max AC ratings usually mean "per plate"--for instance a 5U4 has a 750V
> max limit per plate, which means you could use it with a 1500VCT tranny.
...snip...
fwiw, my GE manual lists 450v/plate for the 5U4, or 900vCT.
- -Paul Joppa
=========================================================================
From: Grover Gardner <groverg@postoffice.att.net>
Subject: Re: 6.3V rectifiers, was RE: Filament supplies
Date: Sun, 18 Oct 1998 22:36:29 -0500
Source: Sound Digest Archive v01.n458
At 4:18 PM -0700 10/18/98, Paul Joppa wrote:
>Grover Gardner wrote:
>> ...snip...
>> The max AC ratings usually mean "per plate"--for instance a 5U4 has a 750V
>> max limit per plate, which means you could use it with a 1500VCT tranny.
>...snip...
>
>fwiw, my GE manual lists 450v/plate for the 5U4, or 900vCT.
Yes, thank you, I pulled the number out of the air without thinking :-)
Grover Gardner
groverg@postoffice.att.net
=========================================================================
From: "Daniel J. Marshall" <danmarshall@worldnet.att.net>
Subject: 6A3 settings for Jackson 648
Date: Wed, 11 Nov 1998 11:56:33 -0800
Source: Sound Digest Archive v01.n487
Hi All,
Say, does anyone have a Jackson 648 tube tester? If so, could you
please email me the settings for 6A3 tubes (or 2A3). I have 7 NOS
pieces I am planning to offer for sale, but would like to test and match
them up in quads or pairs first. I have the supplement book somewhere,
but it inadvertently got packed in another box and apparently is in
storage. Thanks.
Dan Marshall
=========================================================================
From: Tim Reese <reese@nmr.MGH.harvard.EDU>
Subject: Re: 6A3 vs 2A3
Date: Thu, 25 Jun 1998 09:22:59 -0400 (EDT)
Source: Sound Digest Archive v01.n319
Harry Pitaro wrote
>I was fortunate enough to find a couple of NIB 6A3's at a ham fest for
>$0.50 each! My manual tells me that they are identical to the 2A3 except
>in heather voltages. Anybody tried them? What do they sound like?
I asked sort-of the same question re my Brook 12A clone. The 6A3 is a 6.3V
filament 2A3. Response to my question confirmed that the 6A3 is a fine
sounding tube - sonically almost identical to the 2A3. Other similar tubes
are the 6A5 (6A3 with an indirectly heated cathode, slightly brighter
sound than 6A3) and the 6B4G, an octal 6A3. Most of the discussion
centered on the hum characteristics of 2.5V vs. 6.3V heaters, with this
issue likely moot in a PP configuration like the 12A (hum cancels). Lower
filament voltage means less hum from AC heated filaments.
Joe has used SE 6A5s with great success, as recounted in the latest SP.
Wow, $0.50... is that AUD or USD? cheers tr
- ----------------------------------------------------------------------
Tim Reese, MGH NMR Center reese@nmr.MGH.harvard.edu
=========================================================================
From: pitaro@ozemail.com.au
Subject: 6A3 vs 2A3
Date: Thu, 25 Jun 1998 18:06:23 EST
Source: Sound Digest Archive v01.n319
Hi all,
I was fortunate enough to find a couple of NIB 6A3's at a ham fest for
$0.50 each! My manual tells me that they are identical to the 2A3 except
in heather voltages. Anybody tried them? What do they sound like?
Regards,
Harry Pitaro
+-----------------------+---------------------------------------------+
| Melbourne, Australia | A good discussion is like a miniskirt; |
| | Short enough to retain interest |
| pitaro@ozemail.com.au | and long enough to cover the subject. |
+-----------------------+---------------------------------------------+
=========================================================================
From: Grover Gardner <groverg@postoffice.att.net>
Subject: Re: 6A3 vs 2A3
Date: Thu, 25 Jun 1998 09:48:30 -0500
Source: Sound Digest Archive v01.n320
At 9:22 AM -0400 6/25/98, Tim Reese wrote:
>Harry Pitaro wrote
>>I was fortunate enough to find a couple of NIB 6A3's at a ham fest for
>>$0.50 each! My manual tells me that they are identical to the 2A3 except
>>in heather voltages. Anybody tried them? What do they sound like?
>
>I asked sort-of the same question re my Brook 12A clone. The 6A3 is a 6.3V
>filament 2A3. Response to my question confirmed that the 6A3 is a fine
>sounding tube - sonically almost identical to the 2A3. Other similar tubes
>are the 6A5 (6A3 with an indirectly heated cathode, slightly brighter
>sound than 6A3) and the 6B4G, an octal 6A3. Most of the discussion
>centered on the hum characteristics of 2.5V vs. 6.3V heaters, with this
>issue likely moot in a PP configuration like the 12A (hum cancels). Lower
>filament voltage means less hum from AC heated filaments.
>
>Joe has used SE 6A5s with great success, as recounted in the latest SP.
My findings correspond with Tim's--the 6 volt versions of the 2A3 are very
good-sounding, and the 6A5G is a real sleeper--a bit brighter as Tim says
but this can be adjusted with some careful parts selection, and of course
the extra quiet is a real bonus. So these are in the latest SP, huh?
Guess they'll be harder to find, now :-)
Grover Gardner
groverg@postoffice.att.net
=========================================================================
From: Roscoe Primrose <roscoe@aiko.com>
Subject: Re: 6A3 vs 2A3
Date: Thu, 25 Jun 1998 09:51:37 -0400
Source: Sound Digest Archive v01.n320
pitaro@ozemail.com.au wrote:
>
> Hi all,
>
> I was fortunate enough to find a couple of NIB 6A3's at a ham fest for
> $0.50 each! My manual tells me that they are identical to the 2A3 except
> in heather voltages. Anybody tried them? What do they sound like?
Killer bargain! They sound like 2A3s, except hum can be more of a
problem...
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: Ron Bales <rbales@gte.net>
Subject: Re: 6A3 vs 2A3
Date: Thu, 25 Jun 1998 13:38:11 -0400
Source: Sound Digest Archive v01.n320
Harry Pitaro wrote
>I was fortunate enough to find a couple of NIB 6A3's at a ham fest for
>$0.50 each! My manual tells me that they are identical to the 2A3 except
>in heather voltages. Anybody tried them? What do they sound like?
>
6A3's are good. There are greater differences among 2A3's than there is
between 2A3 and 6A3 in gweneral. The 6A3's higher filament voltage will
tend to produce more hum, or at least there is more potential (nudge,
nudge) for hum. This wasn't a problem in my SE monoblocks.
ROn
=========================================================================
From: pitaro@ozemail.com.au
Subject: 6A3 vs 2A3
Date: Sat, 27 Jun 1998 18:13:06 EST
Source: Sound Digest Archive v01.n323
Hi Guys,
Thanks for the info. Seems like I picked up a couple of bargains.
Regards,
Harry Pitaro
+-----------------------+---------------------------------------------+
| Melbourne, Australia | A good discussion is like a miniskirt; |
| | Short enough to retain interest |
| pitaro@ozemail.com.au | and long enough to cover the subject. |
+-----------------------+---------------------------------------------+
=========================================================================
From: "=?ISO-8859-1?Q?Torbj=F8rn_Lien?=" <mdrivekl@online.no>
Subject: Re: 6AS7 alternate use....
Date: Mon, 7 Dec 1998 06:38:01 +0100
Source: Sound Digest Archive v01.n523
Hmm,-
I've been thinking of a way to put these too way off
6AS7's to use.Would be a shame just to throw away...
(Ohwell,-could always be traded away to wayoff6AS7
collectors??!!,- :)
How 'bout strapping theire grids via afew 100 ohms
to the anodes? I bet that would make some real nice
cheap rectifiers.....
Anyone tried it?
Or,-one could strap the grids to the cathodes...
But then one have the option to put some current
sensing circuit between the cathode and the grid...
Or,-! What about a CCS? Would make a sneaky
circuit that puts a limit to the current-pulses
to the first PSU-Cap..
Wouldn't this work as a "rectifier with input choke
emulator"?
It certainly would be possible to use mains-xformers
with rather high AC-voltages compared to DC-out...
Wouldn't this ensure charging of the input-cap over
a much longer time on each cycle...reducing 1.Cap
ripple and peak-currents?,-.....
Torbjoern Lien
>
>
>
>
- -
=========================================================================
From: trs@carlsmith.com
Subject: Re: 6AS7 Balance (was More PP 6B4 thoughts)
Date: Fri, 4 Dec 1998 10:48:38 -1000
Source: Sound Digest Archive v01.n519
Yeow! I picked up a bunch of these to use in either Dan N.'s
cathode-driven SE amp or the one by Cy Brenneman at the
Svetlana website. I know you guys are talking PP here, but
a 71 mA imbalance between two halves of the same tube is
scary. Should I sort for closer balance in an SE application?
And aren't the 6080s supposed to be better, not worse, than
plain-vanilla 6AS7s?
Thanks, Tom Sylvester trs@carlsmith.com
>>> "pdj@ISDNseattle.net" 12/04/98 10:15am >>>
Daniel Normolle wrote:
> ...re: 6AS7G...
> I have heard figures like this bandied about, and have some
experience with
> this tube, and, while they are subject to some imbalance, I
have not seen
> this kind of variation. Paul, is this actually your
experience, or is this
> one of those Urban Tube Myths, like the Tijuana 300B?
Here's the data I took on the 5 6AS7/6080 types I had in my
stash (the
Svetlana was borrowed from Doc. B. who got it from Eric
Barbour; I
don't know if it was selected for balance or not but it might
have
been). The total current (both sections) is shown for identical
fixed
bias on both sections. The RCA #2 was unstable, drifting
over the 2-3
minute test period - it's probably a dud.
Tube current-x2 unbalance-mA
Svetlana 150 12.6
JAN by RCA - #1 138 2
JAN by RCA - #2 190* 71
plain RCA 75 40
H-P by GE >200 40
Of course, cathode resistor bias would help - but they're still
pretty
variable. There's a spec for variation - I can't put my hands on
it
right now - but it's amazingly broad. I think all but the dud are
within the spec.
> ... Nonetheless, I
> don't think the 6AS7 is sufficiently linear to use as a driver
without some
> sort of feedback (e.g., as a cathode follower, where it
excels).
I agree - guess I was unclear - the idea was a single 6AS7
as P-P
output, with a P-P drive (either tapped choke or transformer
coupled)
and transformer phase-splitter input. Throw in a few chokes
and
separate filament and bias transformers, and you get eight
pieces of
iron and two tubes per monoblock - well, it sounded cool at
the time!
The circuit is still under dissultory development, if I ever get it
to
work OK I'll offer it to Doc for VALVE, mostly as a lesson in
how much
difference there is between the first cool idea and something
you
actually like to listen to. (btw, Dave Dintenfass is working on
a
similar unit, with similar experiences.) It certainly reminds
me why I
like simple SE circuits!
- -Paul Joppa
=========================================================================
From: "Danielak, Robert M" <robert.m.danielak@lmco.com>
Subject: 6as7 line stage RE: 71A and preamp tubes
Date: Mon, 19 Oct 1998 12:35:59 -0400
Source: Sound Digest Archive v01.n459
> > Anyone tried the 6AS7 in a parafeed or regular SE design?
>
> not me.
>
> -grego
>
me niether, at least not IT coupled.
i did a crazy resistor loaded line stage using a single 6as7/6080.
the thought was to make a hi-current amp with practically unity gain.
i ran them at something like 130V / 80mA.
1.5K or 2K resistive load. 2uF out.
got like 1.2X gain...
didn't sound like anything. no difference with or without.
i was hoping to warm up my CD output a little (given the high D2
of the 6as7).
nada.
i still have it laying around. figured if i ever had to drive a few miles
of cable, it'd be good to have available.
neat little 4" x 6" x 3" package, too.
bob.d.
=========================================================================
From: Scott Grammer <tubedude@cdc.net>
Subject: Re: 6as7 line stage RE: 71A and preamp tubes
Date: Mon, 19 Oct 1998 18:56:21 -0400
Source: Sound Digest Archive v01.n460
Danielak, Robert M wrote:
> > > Anyone tried the 6AS7 in a parafeed or regular SE design?
> >
> > not me.
> >
> > -grego
> >
> (snip)
YES!
My favorite amp, the one I use every day in the living room is based around a
single 6AS7G. It includes a 6SL7GT and a 5AR4. It uses no NFB, not even local
degeneration, and the output trannies are PP 8kohm jobbies from an Eico ST35
amp. I run the halves of the 6AS7G at 33mA and 400V, although 100V of that is
burned up in the cathode resistors (3k@25W). The measured power out is 2.5wpc
at clipping above 100Hz, frequency response at 1 watt is 17-65,000Hz +0,
- -3dB. Distortion at 2 watts out is about 1% at 1kHz, at 1 watt it is around
0.5%. I run 8 ohm speakers on the 16 ohm taps, resulting in a 4k laod for the
tube. This trick also provides more primary inductance than a similar true 4k
tranny would give. That's important when you're cheating and running a PP
tranny SE like me! :-)
One hint, though. Don't use a 6AS7G with silicon rectifiers, or with a
directly heated tube rectifier. You MUST have 10 or so seconds of warmup for
the 6AS7G cathode before applying the plate voltage, or the tube will die a
quick (~5 seconds) death. A 5AR4 works perfectly in supplying the necessary
delay.
Cheers!
S.G.
- --
Visit TubeDude's Webpage of Vacuum Tube Lore! http://www.cdc.net/~tubedude
Also check out Smoke Free Youth!
http://www.cdc.net/~tubedude/smokefreeyouth.html
See what I have for sale! http://members.ebay.com/aboutme/tubedude@cdc.net/
=========================================================================
From: Douglas Purl <dcp@selway.umt.edu>
Subject: Re: 6as7 line stage RE: 71A and preamp tubes
Date: Tue, 20 Oct 1998 02:21:53 -0600 (MDT)
Source: Sound Digest Archive v01.n461
On Mon, 19 Oct 1998, Scott Grammer wrote:
> My favorite amp, the one I use every day in the living room is based around a
> single 6AS7G. It includes a 6SL7GT and a 5AR4. It uses no NFB, not even local
> degeneration, and the output trannies are PP 8kohm jobbies from an Eico ST35
> amp. I run the halves of the 6AS7G at 33mA and 400V, although 100V of that is
> burned up in the cathode resistors (3k@25W). The measured power out is 2.5wpc
> at clipping above 100Hz, frequency response at 1 watt is 17-65,000Hz +0,
> -3dB. Distortion at 2 watts out is about 1% at 1kHz, at 1 watt it is around
> 0.5%. I run 8 ohm speakers on the 16 ohm taps, resulting in a 4k laod for the
> tube. This trick also provides more primary inductance than a similar true 4k
> tranny would give. That's important when you're cheating and running a PP
> tranny SE like me! :-)
Have you measured the output impedance on this device?
Doug Purl
=========================================================================
From: Grover Gardner <groverg@postoffice.att.net>
Subject: Re: 6as7 line stage RE: 71A and preamp tubes
Date: Wed, 21 Oct 1998 05:32:30 -0500
Source: Sound Digest Archive v01.n462
At 6:56 PM -0400 10/19/98, Scott Grammer wrote:
>Danielak, Robert M wrote:
>
>> > > Anyone tried the 6AS7 in a parafeed or regular SE design?
I've played around with the various regulator triodes--7236, 5998, 6080,
6336--interestingly, they vary in tone like the 45, 46. 71A etc.
But the differences are subtle and, except for slight variances, they all
have a remarkably neutral signature. Bob's experience with a 6AS7 line
stage sounding like "nothing" doesn't surprise me. Not the romance one
might be seeking from DHTs, but OTOH remarkable BW and capable of real
sweetness if they're set up properly.
I hear a very different different harmonic texture which takes some
adjustment compared to a DHT, but if you give them time and keep a good
"attitude" :-) these tubes can offer some pretty cool sounds.
Grover Gardner
groverg@postoffice.att.net
=========================================================================
From: evaguido <EvaGuido@iaehv.nl>
Subject: Re: 6as7 line stage RE: 71A and preamp tubes
Date: Thu, 22 Oct 1998 11:37:45 +0200
Source: Sound Digest Archive v01.n463
I once build a 6AS7 linestage (common cathode) and it sounded harsh,
metallic. That sound had consistence with OTL amps equiped with 6AS7.
I never touched the 6AS7 after that
Guido
At 12:35 19-10-98 -0400, Danielak, Robert M wrote:
>
>> > Anyone tried the 6AS7 in a parafeed or regular SE design?
>>
>> not me.
>>
>> -grego
>>
>me niether, at least not IT coupled.
>
>i did a crazy resistor loaded line stage using a single 6as7/6080.
>
>the thought was to make a hi-current amp with practically unity gain.
>
>i ran them at something like 130V / 80mA.
>1.5K or 2K resistive load. 2uF out.
>
>got like 1.2X gain...
>
>didn't sound like anything. no difference with or without.
>i was hoping to warm up my CD output a little (given the high D2
>of the 6as7).
>
>nada.
>
>i still have it laying around. figured if i ever had to drive a few miles
>of cable, it'd be good to have available.
>
>neat little 4" x 6" x 3" package, too.
>
>bob.d.
>
>
=========================================================================
From: trs@carlsmith.com
Subject: 6as7 line stage RE: 71A and preamp tubes -Reply
Date: Tue, 20 Oct 1998 9:31:34 -1000
Source: Sound Digest Archive v01.n462
An interesting SE 6AS7 design by Cy Brenneman was
published as "Maximum Sound Quality From A Single 6AS7"
on the Svetlana website at:
http://www.svetlana.com/docs/TechBulletins/appnoteNO.26.html
The design includes a means for balancing the two triode
elements in the 6AS7.
Regards, Tom Sylvester trs@carlsmith.com
>>> "robert.m.danielak@lmco.com" 10/19/98 07:40am >>>
> > Anyone tried the 6AS7 in a parafeed or regular SE
design?
>
> not me.
>
> -grego
>
me niether, at least not IT coupled.
i did a crazy resistor loaded line stage using a single
6as7/6080.
the thought was to make a hi-current amp with practically
unity gain.
i ran them at something like 130V / 80mA.
1.5K or 2K resistive load. 2uF out.
got like 1.2X gain...
didn't sound like anything. no difference with or without.
i was hoping to warm up my CD output a little (given the high
D2
of the 6as7).
nada.
i still have it laying around. figured if i ever had to drive a few
miles
of cable, it'd be good to have available.
neat little 4" x 6" x 3" package, too.
bob.d.
=========================================================================
From: Paul Joppa <pdj@ISDNseattle.net>
Subject: Re: 6AS7's....
Date: Sun, 06 Dec 1998 21:15:23 -0800
Source: Sound Digest Archive v01.n523
Wow! I'm impressed - thanks for the *pile* of data! This looks much
better than my initial (and discouraging) attempt. Of course, all mine
(except the dud second RCA) were different brands; looks like the
brand variation is larger than the sample variation within brands. And
the pair differences are smaller than I found - guess my sample was
just too small to give statistically meaningful results. Very
encouraging. I'm encouraged enough to get back to my P-P amp.
Thanks again,
- -Paul Joppa
Torbjxrn Lien wrote:
> ...big snip...
> Here's afew examples in condenced form :
>
> RCA 6080: 75V anode, -15V grid. mA/V always betv.7 and 8
> 14 tested. Average current spread between internal triodes was: 9%
> (3,12,21,5,13,9,16,5,3,6,12,4,11,8)% difference.
> Average current: 97 mA
> Lowest reading 76mA, highest 117mA,
> None tested really atypical, but 1 or 2 could be left out for
> improvement of the figures.
>
> RCA 6AS7, late 50's..75V/-19V. mA/V always betveen 6,5 and 7,2.
> 8 tested.2 tested atypical and were left out.
> Average current spread between internal triodes was:6,3%
> (2,0,8,9,10,9,)% difference.
> Average current: 84mA
> Lowest reading 74mA, highest 95mA
>
> I could go on and on, but I bet it would be boring for most of you.
> IMHO US-made nos 6AS7's are generally sound and good tubes. If making
> an OTL-amp, simply buy all output-tubes at once, from the same lot.-
> Be prepared to set aside 2 atypical, out of 10 tubes. If you double
> up and buy your second set (for spares) at the same time, it is quite
> possible to get the current-draw of the 4 output-tube sets
> reasonably matched.
=========================================================================
From: "=?ISO-8859-1?Q?Torbj=F8rn_Lien?=" <mdrivekl@online.no>
Subject: Re: 6AS7's....
Date: Sun, 6 Dec 1998 21:24:42 +0100
Source: Sound Digest Archive v01.n523
Paul Joppa:
(Showed measurements on (5)dubious 6AS7's..)
myself wrote:
> OOOHHhh,-this wasn't much good..Are you sure that you havent been
> collecting duds? [snip!]
.......................Through the years I've been collecting the
> el-cheapo 6AS7/6080 ..........
> Caused by the alarming figures [snipped] I'll test some samples
> during the weekend and report back.
>
Done,-!
These rumours of the 6AS7/6080 being vildly varying in emission and
transconductance doesn't hold water. Atleast not to me, after testing
around 100 nos samples this weekend. They behave, in spread, IMHO like
any other non-selected tube-type.
Procedure: I used my AVO VCM163 ,used 75V on the anode, and tested with
around 80-120mA current.Fixed value of neg. grid-voltage on the various
groups of tubes.
Transconductance: After a while I stopped taking notes. It varied
mainly with current, in very a predictible manner.Always between
(6 and 7)mA/V at lower currents, around 7-8 at higher currents.
Very consistent readings-
So, I consentrated on current imbalance between the two triodes.
And on average current variation in the groups of tubes,-
BTW The most significant differences in bias was betw. groups.
Shows the importanse of sticking to one brand/vintage when
loading your OTL..
Here's afew examples in condenced form :
RCA 6080: 75V anode, -15V grid. mA/V always betv.7 and 8
14 tested. Average current spread between internal triodes was: 9%
(3,12,21,5,13,9,16,5,3,6,12,4,11,8)% difference.
Average current: 97 mA
Lowest reading 76mA, highest 117mA,
None tested really atypical, but 1 or 2 could be left out for
improvement of the figures.
RCA 6AS7, late 50's..75V/-19V. mA/V always betveen 6,5 and 7,2.
8 tested.2 tested atypical and were left out.
Average current spread between internal triodes was:6,3%
(2,0,8,9,10,9,)% difference.
Average current: 84mA
Lowest reading 74mA, highest 95mA
I could go on and on, but I bet it would be boring for most of you.
IMHO US-made nos 6AS7's are generally sound and good tubes. If making
an OTL-amp, simply buy all output-tubes at once, from the same lot.-
Be prepared to set aside 2 atypical, out of 10 tubes. If you double
up and buy your second set (for spares) at the same time, it is quite
possible to get the current-draw of the 4 output-tube sets
reasonably matched.
Regards,
Torbjoern Lien
>
>
>
>
=========================================================================
From: "=?ISO-8859-1?Q?Torbj=F8rn_Lien?=" <mdrivekl@online.no>
Subject: 6AS7's....- and tiny OTL consept
Date: Sat, 5 Dec 1998 02:00:16 +0100
Source: Sound Digest Archive v01.n520
> Paul Joppa wrote:
>
> > Here's the data I took on the 5 6AS7/6080 types I had in my stash
.....[Horrible measurements snipped!!]
OOOHHhh,-this wasn't much good..Are you sure that you havent been
collecting duds?(I've been on and off this OTL-project for around
ten years,-(hmmm,-lets see,-10 years,-and I'm about,-realistically,-
75% finished,-...Uhuh..that makes speed of progress to be about
3,33 years for the remaining 25%...add to that other more exiting
things in life and two children, work.....(I'm now shifting to the
"thinking of early projects" depressed mode........) Uhmm,-yes,-.....
If lucky,thei're done by winther 2002 or something.)
But I digress,-Through the years I've been collecting the
el-cheapo 6AS7/6080 for the output.I guess I posess well over 100
pieces by now.(Must have some spares when the amp is completed, no?)
- -Of various brands, but in series of atleast 12-15ea.....
Caused by the alarming figures [snipped] I'll test some samples
during the weekend and report back.
The tiny OTL: This can ofcourse be done,-But, even though we use
only one output tube to get 5W out or something, it won't be an
elegant and sneaky circuit. Look at early work from Futterman,-this
I think is eh, atleast a nice try,-but he uses, was it 10 of the 12B4
in paralell..
Take another look at "normal" OTL's. There's a reason for the
paralelling of tubes,and high wattage,-: low output Z without
too much feedback.
A unit with 8 such tubes can deliver around 60W with decent output¨R,
feedback included, so with one tube, lets say 5-7,5 W...
Now,-to do this, and get just a remote useable output-resistance, we
need to apply "some" negative feedback..And fully understand that the
output tube will be badly abused, probably killed,-if actually forced
to deliver this power continously...But on the other hand...feeding
music power to a Lowter-unit is something *completely* different,-
The tube might actually survive for a long time...and even if it
blows every now and then,-it's cheap, and could easily be replaced..
Hmm,-if it blows every now and then, a bullet-proof circuit is
needed,- so that it doesn't fry the voicecoil..And pref. without
fuses...
This *sets* the topology: A workable approach is to use the
Electrovoice circlotron circuit: Each output triode has a dedicated
floating PSU, and in paralell with the load: a centre tapped choke.
(With reasonable inductance, and only afew ohms DC...Cause this is our
speaker saver!)This coil is a paralell, invinsible device,-so it's
still a OTL-amp....
The only possible mode of this stage is class A2: As much standing
current as the tube can take (that is 125mA/section) and a meaty
driver that can deliver *lots* of A2 voltage...This sets the 2 output
rails to be 80V, for a 10W+10w anode dissipation..
The output resistance without feedback is around 300 ohms in class A
and probably around 500 ohms in A2..To get the output resistance
down to, say 4 ohm, we must apply around 40dB of neg. voltage
feedback...This can be done, and one possible setup can now be
suggested:
Output-stage: One 6AS7, working on 80V, 125mA/section, choke-coupled
circlotron..
Driver: Cathode or pref. White-followers, with ex. the 6BL7, and
40-50mA standing current,-NB! direct coupled to output grids.
Frontend Internal voltage amp: Balanced diff-stage with a high gain
dual cascode of some sort,-or maybe a 12AX7 diff-stage......
These 3 stages is the power output stage only. With 100% negative
feedback applied from output to input in a balanced fashion,
the output R is useable....
The power output stage must be driven by a dedicated input-to
balanced output voltage stage with good balance, but only moderate
gain is needed....
Ohwell,-guess there is a reason that amps like these are few and
far in between,- But if anyone want to make an amp with a decent
obscurity-factor, here it is!
:)T.L.
>
>
>
>
>
=========================================================================
From: Rick Francis <rfranci@uoft03.UTOLEDO.EDU>
Subject: 6AS7s galore for you OTL guys
Date: Sat, 21 Mar 1998 18:12:10 -0500 (EST)
Source: Sound Digest Archive v01.n225
Also for use as cathode followers! With this discussion of OTLs etc. I
thought I'd mention that I have a batch of NIB GE 6AS7s, and lots of used
ones. Also a pair of 6336s I'll probably never use. Also 20 amp 6.3 vct
Stancor trannies to light them up -- 5 amps each for 6336s!
I bought a batch of tubes and got more of these than I'll ever need, so
I'm happy to swap or sell to make space. Also lots of smaller NIB tubes
I'll eventually peddle. Also pair of RCA 6L6 black-plates, NIB, and a
third that looks new but box marked used.
Contact me privately if any of this interests you.
Rick Francis, rfranci@uoft03.utoledo.edu
=========================================================================
From: Thomas Woodley <twoodley@freespace.net>
Subject: 6B4Gs/6A3s for sale
Date: Tue, 11 Aug 1998 07:18:34 -0400 (EDT)
Source: Sound Digest Archive v01.n384
Hi all - I dug out some 6B4Gs and 6A3s I'd like to sell in two packages
(rather not break them up). Specifics follow, including tested relative
Gm (%) and, for used ones, the expected life. All are bi-plate types and
those with flat plates (FP) are indicated (they look like 45 plates but
about 50% longer which, to me, suggests that, if a 45 can dissipate 9
watts, they should be good for at least 20).
6B4G-types - Asking $120US for lot (4 NOS and 3 used):
- Pair 6B4G Philco USA, NIB, Gm 101% for both
- 1 6B4G GE Canada, NIB, FP-type, Gm 101%
- Pair 6B4G Tung-Sol USA, used, Gm 91 and 94%, life-exp. like new
(octal centre "pin" (?) broken on one, but fine otherwise, both
made for Marconi Canada)
- 6A5G Sylvania USA, NIB (Box Standard Brand), FP-type, Gm 105%
- 6A5G Philco USA, used, Gm 80%, life-exp. not great.
6A3s - Asking $100US for lot (4NOS and 2 used):
- Pair GE Canada, NIB, Gm 102% for both
- 1 Philco USA, NIB, Gm 102%
- 1 Tung-Sol USA, NIB (Box GE Canada, which it was likely made
for), FP-type, Gm 97%
- Pair made for GE Canada, used (one loose base with small piece
of glass inside, but tests fine), Gm 93 and 94%, life-exp. long
If interested please e-mail me directly (twoodley@freespace.net).
Best, Thom W.
=========================================================================
From: "Robert Clark" <rclark@insightinc.com>
Subject: 6B5/6n6-G SE Amp
Date: Sun, 17 May 1998 09:43:12 -0400
Source: Sound Digest Archive v01.n281
Is anyone aware of a single ended amp circuit that uses the 6B5? Its a dual
section triode: first section is an input tube direct coupled to the second
section output tube which is good for a max. of 4 watts. This sounds to good
to be true. I have to assume there is a catch somewhere or I would have read
about the tube by now and they wouldnt cost only $15 a piece. ?????
=========================================================================
From: Grover Gardner <groverg@postoffice.att.net>
Subject: Re: 6B5/6n6-G SE Amp
Date: Mon, 18 May 1998 12:44:27 -0500
Source: Sound Digest Archive v01.n282
At 9:43 AM -0400 5/17/98, Robert Clark wrote:
>Is anyone aware of a single ended amp circuit that uses the 6B5? Its a dual
>section triode: first section is an input tube direct coupled to the second
>section output tube which is good for a max. of 4 watts. This sounds to good
>to be true. I have to assume there is a catch somewhere or I would have read
>about the tube by now and they wouldnt cost only $15 a piece. ?????
Looking at the specs there are several catches, first being the zero grid
bias of the input half, leading me to question its linearity, the second
being the very high plate resistance (24K), the specs calling for a 7K
load. Seems like it would *not* be the bee's knees, sonically, but who
knows? Sounds like a workhorse tube as opposed to a hidden beauty.
Grover
=========================================================================
From: "Edward W. Johnson" <rb1304@alltel.net>
Subject: 6BL4
Date: Fri, 20 Feb 1998 16:16:54 -0500
Source: Sound Digest Archive v01.n197
Anyone had experiance using these in cicuits,look like they could be
usefull in HV applications?
=========================================================================
From: Thomas Danley <Tom@ppci.com>
Subject: 6BL7 curves
Date: Sat, 04 Apr 1998 21:59:54 -0600
Source: Sound Digest Archive v01.n245
Hi all
Does anyone know where I can get curves for a 6BL7 dual triode?
Has anyone looked at the curves for a 6080 (6AS7) as a class"A" cathode
follower? It looks like it would be very linear in that application.
Best Regards,
Thomas Danley
ITC
=========================================================================
From: evaguido <EvaGuido@iaehv.nl>
Subject: Re: 6BL7 curves
Date: Sun, 05 Apr 1998 23:21:25 +0200
Source: Sound Digest Archive v01.n245
At 21:59 4-4-98 -0600, Thomas Danley wrote:
>Hi all
>
>Does anyone know where I can get curves for a 6BL7 dual triode?
>
>Has anyone looked at the curves for a 6080 (6AS7) as a class"A" cathode
>follower? It looks like it would be very linear in that application.
Might be. Look for independancy of transconductance as function of current
Guido
>Best Regards,
>
>Thomas Danley
>ITC
>
>
=========================================================================
From: Bob Danielak <rdaniela@ew.lmms.lmco.com>
Subject: Re: 6BL7 curves
Date: Mon, 01 Jan 1996 02:01:50 -0500
Source: Sound Digest Archive v01.n246
Thomas Danley wrote:
>
> Hi all
>
> Does anyone know where I can get curves for a 6BL7 dual triode?
>
> Has anyone looked at the curves for a 6080 (6AS7) as a class"A" cathode
> follower? It looks like it would be very linear in that application.
> Best Regards,
>
> Thomas Danley
> ITC
hi tom,
i have both on my computer at work.
i'm working from home on a laptop, today.
i'll try to remember to send them tomorrow, but an e-mail
nudge wouldn't hurt (use robert.m.danielak@lmco.com).
i did the 6080/6as7 CF curves by hand a while back.
but i can also re-do them using pspice.
would have to scan the old ones.
btw: you are correct. the 6as7 is pretty linear in CF.
i used them in a circlotron-type amp (using an OPT).
i also use them as A2 drivers for sv811-10, etc...
if anyone else is interested, i can put this stuff on my web-site.
bob.d.
=========================================================================
From: "Chris Beck" <cbeck@brewercompany.com>
Subject: Re: 6BM8 P-to-P Load Res., Sansui SM-21 receiver
Date: Mon, 5 Oct 1998 07:08:28 -0500
Source: Sound Digest Archive v01.n441
I believe you can use 8K plate to plate. Same basic iron as most PP EL84
amps. A little PP 6BM8 amp has been on my project list for quite a while
now. Something always comes up... There is a nice schematic on the
Svetlana web pages based upon the Sansui design. Mullard also published a
neat design with a little different front end treatment. I use this tube
as a driver to my SE SV572-10 amps. Works nice.
I don't know about your Sansui, but I have heard that they had darn good
iron.
Chris Beck
See my web page at: http://www.execpc.com/~n9zes/index.htm
- ----------
> From: Richard A. Francis <rfranci@uoft03.utoledo.edu>
> To: Sound Practices List <sound@deliverator.io.com>
> Subject: 6BM8 P-to-P Load Res., Sansui SM-21 receiver
> Date: Monday, October 05, 1998 6:10 AM
>
>
> Would someone be so kind as to tell me the plate-to-plate load resistance
> for PP 6BM8s? I haven't got it in my books.
>
> I'd like to know more about the OPTs in a Sansui SM-21 (PP 6BM8). They
are
> potted and look pretty serious.
>
> Thanks,
> Rick Francis, rfranci@uoft03.utoledo.edu
>
> Had enough Monica madness? Go to http://www.moveon.org to sign the
> petition.
>
>
=========================================================================
From: "Richard A. Francis" <rfranci@uoft03.utoledo.edu>
Subject: 6BM8 P-to-P Load Res., Sansui SM-21 receiver
Date: Mon, 05 Oct 1998 07:10:30 -0400 (EDT)
Source: Sound Digest Archive v01.n441
Would someone be so kind as to tell me the plate-to-plate load resistance
for PP 6BM8s? I haven't got it in my books.
I'd like to know more about the OPTs in a Sansui SM-21 (PP 6BM8). They are
potted and look pretty serious.
Thanks,
Rick Francis, rfranci@uoft03.utoledo.edu
Had enough Monica madness? Go to http://www.moveon.org to sign the
petition.
=========================================================================
From: Andrej Deticek <andrej.deticek@siol.net>
Subject: Re: 6BM8 P-to-P Load Res., Sansui SM-21 receiver
Date: Mon, 05 Oct 1998 14:45:53 +0100
Source: Sound Digest Archive v01.n441
Richard A. Francis wrote:
>
> Would someone be so kind as to tell me the plate-to-plate load resistance
> for PP 6BM8s? I haven't got it in my books.
>
> I'd like to know more about the OPTs in a Sansui SM-21 (PP 6BM8). They are
> potted and look pretty serious.
>
> Thanks,
> Rick Francis, rfranci@uoft03.utoledo.edu
Hello,
I can answer only the first part of the question.
Appropriate value of plate-to-plate load resistance of PP connected
tubes depends on two things: Plate voltage and whether tubes are cathode
or fix biased. At higher plate voltage one should use a little higher
plate load. Fix biased PP tubes are also usually used with a higher
plate load.
Data from different data books for 6BM8:
1)GE: At Up = 200 V, R p/p = 5k6
2)RTT (German): At Up = 200 V, R p/p = 5k6
3)PHILLIPS: Class AB, common cathode bias: At 200V - Rpp=4k5, At 250V -
Rpp=10k
4)Electronic Universal Vade-Mecum: Cathode Bias: At 200V - Rpp=5k, At
250V - Rpp=10k
Hope this helps,
Andrej Deticek
=========================================================================
From: "Chris Beck" <cbeck@brewercompany.com>
Subject: Re: 6BM8 Was(Re: Paraspud EL84 expperiment)
Date: Wed, 30 Dec 1998 07:07:23 -0600
Source: Sound Digest Archive v01.n552
Just a comment,
In my amps, I don't get full output of the SV572. However, this is due to
circuit topology and voltages used rather than a driver TUBE limitation.
If I wanted to, I could run a direct coupled cathode follower with ALOT
more voltage on the 6BM8 and SV572, and get 30-40 watts. But, the circuit
I used is stump simple, sounds great, and is reliable.
Enjoy!
Chris Beck
See my web page at: http://www.execpc.com/~n9zes/index.htm
- ----------
> From: Johari Yip <hfyip@pacific.net.sg>
> To: Chris Beck <n9zes@execpc.com>; Jon Lane <jhlane@email.msn.com>
> Cc: JoeList <sound@io.com>; Richard A. Francis
<rfranci@uoft03.utoledo.edu>
> Subject: 6BM8 Was(Re: Paraspud EL84 expperiment)
> Date: Wednesday, December 30, 1998 12:28 AM
>
> Hi everyone,
>
> On the subject of the 6BM8, a tube that's beefy enough to drive the SV572
> series of tube to max. output must be fantastic. I'm curious to know if
> there's a separate triode and pentode that's equivalent electrically to
> that of the 6BM8? Thanks for any suggestions.
>
> Regards,
> Johari
>
> ----------
> > From: Chris Beck <n9zes@execpc.com>
> > To: Jon Lane <jhlane@email.msn.com>
> > Cc: JoeList <sound@io.com>; Richard A. Francis
> <rfranci@uoft03.utoledo.edu>
> > Subject: Re: Paraspud EL84 expperiment
> > Date: Wednesday, December 30, 1998 11:37 AM
> >
> > Regarding the 6BM8, I use these as drivers in my SE amps, and to me,
> > they sound fantastic. I've little to compare them to, but I think they
> > work great. Besides, they are cheap and available.
> >
> > Chris Beck
> >
> > see my web page at: http://www.execpc.com/~n9zes
> >
> > Jon Lane wrote:
> >
> > > > On Tue, 29 Dec 1998, Henry Platt wrote:
> > > >
> > > > > Tonight I finally tried an idea I have been
> > > > musing for a couple weeks, an
> > > > > EL84 Parafeed one tuber. I have enjoyed the
> > > > sound of my EL84 PP with IT
> > > > (SNIP)
> > > > > is very good, this one tube amp idea. I have
> > > > always loved the EL84, and this
> > > > > is what it really sounds like, smooth and
> > > > detailed. What are some other good
> > > > > tubes for this type of amp?
> > > > >
> > > > Henry, have you thought about 6973 tubes? Also,
> > > > I wonder about the many
> > > > octals that seems sorta like a 6BQ5: 6V6, 6W6,
> > > > 6Y6, 6K6... [Blatant
> > > > commercialism: I have many of all those octals to
> > > > sell, used]
> > > >
> > > > Rick
> > >
> > > Or perhaps those nicely made triode/power pentodes, the
> > > mighty ECL82/6BM8. And I, coincidentally, have buckets of
> > > those...NOS, even.
> > >
> > > Jon Lane
=========================================================================
From: "Johari Yip" <hfyip@pacific.net.sg>
Subject: 6BM8 Was(Re: Paraspud EL84 expperiment)
Date: Wed, 30 Dec 1998 14:28:31 +0800
Source: Sound Digest Archive v01.n552
Hi everyone,
On the subject of the 6BM8, a tube that's beefy enough to drive the SV572
series of tube to max. output must be fantastic. I'm curious to know if
there's a separate triode and pentode that's equivalent electrically to
that of the 6BM8? Thanks for any suggestions.
Regards,
Johari
- ----------
> From: Chris Beck <n9zes@execpc.com>
> To: Jon Lane <jhlane@email.msn.com>
> Cc: JoeList <sound@io.com>; Richard A. Francis
<rfranci@uoft03.utoledo.edu>
> Subject: Re: Paraspud EL84 expperiment
> Date: Wednesday, December 30, 1998 11:37 AM
>
> Regarding the 6BM8, I use these as drivers in my SE amps, and to me,
> they sound fantastic. I've little to compare them to, but I think they
> work great. Besides, they are cheap and available.
>
> Chris Beck
>
> see my web page at: http://www.execpc.com/~n9zes
>
> Jon Lane wrote:
>
> > > On Tue, 29 Dec 1998, Henry Platt wrote:
> > >
> > > > Tonight I finally tried an idea I have been
> > > musing for a couple weeks, an
> > > > EL84 Parafeed one tuber. I have enjoyed the
> > > sound of my EL84 PP with IT
> > > (SNIP)
> > > > is very good, this one tube amp idea. I have
> > > always loved the EL84, and this
> > > > is what it really sounds like, smooth and
> > > detailed. What are some other good
> > > > tubes for this type of amp?
> > > >
> > > Henry, have you thought about 6973 tubes? Also,
> > > I wonder about the many
> > > octals that seems sorta like a 6BQ5: 6V6, 6W6,
> > > 6Y6, 6K6... [Blatant
> > > commercialism: I have many of all those octals to
> > > sell, used]
> > >
> > > Rick
> >
> > Or perhaps those nicely made triode/power pentodes, the
> > mighty ECL82/6BM8. And I, coincidentally, have buckets of
> > those...NOS, even.
> >
> > Jon Lane
=========================================================================
From: Chris Beck <n9zes@execpc.com>
Subject: Re: 6BM8 Was(Re: Paraspud EL84 expperiment)
Date: Wed, 30 Dec 1998 19:46:09 -0600
Source: Sound Digest Archive v01.n553
Johari, take a look at my webpage for schematics: http://www.execpc.com/~n9zes
To answer your question about the plate current, your best bet is to go to the
Svetlana web page at: http://www.svetlana.com. There you can download data
sheets in Adobe Acrobat format (you can download the reader for free), and see
where the currents/voltages fall for different bias points. If memory serves
me, at zero bias and 900V, the 572-10 will be way past maximum dissipation of
125W. I run around 100-120 mA at 480 volts on the plate. Problem with running
more current is there aren't many output trannies that will handle that much
current. Even my Electra-Prints are only rated up to 150mA or so. To run
900V, you'll need some negative bias. Look at the data sheets and you'll see.
Chris
Johari Yip wrote:
> Hi Chris,
>
> Care to elaborate on the circuitry of your amp? Just a question regarding
> the current of the SV572-10. How much plate current will the SV572-10 be
> drawing at 900V plate voltage at even bias at the grid?
>
> Cheers,
> Johari
>
> ----------
> > From: Chris Beck <cbeck@brewercompany.com>
> > To: Johari Yip <hfyip@pacific.net.sg>; Chris Beck <n9zes@execpc.com>; Jon
> Lane <jhlane@email.msn.com>
> > Cc: JoeList <sound@io.com>; Richard A. Francis
> <rfranci@uoft03.utoledo.edu>
> > Subject: Re: 6BM8 Was(Re: Paraspud EL84 expperiment)
> > Date: Wednesday, December 30, 1998 9:07 PM
> >
> > Just a comment,
> >
> > In my amps, I don't get full output of the SV572. However, this is due
> to
> > circuit topology and voltages used rather than a driver TUBE limitation.
> > If I wanted to, I could run a direct coupled cathode follower with ALOT
> > more voltage on the 6BM8 and SV572, and get 30-40 watts. But, the
> circuit
> > I used is stump simple, sounds great, and is reliable.
> >
> > Enjoy!
> >
> > Chris Beck
> >
> > See my web page at: http://www.execpc.com/~n9zes/index.htm
> >
> > ----------
> > > From: Johari Yip <hfyip@pacific.net.sg>
> > > To: Chris Beck <n9zes@execpc.com>; Jon Lane <jhlane@email.msn.com>
> > > Cc: JoeList <sound@io.com>; Richard A. Francis
> > <rfranci@uoft03.utoledo.edu>
> > > Subject: 6BM8 Was(Re: Paraspud EL84 expperiment)
> > > Date: Wednesday, December 30, 1998 12:28 AM
> > >
> > > Hi everyone,
> > >
> > > On the subject of the 6BM8, a tube that's beefy enough to drive the
> SV572
> > > series of tube to max. output must be fantastic. I'm curious to know if
> > > there's a separate triode and pentode that's equivalent electrically to
> > > that of the 6BM8? Thanks for any suggestions.
> > >
> > > Regards,
> > > Johari
> > >
> > > ----------
> > > > From: Chris Beck <n9zes@execpc.com>
> > > > To: Jon Lane <jhlane@email.msn.com>
> > > > Cc: JoeList <sound@io.com>; Richard A. Francis
> > > <rfranci@uoft03.utoledo.edu>
> > > > Subject: Re: Paraspud EL84 expperiment
> > > > Date: Wednesday, December 30, 1998 11:37 AM
> > > >
> > > > Regarding the 6BM8, I use these as drivers in my SE amps, and to me,
> > > > they sound fantastic. I've little to compare them to, but I think
> they
> > > > work great. Besides, they are cheap and available.
> > > >
> > > > Chris Beck
> > > >
> > > > see my web page at: http://www.execpc.com/~n9zes
> > > >
> > > > Jon Lane wrote:
> > > >
> > > > > > On Tue, 29 Dec 1998, Henry Platt wrote:
> > > > > >
> > > > > > > Tonight I finally tried an idea I have been
> > > > > > musing for a couple weeks, an
> > > > > > > EL84 Parafeed one tuber. I have enjoyed the
> > > > > > sound of my EL84 PP with IT
> > > > > > (SNIP)
> > > > > > > is very good, this one tube amp idea. I have
> > > > > > always loved the EL84, and this
> > > > > > > is what it really sounds like, smooth and
> > > > > > detailed. What are some other good
> > > > > > > tubes for this type of amp?
> > > > > > >
> > > > > > Henry, have you thought about 6973 tubes? Also,
> > > > > > I wonder about the many
> > > > > > octals that seems sorta like a 6BQ5: 6V6, 6W6,
> > > > > > 6Y6, 6K6... [Blatant
> > > > > > commercialism: I have many of all those octals to
> > > > > > sell, used]
> > > > > >
> > > > > > Rick
> > > > >
> > > > > Or perhaps those nicely made triode/power pentodes, the
> > > > > mighty ECL82/6BM8. And I, coincidentally, have buckets of
> > > > > those...NOS, even.
> > > > >
> > > > > Jon Lane
=========================================================================
From: "Johari Yip" <hfyip@pacific.net.sg>
Subject: Re: 6BM8 Was(Re: Paraspud EL84 expperiment)
Date: Thu, 31 Dec 1998 09:35:49 +0800
Source: Sound Digest Archive v01.n553
Hi Chris,
Care to elaborate on the circuitry of your amp? Just a question regarding
the current of the SV572-10. How much plate current will the SV572-10 be
drawing at 900V plate voltage at even bias at the grid?
Cheers,
Johari
- ----------
> From: Chris Beck <cbeck@brewercompany.com>
> To: Johari Yip <hfyip@pacific.net.sg>; Chris Beck <n9zes@execpc.com>; Jon
Lane <jhlane@email.msn.com>
> Cc: JoeList <sound@io.com>; Richard A. Francis
<rfranci@uoft03.utoledo.edu>
> Subject: Re: 6BM8 Was(Re: Paraspud EL84 expperiment)
> Date: Wednesday, December 30, 1998 9:07 PM
>
> Just a comment,
>
> In my amps, I don't get full output of the SV572. However, this is due
to
> circuit topology and voltages used rather than a driver TUBE limitation.
> If I wanted to, I could run a direct coupled cathode follower with ALOT
> more voltage on the 6BM8 and SV572, and get 30-40 watts. But, the
circuit
> I used is stump simple, sounds great, and is reliable.
>
> Enjoy!
>
> Chris Beck
>
> See my web page at: http://www.execpc.com/~n9zes/index.htm
>
> ----------
> > From: Johari Yip <hfyip@pacific.net.sg>
> > To: Chris Beck <n9zes@execpc.com>; Jon Lane <jhlane@email.msn.com>
> > Cc: JoeList <sound@io.com>; Richard A. Francis
> <rfranci@uoft03.utoledo.edu>
> > Subject: 6BM8 Was(Re: Paraspud EL84 expperiment)
> > Date: Wednesday, December 30, 1998 12:28 AM
> >
> > Hi everyone,
> >
> > On the subject of the 6BM8, a tube that's beefy enough to drive the
SV572
> > series of tube to max. output must be fantastic. I'm curious to know if
> > there's a separate triode and pentode that's equivalent electrically to
> > that of the 6BM8? Thanks for any suggestions.
> >
> > Regards,
> > Johari
> >
> > ----------
> > > From: Chris Beck <n9zes@execpc.com>
> > > To: Jon Lane <jhlane@email.msn.com>
> > > Cc: JoeList <sound@io.com>; Richard A. Francis
> > <rfranci@uoft03.utoledo.edu>
> > > Subject: Re: Paraspud EL84 expperiment
> > > Date: Wednesday, December 30, 1998 11:37 AM
> > >
> > > Regarding the 6BM8, I use these as drivers in my SE amps, and to me,
> > > they sound fantastic. I've little to compare them to, but I think
they
> > > work great. Besides, they are cheap and available.
> > >
> > > Chris Beck
> > >
> > > see my web page at: http://www.execpc.com/~n9zes
> > >
> > > Jon Lane wrote:
> > >
> > > > > On Tue, 29 Dec 1998, Henry Platt wrote:
> > > > >
> > > > > > Tonight I finally tried an idea I have been
> > > > > musing for a couple weeks, an
> > > > > > EL84 Parafeed one tuber. I have enjoyed the
> > > > > sound of my EL84 PP with IT
> > > > > (SNIP)
> > > > > > is very good, this one tube amp idea. I have
> > > > > always loved the EL84, and this
> > > > > > is what it really sounds like, smooth and
> > > > > detailed. What are some other good
> > > > > > tubes for this type of amp?
> > > > > >
> > > > > Henry, have you thought about 6973 tubes? Also,
> > > > > I wonder about the many
> > > > > octals that seems sorta like a 6BQ5: 6V6, 6W6,
> > > > > 6Y6, 6K6... [Blatant
> > > > > commercialism: I have many of all those octals to
> > > > > sell, used]
> > > > >
> > > > > Rick
> > > >
> > > > Or perhaps those nicely made triode/power pentodes, the
> > > > mighty ECL82/6BM8. And I, coincidentally, have buckets of
> > > > those...NOS, even.
> > > >
> > > > Jon Lane
=========================================================================
From: Carter Hendricks <carterh@crl.com>
Subject: 6BQ5IT6BQ5PP
Date: Thu, 21 May 1998 21:26:17 -0500
Source: Sound Digest Archive v01.n288
Like many of usI've spent a lot of time staring at the
strange and wonderful schematics on the Sakuma/
Direct Heated web site.
www5.big.or.jp/~dh/index.html
The demise of a little amp I was using at the shop gave me
a chance to build a project based on a Sakuma design
[and his general construction practices]. The results
surprised me.
The donor amp was a muddy, thick sounding Stromberg
Carlson 6BQ5 PP.
The Sakuma design [from 1982] is all triode wired, 6BQ5
choke-loaded driver, IT, 6BQ5 PP.
Most everything was junkbox: Power supply from the
Stromberg Carlson, voltage doubler, a couple soft-recovery
diodes then 2 x 200uF Nichicon switcher 'lytics, 1.5Hy
200mA Hammond, some resistance to drop to 300v,
2 x 35uF oil caps for the drivers and outputs. 2 x 20uF
and 2 x 10uf Solens for the phono section, because I had
them and because of space requirements--I built this thing
on a 14x14 sheet of aluminum and quickly ran out of room.
Cool part: the PP's and driver 6BQ5s are straight from
Sakuma's design. I used the little nickel AES 10K:90K IT.
I put a small cap in the ground leg like a good parafeeder.
'Bought a couple of the IT's when others first talked about
them, then set them aside after someone said that they
measured awful. Maybe, but they seem to sound nice. I
loaded them with resistors plus small 100K stereo pots wired
as variable resistors. I've been playing with additional
loading and a small bit seems to strengthen bass and tone.
So far I am using Hammond 30H 40mA power supply chokes
as plate chokes. [I remember that Grover did something like
this and when he upgraded to better inductors the highs
improved. I have some slight glare across the overtones
on the upper third of the piano keyboard... Is that glare
the cheap choke, Grover?]. Can't wait to get some of
Mikey's real plate chokes!
{Note: I wrote this a couple weeks ago. The plate chokes
have since arrived. So has the freshly-painted Fulvia HF.
In cases like this, the shop wins. Upgrade/update, soon.}
The original Sakuma design used a step-up MC phono
transformer at the input, a 6C4, then Sakuma's very personal
RIAA, a volume control and another 6C4. I first built the amp
as a line level thing with just one 6C4 and that's how Tom
Ronan first heard it. I had more gain than I needed so later I
ran the pot right to the driver 6BQ5. Better. One could make a
tiny line amp with just the three tubes.
I was surprised at how pleasant the amp was. A bit less
detail than the SE 417 amp, and less separation between
instruments than it or the 2A3. That's pentodes for you?
But wonderful tone. Especially on Billie Holliday, horns,
drums, jazz guitar... Great range & dynamics. Weird.
It sounded so nice [and I had wondered if it would even
work!] that I went ahead with an integral, Sakuma-like phono
section. I wanted to stick with Sakuma principles, but
that presented certain difficulities. I didn't think the original
RIAA would have enough gain. I didn't think the original
RIAA would work with a more conventional system...
Sakuma's EQ is based on his complete system, and is,
well, unique. I asked John Leverault for help with the
Sakuma RIAA, & it isn't "accurate."
To solve the gain issue I went back to other Sakuma
designs and decided to use a 6SL7 in his style:
paralled sections, shared 250K plate resistor, shared
3 [3.3] K cathode resistor with 100uF bypass. Sakuma first
used a 30K series resistor [later a variable/adjustable
inductor] which isn't easy for a passive RIAA and a
junkbox of parts. I asked John for some advice about
using a larger R say about 70K & he asked what caps
I had and faxed back a passive RIAA tested on his
computer program.
[Sakuma often uses 5691's as a first tube, always with
250K plate R and 3K cathode resistor 100uF bypass.
But the fact that he is using paralled sections isn't even
hinted on the schematics and is buried in some text].
The RIAA network leads to that un-used 6C4, cap-coupled
through a selector switch for CD in and 50K pot to the
driver 6BQ5. The phono stage is a little marginal on
gain. Alone, I can play it WFO--but that's too loud if any-
one else is home. The phono section is wonderful on
tone, and texture. The sound is relaxed [that is very
important to me]. Enough detail. And quiet enough,
though there is some power supply and carbon comp
resistor noise barely audible with my good ear close to
the speaker [the Diatones].
Construction notes: I used separate power supply and
signal busses, of 12ga solid, like the later Sakuma
stuff. The signal buss is nailed to the chassis only
at the input jacks; the power supply and earth ground
near the main filter caps. WW's and carbon comps.
I'm using up my supply of ceramic standoffs I got from
that Japanese electron microscope but just found out
that Michael Percy now sells the same things. Good.
Mostly Aeon polypropylene/tin foil coupling caps, & just
Muses for bypasses. 3 good Tele 6BQ5, one Mullard, two
cheap cloudy no-name low-gain ones; a few different
6C4's, and a pair of pretty brown base Tungsol 6SU7
for the 6SL7's. Are these always so sweet?
There were/are compromises in this amp, based
on my own doubt that it would amount to anything.
An experiment, see how all this stuff would fit
together, see if I could juggle this many pieces.
Twelve-buck IT's, misused Hammond chokes, and
a junk-box power supply [though a nice junk-box
power supply]. Sakuma can't be blamed for anything
bad about this amp. But the tone is rich and clean
and nice. I think that this amp is a window to
Sakuma's intentions. And a nice shop amp.
--Carter
=========================================================================
From: Plaato <Plaato@aol.com>
Subject: Re: 6BQ5IT6BQ5PP
Date: Thu, 21 May 1998 23:16:31 EDT
Source: Sound Digest Archive v01.n288
Carter,
I built a similar amp last winter using a triode 6BQ5 driver, parafed AES It's
with a 20 henry Hammond choke and Ultra Linear Dyna ST35 OPT's . I like the
amp a lot and use it to drive some KLH 24's in the upstairs study. The amp is
a little weak in the bass, probably due to the AES tranies. did you find that
the 6BQ5 driver was microphonic? I bought some Svet SV83's and tried them in
the amp but they were more microphonic, prone to funny noises and not as good
sounding as NOS 6BQ5-EL84's.
Henry Platt
=========================================================================
From: Carter Hendricks <carterh@crl.com>
Subject: Re: 6BQ5IT6BQ5PP
Date: Fri, 22 May 1998 21:33:38 -0500
Source: Sound Digest Archive v01.n289
At 11:16 PM 5/21/98 EDT, Plaato wrote:
>Carter,
>I built a similar amp last winter using a triode 6BQ5 driver, parafed AES It's
>with a 20 henry Hammond choke and Ultra Linear Dyna ST35 OPT's . I like the
>amp a lot... The amp is a little weak in the bass, probably due to the AES
tranies.
Henry--
I'd look harder at that 20H choke than the toy nickel trannies.
>did you find that the 6BQ5 driver was microphonic?
Not the driver, but one of the junk tubes was a bit ringy and I had a 6C4 which
rang along with the music ugh. But the amp has been quiet and well-behaved...
--Carter
=========================================================================
From: Carter Hendricks <carterh@crl.com>
Subject: Re: 6BQ5IT6BQ5PP
Date: Sat, 23 May 1998 22:04:01 -0500
Source: Sound Digest Archive v01.n290
At 09:26 PM 5/21/98 -0500, Carter Hendricks wrote:
>So far I am using Hammond 30H 40mA power supply chokes
>as plate chokes. [I remember that Grover did something like
>this and when he upgraded to better inductors the highs
>improved. I have some slight glare across the overtones
>on the upper third of the piano keyboard... Is that glare
>the cheap choke, Grover?]. Can't wait to get some of
>Mikey's real plate chokes!
>
>{Note: I wrote this a couple weeks ago. The plate chokes
>have since arrived. So has the freshly-painted Fulvia HF.
>In cases like this, the shop wins. Upgrade/update, soon.}
OK: don't touch the two exposed wires right on the top.
They're hot, near 300 volts.
Which is to say that the Magnequest Brooklyn plate chokes
are in service. They're pretty, brass, but lacquered*, with
the same bolt centers as the old Hammonds but two bare
solder lugs on the top of each choke. Be careful, Anna!
Now the Hammonds are cool for testing/experimenting.
They do work as plate chokes, just fine. If there was more
of a substantial cost difference, one could be happy
enough forever.
[I think the Hammonds are about $20, the Magnequests $50]
But the Magnequest chokes are a -huge- improvement in
this amp. The piano glare is gone. Good enough. But the
trumpet sound [Harry Edison!] has opened up too. This amp
won't go back to the shop for a while!
--Carter
*ugh
=========================================================================
From: Carter Hendricks <carterh@crl.com>
Subject: Re: 6BQ5IT6BQ5PP
Date: Sat, 23 May 1998 22:13:39 -0500
Source: Sound Digest Archive v01.n290
At 11:16 PM 5/21/98 EDT, Plaato wrote:
>Carter,
>I built a similar amp last winter using a triode 6BQ5 driver, parafed AES It's
>with a 20 henry Hammond choke... The amp is a little weak in the bass...
More on the bass... For me bass is the Bass in a jazz
recording, mostly. Mike Stephens came up from Dallas and
we listened for a couple hours [he hadn't heard the amp or
the Diatones before]. Listened to Ray Brown and to Charlie
Haden and the tone of the instruments is actually a lot clearer
with the new/real 30H plate chokes.
--Carter
=========================================================================
From: Grover Gardner <groverg@postoffice.att.net>
Subject: Re: 6BQ5IT6BQ5PP
Date: Sat, 23 May 1998 23:55:04 -0500
Source: Sound Digest Archive v01.n290
At 9:26 PM -0500 5/21/98, Carter Hendricks wrote:
>Cool part: the PP's and driver 6BQ5s are straight from
>Sakuma's design. I used the little nickel AES 10K:90K IT.
>I put a small cap in the ground leg like a good parafeeder.
>'Bought a couple of the IT's when others first talked about
>them, then set them aside after someone said that they
>measured awful. Maybe, but they seem to sound nice. I
>loaded them with resistors plus small 100K stereo pots wired
>as variable resistors. I've been playing with additional
>loading and a small bit seems to strengthen bass and tone.
>So far I am using Hammond 30H 40mA power supply chokes
>as plate chokes. [I remember that Grover did something like
>this and when he upgraded to better inductors the highs
>improved. I have some slight glare across the overtones
>on the upper third of the piano keyboard... Is that glare
>the cheap choke, Grover?]. Can't wait to get some of
>Mikey's real plate chokes!
Certainly real plate chokes will sound nicer. But also I use the slightly
larger 7K:15K interstage, which to my ears has a smoother tone. I also do
not load the secondaries. Have you tried removing the loading resistors?
Grover
=========================================================================
From: tronan@orion.it.luc.edu (Tom Ronan)
Subject: Re: 6BQ5IT6BQ5PP
Date: Tue, 26 May 1998 17:37:03 -0500
Source: Sound Digest Archive v01.n293
I have not yet gotten a chance to comment on Carter's "Sakuma-chan" as I
call it.
Carter has a knack for putting together these little circuits with class
and flair. He's "throwing them together", but they make the finished
products I turn out for myself look junky. He's got this little amp built
on a nice aluminum plate, and like his 26 preamp, the top plate is
separated from the bottom with standoffs. A bit reminiscent of Garber, but
more industrial looking.
The circuit is utterly simplistic, the driver stage a power tube like
Sakuma suggests. The IT is el crapo (the Nickle AES jobber), when I heard
the amp it had Hammond plate chokes (eeks), and a pair of Fisher 400 OPTs
(which _do_ have a nice tone, but are nothing super exotic). Kudos to
Carter on this one, becuase this amp is one of the best push-pull amps I've
ever heard. It had magic, like direct heated tubes have magic for me.
Skip the audiophile comments, because it wasn't very audiophile. It had
soul - and got down to the emotion of the music without fuss. The tone of
horns were very good, but the voices were ungodly wonderful. My one real
criticism of the amp was that it had a bit of bite, but from my experience
with not-so-great chokes, I attributed that to the Hammonds.
This little amp is a contender with a SE DHT. It has all the stuff I like
and doesn't give up much at all. It seemed to find with ease some of the
characteristics that I stuggle very much to pull out of a tube. It was
quiet, and not fussy, and could be built very inexpensively.
If you are vacillating as to what amp to build, bug Carter to help you with
this one and build it. More music here than any integrated I've heard,
better than any vintage push-pull using the tube and I love _those_ little
integrateds more than any of the others.
Good job!
Tom
- ------
Thomas Ronan tronan@orion.it.luc.edu
1045 W. Montana, Chicago, IL 60614 773.528.0882
Lowther-America, Chicago Representative
=========================================================================
From: Ed Johnson <rb1304@alltel.net>
Subject: 6bq5it6bq5pp
Date: Sat, 30 May 1998 23:09:45 -0400
Source: Sound Digest Archive v01.n297
Anyone have this circuit availible anywhere for the 6bq5it6bq5pp amp?
=========================================================================
From: "Doc B." <bottlehead@silverlink.net>
Subject: Re: 6bq5it6bq5pp
Date: Sun, 31 May 1998 08:13:23 -0700
Source: Sound Digest Archive v01.n297
>Carter pointed me to the original Sakuma circuit he based his on.
>http://www5.big.or.jp/~dh/work/82012.html
>
>Facinating site. Looks like over 100 circuits. All of them with more stages
>and way more iron than im used to seeing. (This is not a criticism, just a
>observation.) It's obivious that there is a lot of years of building -
>listening - building - listening going on here.
>
>The idea of build RIAA eq right into a power amp is cool. Lots of circuits
>where the output tube is driven by an IT driven by another output tube. ex.
>845 - IT - 845
Well, based on my experience listening to Sakuma san's amp, you might want
to listen to one before jumping in and building one of those 845 amps...it
has, shall we say, a unique sound.
An interesting exercise is to estimate the amount of wire the signal travels
through in Sakuma san's 845 amp. It works out such that the mile makes a
convenient unit of measure. We estimated 1.5 watts output at VSAC last year,
the low level most likely due to copper losses.
Interesting circuits, indeed.
Doc B.
=========================================================================
From: "Robert Clark" <rclark@insightinc.com>
Subject: RE: 6bq5it6bq5pp
Date: Sun, 31 May 1998 08:34:11 -0400
Source: Sound Digest Archive v01.n297
Carter pointed me to the original Sakuma circuit he based his on.
http://www5.big.or.jp/~dh/work/82012.html
Facinating site. Looks like over 100 circuits. All of them with more stages
and way more iron than im used to seeing. (This is not a criticism, just a
observation.) It's obivious that there is a lot of years of building -
listening - building - listening going on here.
The idea of build RIAA eq right into a power amp is cool. Lots of circuits
where the output tube is driven by an IT driven by another output tube. ex.
845 - IT - 845
- -----Original Message-----
From: owner-sound@lists.io.com [mailto:owner-sound@lists.io.com]On
Behalf Of Ed Johnson
Sent: Saturday, May 30, 1998 11:10 PM
To: sound@deliverator.io.com
Subject: 6bq5it6bq5pp
Anyone have this circuit availible anywhere for the 6bq5it6bq5pp amp?
=========================================================================
From: "Lynn T. Olson" <lynno@teleport.com>
Subject: Re: 6bq5it6bq5pp
Date: Sun, 31 May 1998 20:42:42 -0700
Source: Sound Digest Archive v01.n298
>Well, based on my experience listening to Sakuma san's amp, you might want
>to listen to one before jumping in and building one of those 845 amps...it
>has, shall we say, a unique sound.
>An interesting exercise is to estimate the amount of wire the signal travels
>through in Sakuma san's 845 amp. It works out such that the mile makes a
>convenient unit of measure. We estimated 1.5 watts output at VSAC last year,
>the low level most likely due to copper losses.
>Interesting circuits, indeed.
>
>Doc B.
My PP amp is inspired by the Sakuma circuit (with much encouragement from
Takuji), but with many detail changes (different driver tube, shunt reg
driver PS, etc). It sounds *totally* different than the Sakuma amps demo-ed
at the VSAC last year. I'd had my amps up and running for about two months
before I heard the Sakuma concert, and I was stunned at the difference.
Much of that I surmise was due to the narrowband Tamura iron ... I think
the input trans on some of the Sakuma amps has a quoted -3dB FR of 30Hz to
15kHz. However, for the kind of speakers Sakuma favors, the bandwidth
limitation might be just the thing to bring out the best in them ... no
point in shooting powerful ultrasonics at a Lowther, for example.
I guess it goes without saying that the iron has a *big* impact on the
resulting amp. If it's wideband, you get a wideband sound. Narrowband, you
get a more "mid-focussed" sound. This in turn depends on whether the
partnering speakers want a wideband or narrowband signal ... this depends
on how well the driver handles out-of-band signals, and whether or not the
out-of-band signal creates IM distortion elsewhere in the audio band.
I suspect the Sakuma amps sound different from each other, and have certain
speakers that are a good match for them ... the speakers shown in the
restaurant photos give a hint what Sakuma likes.
I keep being surprised out how transparent transformer coupling sounds ...
when Dan and John came visiting a while back, we compared the Jeff Rowland
preamp to the proto Xtreme preamp. Both preamps used trans coupling ...
input trans on the Rowland, and a parafeed output trans on the Xtreme
preamp. This added to the 3 trans in power amp made for no less the *four*
AF trans in the signal path. The sound? Very very transparent, moreso than
any direct-coupled transistor amp and preamp. Go figure.
We do get a hint from the fact that the Audio Precision test setup, with a
THD distortion residual of 0.00008% (not a misprint), does use a coupling
transformer on the analog output (probably a Jensen).
Lynn T. Olson
E-mail: lynno@teleport.com
Ariel Speaker Page: http://www.teleport.com/~lynno/Ariel.htm
=========================================================================
From: "Monosoff, Scott" <Monosoff#m#_Scott@mmac1.lmms.lmco.com>
Subject: 6bq5it6bq5pp
Date: Mon, 01 Jun 1998 18:33:39 -0800
Source: Sound Digest Archive v01.n299
Doc B wrote:
>Well, based on my experience listening to Sakuma san's amp, you might want
>to listen to one before jumping in and building one of those 845 amps...it
>has, shall we say, a unique sound.
Ok, Ok, I give up! I'll build one. I've got one of those little Japanese
Trio 6BQ5 integrated amps that I'm thinking of using as the basis.
But, if I can't squeeze the extra iron on that chassis...
Carter, would you share the RIAA network that you and John came up with?
TIA,
Scott
=========================================================================
From: "T. Loesch" <ezee_e@hotmail.com>
Subject: 6BX7 and 6DN7 - Data and where to buy
Date: Wed, 14 Oct 1998 04:06:01 PDT
Source: Sound Digest Archive v01.n453
Hi there,
Subject really says it all....
Doc B. might to be able to help out with the 6DN7....
Kind regards Thorsten.
======================================
e-mail:
Thorsten@tnt-audio.com
Visit TNT-Audio on the Web - the only advertising
free audio web-zine.
http://www.tnt-audio.com
======================================
______________________________________________________
Get Your Private, Free Email at http://www.hotmail.com
=========================================================================
From: "Doc B." <bottlehead@silverlink.net>
Subject: Re: 6BX7 and 6DN7 - Data and where to buy
Date: Wed, 14 Oct 1998 08:29:08 -0700
Source: Sound Digest Archive v01.n454
We published curves that Alan Douglas ran for the 6DN7 "big half" in April
96 VALVE.
Doc B.
www.bottlehead.com
- -----Original Message-----
From: T. Loesch <ezee_e@hotmail.com>
To: sound@deliverator.io.com <sound@deliverator.io.com>
Date: Wednesday, October 14, 1998 5:05 AM
Subject: 6BX7 and 6DN7 - Data and where to buy
>Hi there,
>
>Subject really says it all....
>
>Doc B. might to be able to help out with the 6DN7....
>
>Kind regards Thorsten.
>
>======================================
>e-mail:
>Thorsten@tnt-audio.com
>
>Visit TNT-Audio on the Web - the only advertising
>free audio web-zine.
>
>http://www.tnt-audio.com
>======================================
>
>
>______________________________________________________
>Get Your Private, Free Email at http://www.hotmail.com
>
=========================================================================
From: "T. Loesch" <ezee_e@hotmail.com>
Subject: Re: 6BX7 and 6DN7 - Data and where to buy
Date: Thu, 15 Oct 1998 07:51:44 PDT
Source: Sound Digest Archive v01.n455
Yo Paul,
>Try Black Art Audio, http://www.jeack.com.au/~lucas/ - they have some
>DN7 curves, and the link now works.
Cool Dude. ThanX.
I have gotten the basic Data from Russell and there is a little bit more
of little bit's and pieces all over the net.
>fwiw, the one 6DN7 I measured had a mu of 15.7 and a "nonlinearity
>factor" (my term, see the latest VALVE for details) of 0.166 - the
>300Bs I've measured the same way are all NLF = 0.11 approximately, so
>the DN7 is pretty good.
Very good. Sounds like the ideal Input/Driver for my 845 Amplifier
project. And given that there is already a 8-Pin socket (two actually -
but needs removing and drilling larger for the 845 socket) all falls
together nicely.
Maybe I'll put a C4S on the first Valve and direct-couple the the second
Section? That should work rather nicely....
Kind regards Thorsten.
======================================
e-mail:
Thorsten@tnt-audio.com
Visit TNT-Audio on the Web - the only advertising
free audio web-zine.
http://www.tnt-audio.com
======================================
______________________________________________________
Get Your Private, Free Email at http://www.hotmail.com
=========================================================================
From: Paul Joppa <pdj@ISDNseattle.net>
Subject: Re: 6BX7 and 6DN7 - Data and where to buy
Date: Thu, 15 Oct 1998 07:23:46 -0700
Source: Sound Digest Archive v01.n457
Try Black Art Audio, http://www.jeack.com.au/~lucas/ - they have some
DN7 curves, and the link now works. Look under "circuits"; it's at the
end. The constant-dissipation curves say 12 and 15 watt, but are
actually 8 and 10 watt. I think they took this data themselves as it
is not widely (at all?!) published.
fwiw, the one 6DN7 I measured had a mu of 15.7 and a "nonlinearity
factor" (my term, see the latest VALVE for details) of 0.166 - the
300Bs I've measured the same way are all NLF = 0.11 approximately, so
the DN7 is pretty good.
- -Paul Joppa
=========================================================================
From: Thomas Woodley <twoodley@freespace.net>
Subject: 6BX7 plate chart
Date: Mon, 30 Nov 1998 11:12:52 -0500 (EST)
Source: Sound Digest Archive v01.n509
Does anyone know of a tube manual that provides a plate chart for the
6BX7? My RCA and Sylvania manuals don't. Conversely, I seem to remember
mention of a web site with the 6Bx7 chart - could someone please provide
me with the address of this. Thanks in advance.
Thom.
=========================================================================
From: "blackie" <blackie@mail.infohouse.com>
Subject: 6C15pi in the sky
Date: Wed, 9 Dec 1998 07:29:25 +0000
Source: Sound Digest Archive v01.n530
Wow, I am truly surprised that you got a response from Mike Matthews
regarding this tube. But why should he grace me with a serious
response? I only spent $24000+ at New Sensor last year!
BTW I believe it was 6C45pi that I compared to 417a - I never got the
specs for 6C15pi, believing it to be a hopeless case after talking to
Mike. I will scan and post the sheets if anyone wants 'em. If you
still want the sheets for 6C15pi I'll get 'em from Otto and post 'em.
I am currently having a serious row w/ Matthews and company (an
unrelated matter)...I am looking for another wholesale supplier at
this moment.
blackie
blackie@tubesville.com
www.tubesville.com
=========================================================================
From: Simon Busbridge <S.C.Busbridge@bton.ac.uk>
Subject: 6C19C
Date: Wed, 29 Oct 1997 17:52:46 +0000 (GMT)
Source: Sound Digest Archive v01.n094
Hello all,
I came across this valve on the net - looks like a low mu regulator type.
Has anyone tried it for audio - any good? Who makes it?
Simon
Dr Simon Busbridge
University of Brighton
Lewes Road
Moulsecoomb
Brighton BN2 4GJ
UNITED KINGDOM
Tel: 0044 (0)1273 642542
Fax: 0044 (0)1273 642327
e-mail: s.c.busbridge@bton.ac.uk
"..biology is what you do when you don't have the maths for real
science.." (Sliders)
=========================================================================
From: "Richard A. Francis" <rfranci@uoft03.utoledo.edu>
Subject: 6CD6 vs EL509
Date: Mon, 26 Oct 1998 20:59:32 -0500 (EST)
Source: Sound Digest Archive v01.n469
Has anyone compared the specs for these tubes? The EL509 is listed with
plate diss of 34 watts, and draws 2A fil. current. The 6CD6, which is no
runt of a tube either, drawing 2.5 A fil. current, has PD of only 20
watts. If you look at the two tubes, the EL509 *does* have a taller
internal structure, but I'm still surprised at the difference in PD specs.
The RCA manual gives the EL509's 34 watts as "absolute maximum" PD, so
maybe they are not actually comparable. In which case the 6CD6 might
actually handle more like 30 on the same scale.
There was a McIntosh amp that used 6CD6s, though I don't have the
schematic. I've got these DuKane PA amps that claim 50 watts out of a
pair, and another that claims 100 watts out of 4. At 20 watts PD per tube,
that's some impressive efficiency! ;) Can anyone shed light on this?
I seem to be having trouble getting mail, so best if you could copy to
rfranci@uoft02.utoledo.edu
Thanks,
Rick
=========================================================================
From: "Bill Gaw" <whg@tiac.net>
Subject: 6dj8 types
Date: Thu, 31 Dec 1998 09:25:03 -0500
Source: Sound Digest Archive v01.n554
This is a multi-part message in MIME format.
- ------=_NextPart_000_0065_01BE349F.727A1380
Content-Type: text/plain;
charset="iso-8859-1"
Content-Transfer-Encoding: quoted-printable
Can anyone deswcribe the differences between the 6dj8, ecc88, =
e88cc,e188cc,6922, etc. Which can be used at the highest voltages and =
which brands of the different types have the lowest noise aznd highest =
musicality. Thanks. Bill
- ------=_NextPart_000_0065_01BE349F.727A1380
Content-Type: text/html;
charset="iso-8859-1"
Content-Transfer-Encoding: quoted-printable
<!DOCTYPE HTML PUBLIC "-//W3C//DTD W3 HTML//EN">
<HTML>
<HEAD>
<META content=3Dtext/html;charset=3Diso-8859-1 =
http-equiv=3DContent-Type>
<META content=3D'"MSHTML 4.72.3110.7"' name=3DGENERATOR>
</HEAD>
<BODY bgColor=3D#ffffff>
<DIV><FONT color=3D#000000 size=3D2>Can anyone deswcribe the differences =
between the=20
6dj8, ecc88, e88cc,e188cc,6922, etc. Which can be used at the highest =
voltages=20
and which brands of the different types have the lowest noise aznd =
highest=20
musicality. Thanks. Bill</FONT></DIV></BODY></HTML>
- ------=_NextPart_000_0065_01BE349F.727A1380--
=========================================================================
From: Thomas Danley <Tom@ppci.com>
Subject: Re: 6dj8 types
Date: Thu, 31 Dec 1998 10:55:33 -0600
Source: Sound Digest Archive v01.n554
Bill Gaw wrote:
> Can anyone deswcribe the differences between the 6dj8, ecc88,
> e88cc,e188cc,6922, etc. Which can be used at the highest voltages and
> which brands of the different types have the lowest noise aznd highest
> musicality. Thanks. Bill
>
Hi
I can tell you that the tube family has both strong proponents and
detractors and based on my playing with them, I would say they are very
linear IF run at a large ish current (stay well away from the region
around zero I). The 6DJ8 / ECC88 has a book transconductance of
12500, but so does the 6922 / E88CC.
On the other hand, an article in glass audio some years back listed the
6922 at about twice the transconductance and better linearity and in my
testing in identical circuits the 6922 has more gain.
The family 6DJ8 / 6922 is often used for low RF applications and where
linearity is required (most of mine have come from salvaged Tektronics
oscilloscopes, an application where the designers could have used any
tube available. I also have a 450lb (cost was no object then) Military
Short-wave Radio made in the 60's which has 66 tubes, some of the signal
tubes are 6922's.
If replacing a tube that had lower gain, one could increase the cathode
voltage compliance (increasing the cathode resistor) and de-generate the
stage gain. This is not to be confused with closed loop feedback, as
degeneration has NO side effects and is unconditionally stable. To the
degree you degenerate the gain, you also reduce any inherent tube non
linearity as the resistor is totally linear I = V. (like the way an air
gap in a transformer smoothes out permeability variations in the overall
circuit)
So far as musicality goes, I hear differences often especially working
on loudspeaker drivers but choosing which sounds more real is hard, too
often the choice changes with the recording or instruments.
Linearity on the other hand can be measured by equipment that is
impartial.
With an amplifier one can drive a system with a complex signal like
music, compare the input to the output and argue that (except for a
change in voltage level) a "perfect" amplifier has NO difference at all
between the input and output signals.
I assume the latter here, so I often design toward linearity using the
ratio of the input signal to the difference signal as the indicator of
improvement. This is done with a "null" test.
A simple "null" test can be constructed if your amplifier is signal
inverting.
Take a 20-50k pot, (easier if a 10 turn type) connect the signal source
to one side, load the amp with a suitable resistor and connect the
output hot connection to the other end of the pot through a 100K
resistor . Take a second amplifier and connect its input to the wiper on
the pot and output to a speaker or headphones.. Complete ground paths
between the amplifiers.
Adjust the pot to about the center and turn the amp under test on.
Confirm music comes out OK. Turn the second amp on gain turned low.
Using a scope, volt meter or ears, adjust the pot to the minimum signal
point, the "null".
The residual signal left on the pot's wiper is the "difference " between
the input and output which can be listened to on the speaker.
If the resistive load is replaced by a real speaker (best placed in
another room) the residual signal is much larger due to the reactive
components in the speaker shifting the phase some at various
frequencies.
Anyway a null test is interesting and useful, it lets you actually hear
the amp's error signal and does allow some fine tuning by ear.
Tom Danley
=========================================================================
From: Thomas Dunker <dunker@invalid.ed.unit.no>
Subject: Re: 6dj8 types
Date: Mon, 4 Jan 1999 19:20:20 +0100 (CET)
Source: Sound Digest Archive v01.n557
On Thu, 31 Dec 1998, Thomas Danley wrote:
> I can tell you that the tube family has both strong proponents and
> detractors and based on my playing with them, I would say they are very
> linear IF run at a large ish current (stay well away from the region
> around zero I). The 6DJ8 / ECC88 has a book transconductance of
> 12500, but so does the 6922 / E88CC.
Thanks, Tom. I sincerely hope we'll never have to read another "serious"
magazine article or Net posting about the dismal performance of these
tubes when operated at stupid low currents. I don't have a lot to add
except to say that the E188CC (and 7308) are rated for a slightly
higher plate dissipation than ECC88/E88CC/6DJ8/6922:
E88CC E188CC
Wa(max) one section 1.5W 1.65W
Wa(max) (total both sections) 2.0W 2.2W
Wa(max) for one section of the E88CC/6922 can be 1.8W providing that
total dissipation for both sections does not exceed 2.0W. For the
E188CC/7308 one section can have a dissipation of 2.0W providing that
total for both sections doesn't exceed 2.2W.
This doesn't make a lot of sense to me, but this is the info given by
Philips in the 1970 manual Part 3, "Special Quality Tubes, Miscellaneous
Devices).
There's an even bigger brother called E288CC/8223, not identical
to the other two in terms of the plate characteristic (which is not
supposed to differ at all between an E88CC/6922 and an E188CC/7308).
I have never played with this one but it looks nice for a twin
triode:
Heater: 6.3V/475mA
Ip: 30mA
gm: 20mA/V
mu: 25
Ri: 1.25 kohms
Req: 200 ohms (Equivalent noise resistance at RF)
Noise figure: 5.7 dB
Wa(max): 3W (one section)
The plate curves for the E288CC/8223 look more like those of the E182CC/
7119 and pretty good at high currents.
(the other) Tom D.
- -------------------------------------------------------------------------
_/\_ Thomas Dunker \ The Horn Speaker Home Page:
/ \ P.O.Box 2811 \ http://invalid.ed.ntnu.no/~dunker/horns.html
| | 7002 Trondheim \
| | NORWAY \--\ "Those with head above water
\____/ dunker@omegav.ntnu.no \ see only the tip of the iceberg"
|||| phone (+47)73916898 \ (Gene Dalby)
- ------------------------------------------------------------------------
=========================================================================
From: evaguido <EvaGuido@iaehv.nl>
Subject: Re: 6dj8 types
Date: Mon, 04 Jan 1999 20:48:46 +0100
Source: Sound Digest Archive v01.n557
>
> E88CC E188CC
>Wa(max) one section 1.5W 1.65W
>Wa(max) (total both sections) 2.0W 2.2W
188 has lower noise figure as well
> There's an even bigger brother called E288CC/8223, not identical
>to the other two in terms of the plate characteristic (which is not
>supposed to differ at all between an E88CC/6922 and an E188CC/7308).
> I have never played with this one but it looks nice for a twin
>triode:
>
>Heater: 6.3V/475mA
>Ip: 30mA
>gm: 20mA/V
>mu: 25
>Ri: 1.25 kohms
>Req: 200 ohms (Equivalent noise resistance at RF)
>Noise figure: 5.7 dB
>Wa(max): 3W (one section)
>
> The plate curves for the E288CC/8223 look more like those of the E182CC/
>7119 and pretty good at high currents.
Confirms my findings: This tubes starts to live at high currents !
Guido
>(the other) Tom D.
>
>-------------------------------------------------------------------------
> _/\_ Thomas Dunker \ The Horn Speaker Home Page:
>/ \ P.O.Box 2811 \ http://invalid.ed.ntnu.no/~dunker/horns.html
>| | 7002 Trondheim \
>| | NORWAY \--\ "Those with head above water
>\____/ dunker@omegav.ntnu.no \ see only the tip of the iceberg"
> |||| phone (+47)73916898 \ (Gene Dalby)
>------------------------------------------------------------------------
>
>
=========================================================================
From: Thomas Dunker <dunker@invalid.ed.unit.no>
Subject: Re: 6dj8 types - back on the air
Date: Mon, 4 Jan 1999 21:21:33 +0100 (CET)
Source: Sound Digest Archive v01.n557
Hey, does this mean I can finally post to JoeNet again?!?!?
I was thrown off the list before Christmas, resubscribed, and now
things seem to be working again.
Well, since only some of you have heard from me the past months
maybe I should let you all know what's been going on in my corner
of the world lately. I've kept reading JoeNet mail the whole time,
like I have for the past 4-something years, so it's not like I've
been "gone", really. I've taken a break from my studies (which never
seem to come to an end...) and currently work at a meat processing
plant here in Trondheim, where I process orders from restaurants,
hospitals, grocery stores etc. and send them whichever amount of
steaks, pork chops, diced beef, bratwurst or whatever they order.
Plain good old fashioned physical labor - no term paper deadlines,
exams or other worries that I have to take home with me in the
afternoon. Now that feels pretty good. Pay is pretty good too. My
father, who's been a schoolteacher for 25 years doesn't make THAT much
more (and I study to become, probably, a schoolteacher, sigh...).
Audio-wise I haven't really finished any big projects lately, but I'm
working on a really special line amp that Torbjoern designed around an
ancient little DHT (voltage gain) and some balanced transformers from
50's radio equipment.
I found out that nixie tubes are super cool and that I have to use some
for a decibel attenuation readout in my tubed electronic xovers to
simplify channel matching and for looks. Even had to import some Russian
TTL IC's (Russian equivalent to the obsolete 74141 nixie driver IC),
as these cost about 5% of what the NTE 74141 sells for at Mouser. Got
them directly from St. Petersburg thanks to this Swiss guy who deals
with Russian electronics.
If anyone knows a source of cheap nixie tubes, let me know, I'd like to
build up a lifetime supply. Also interested in "numitron" tubes and other
weird readout tubes. The decibel readout thing requires a
logarithmic amplifier and a suitable A/D converter plus some digital
junk to interface it with the nixies. Eventually there will be PCB
artwork etc. for the whole mess.
Finally got hold of a (mint) SME3012R arm for my Garrard 401. There will
be pictures. An article by the brilliant Reto Luigi Andreoli in the latest
issue of Hi-Fi Scene Schweiz has got me convinced that I must get hold of
a DL103 cartridge and I don't care what anyone says. I can even afford it.
My web pages are turning into World Wide cobWebs and I have to get a ton
of pictures scanned (bought a scanner the other day, so there's hope...),
links fixed etc.
Over here in Norway, signs of intelligent life appeared unexpectedly
at the domestic audio newsgroup no.audio some time around November.
This went on for some time, but now things are back to normal in there.
What happened was basically that someone started asking questions about
current driven speakers, and this made our "granddad", the
Norwegian loudspeaker hero Ragnar Lian write some really thought-provoking
posts, and he was eventually talked into giving a lecture at the
local chapter of AES in Oslo. A friend in Oslo kindly sent me a "bootleg"
tape recording of the lecture which I didn't have a chance to attend,
plus I have R. Lian's manuscript. I've already translated part of this stuff
and will repost here later. Lian inspires us to rethink 30+ years of
foolish speaker and amp design and I personally get a kick out of this
sort of stuff plus I keep trying to put these ideas to use in my system.
The more I learn about speakers, the more I realize what I have left to
learn and understand, but most importantly I realize how ignorant I've
been. The whole IDEA of how much we can actually improve our systems
by rethinking established "truths" (ie. misconceptions and ugly cost-
cutting "tricks"), using old knowledge and old (or better,
mature) technology is enough to fuel MY enthusiasm. Best of it all is
how Ragnar Lian, who worked in the consumer audio industry for decades,
now puts his finger on how this industry commits all kinds of sins
against well known truths, as when he refers to the Scan-Speak
drivers he designed in the 70's as "my old sins". All the remainder of
the industry does is brag about the amazing progress they're making.
Ha-ha! Well, I'm about to get a bit carried away here, so I'm gonna make
you read and enjoy, and hopefully think, for yourselves as I post my
translations of a couple of articles he posted to no.audio after I finish
this one. I URGE anyone interested in understanding speakers to read
what "granddad" has to say.
Later,
Tom D.
- -------------------------------------------------------------------------
_/\_ Thomas Dunker \ The Horn Speaker Home Page:
/ \ P.O.Box 2811 \ http://invalid.ed.ntnu.no/~dunker/horns.html
| | 7002 Trondheim \
| | NORWAY \--\ "Those with head above water
\____/ dunker@omegav.ntnu.no \ see only the tip of the iceberg"
|||| phone (+47)73916898 \ (Gene Dalby)
- ------------------------------------------------------------------------
=========================================================================
From: RICHARD JONES <RJ0101@Sprynet.Com>
Subject: 6DL4
Date: Sat, 12 Dec 1998 23:21:09 -0600
Source: Sound Digest Archive v01.n536
Does anyone have the 6DL4 curves and specs??
It looks an interesting tube and I want to use it as an input tube.
Thanks for any help....
Richard
=========================================================================
From: MRogerC <connl001@tc.umn.edu>
Subject: Re: 6DL4
Date: Mon, 14 Dec 1998 20:40:39 -0600
Source: Sound Digest Archive v01.n539
You can find it at:
http://www.wps.com/archives/tube-datasheets/index.html
RICHARD JONES wrote:
> Does anyone have the 6DL4 curves and specs??
>
> It looks an interesting tube and I want to use it as an input tube.
>
> Thanks for any help....
>
> Richard
=========================================================================
From: David Home <DHome@creo.com>
Subject: RE: 6DL4
Date: Tue, 15 Dec 1998 10:24:41 -0800
Source: Sound Digest Archive v01.n540
This tube is just half of a 6DJ8 is it not?
-----Original Message-----
From: MRogerC [mailto:connl001@tc.umn.edu]
Sent: Monday, December 14, 1998 6:41 PM
To: RICHARD JONES
Cc: sound@deliverator.io.com
Subject: Re: 6DL4
You can find it at:
http://www.wps.com/archives/tube-datasheets/index.html
RICHARD JONES wrote:
> Does anyone have the 6DL4 curves and specs??
>
> It looks an interesting tube and I want to use it as an
input tube.
>
> Thanks for any help....
>
> Richard
=========================================================================
From: David Home <DHome@creo.com>
Subject: RE: 6DL4
Date: Tue, 15 Dec 1998 12:55:24 -0800
Source: Sound Digest Archive v01.n540
Joe Curcio uses them in his FET/tube phono section. I have heard this amp,
but the tube is so completely merged with FETs on the cathode and the anode,
I find it impossible to name its sound in any way.
Regards, DAvid
-----Original Message-----
From: Grover Gardner [mailto:groverg@postoffice.att.net]
Sent: Tuesday, December 15, 1998 1:37 PM
To: David Home; 'MRogerC'; RICHARD JONES
Cc: sound@deliverator.io.com
Subject: RE: 6DL4
At 10:24 AM -0800 12/15/98, David Home wrote:
> This tube is just half of a 6DJ8 is it not?
> -----Original Message-----
> From: MRogerC [mailto:connl001@tc.umn.edu]
> Sent: Monday, December 14, 1998 6:41 PM
> To: RICHARD JONES
> Cc: sound@deliverator.io.com
> Subject: Re: 6DL4
Not at all, according to the specs--in fact I don't know of
anything else
quite like it. I'd never looked at this tube until Richard
kindly called
my attention to it over the phone. Maybe you could say it's
"twice" a
6DJ8...;-)
Grover Gardner
groverg@postoffice.att.net
=========================================================================
From: Grover Gardner <groverg@postoffice.att.net>
Subject: RE: 6DL4
Date: Tue, 15 Dec 1998 15:36:43 -0600
Source: Sound Digest Archive v01.n540
At 10:24 AM -0800 12/15/98, David Home wrote:
> This tube is just half of a 6DJ8 is it not?
> -----Original Message-----
> From: MRogerC [mailto:connl001@tc.umn.edu]
> Sent: Monday, December 14, 1998 6:41 PM
> To: RICHARD JONES
> Cc: sound@deliverator.io.com
> Subject: Re: 6DL4
Not at all, according to the specs--in fact I don't know of anything else
quite like it. I'd never looked at this tube until Richard kindly called
my attention to it over the phone. Maybe you could say it's "twice" a
6DJ8...;-)
Grover Gardner
groverg@postoffice.att.net
=========================================================================
From: "PEARL Cust Serv" <custserv@pearl-hifi.com>
Subject: Re: 6DL4...... What a find..
Date: Mon, 14 Dec 1998 21:43:34 -0700
Source: Sound Digest Archive v01.n539
God, I love the WWW. The URL given in the preceeding correspondence is
to a fascinating site. If you have a few minutes to idle away, check these
over:
http://www.wps.com/products/ede.html
http://www.wps.com/personal/black-hole/index.html
http://www.wps.com/archives/instruments/index.html
There are some very interesting OLD pieces of sota, hi-tech gear on
this page. Of particular interest to me was a GenRad, tuning-fork frequency
standard from the 50s. For what it's worth: few people are aware that Ampex
made a stabilized tuning-fork oscillator to drive a power amp that put out
110V/60Hz at enough current to drive the capstan motors in the famous
350-series of tape decks.. It was called a Model 350...
There are many good reasons why the Golden Age of American recording
was, indeed, golden...
Bill Perkins, PEARL Inc.
- ----------
>From: MRogerC <connl001@tc.umn.edu>
>To: RICHARD JONES <RJ0101@Sprynet.Com>
>Subject: Re: 6DL4
>Date: Mon, Dec 14, 1998, 7:40 PM
>
>You can find it at:
>
>http://www.wps.com/archives/tube-datasheets/index.html
>
>RICHARD JONES wrote:
>
>> Does anyone have the 6DL4 curves and specs??
>>
>> It looks an interesting tube and I want to use it as an input tube.
>>
>> Thanks for any help....
>>
>> Richard
>
>
>
=========================================================================
From: <dexter@seel.po.my>
Subject: 6DN7 equivalent..
Date: Mon, 22 Dec 1997 16:50:51
Source: Sound Digest Archive v01.n139
I need to know whether there is a substitute for 6DN7 valves..
regards..
dexter
SO MUCH TO DO WITH TUBES AND MUCH MORE FUN THAN SS!!!!!
LONG LIVE THE VALVE AND SO DO THE BOTTLEHEADS ON JOE-NET.
DEXTER PATRICK
SEEL ELECTRONIC ENG. SDN BHD
15B & 17B JLN. PETALING UTAMA 11
OFF JLN. KLANG LAMA
46000 PETALING JAYA, KUALA LUMPUR
MALAYSIA
TEL : 603 791 1573
603 791 1579
FAX: : 603 793 2308
=========================================================================
From: "Doc B." <bottlehead@silverlink.net>
Subject: 6ER5 idiocy, and a new phono preamp.
Date: Mon, 29 Jun 1998 17:44:30 -0700
Source: Sound Digest Archive v01.n328
This is a multi-part message in MIME format.
- ------=_NextPart_000_0015_01BDA385.91E31C40
Content-Type: text/plain;
charset="iso-8859-1"
Content-Transfer-Encoding: quoted-printable
So I take a break from my mess last night, come back to it this morning =
and immediately realize that the dumb 6ER5 heaters are in series, and =
were getting only 3.15 v each. Duh...
Anyway, threw some C4S loads on top of 6ER5s, running at about 200V, =
10mA, -1.2Vg, one 6ER5 on each side of George Wright's passive RIAA (to =
be redone when this whole deal goes in a new box).=20
Power supply ustabea Wright preamp supply, now fast/soft rectifiers on =
both B+ and heater supply, C-L-C (10 mfd, 8H, 500mfd) to a VR shunt =
regulator. Nice and quiet, even WOT, save for some rushing from one of =
my less than pristine 6ER5s. Will get a bigger power trans and discrete =
regs for each channel soon. This phono pre runs into my C4S loaded 5670 =
parafeed line stage, right off the second 6ER5 thru a .47 mfd Siderial =
cap, no cathode followers or nuthin'.
The gain with the C4S loads is good enough (about 80 each stage) that I =
am running a .5mV Koetsu without the so-so Denon step-up transformer I =
used to need. It's smokin' with a 2mV Audioquest AQ-404.
This is way good, I mean , sure, I've been missing the analog sound so =
maybe I'm just soaking up the smooth, but I wasn't getting it like this =
before, very speedy and dynamic. Still need to dial the RIAA, I'm sure. =
Will study some articles before diving in.=20
According to Tucker, this should have quite a bit better perceived bass =
response than that ultra cool Allen Wright Phono stage in SP #15.
Doc B.
VALVE
coming soon - www.bottlehead.com
- ------=_NextPart_000_0015_01BDA385.91E31C40
Content-Type: text/html;
charset="iso-8859-1"
Content-Transfer-Encoding: quoted-printable
<!DOCTYPE HTML PUBLIC "-//W3C//DTD W3 HTML//EN">
<HTML>
<HEAD>
<META content=3Dtext/html;charset=3Diso-8859-1 =
http-equiv=3DContent-Type>
<META content=3D'"MSHTML 4.72.2106.6"' name=3DGENERATOR>
</HEAD>
<BODY bgColor=3D#ffffff>
<DIV><FONT color=3D#000000 face=3D"Footlight MT Light">So I take a break =
from my=20
mess last night, come back to it this morning and immediately realize =
that the=20
dumb 6ER5 heaters are in series, and were getting only 3.15 v each.=20
Duh...</FONT></DIV>
<DIV><FONT color=3D#000000 face=3D"Footlight MT =
Light"></FONT> </DIV>
<DIV><FONT face=3D"Footlight MT Light">Anyway, threw some C4S loads on =
top of=20
6ER5s, running at about 200V, 10mA, -1.2Vg, one 6ER5 on each side of =
George=20
Wright's passive RIAA (to be redone when this whole deal goes in a new =
box).=20
</FONT></DIV>
<DIV><FONT face=3D"Footlight MT Light">Power supply ustabea Wright =
preamp supply,=20
now fast/soft rectifiers on both B+ and heater supply, C-L-C (10 mfd, =
8H,=20
500mfd) to a VR shunt regulator. Nice and quiet, even WOT, save for some =
rushing=20
from one of my less than pristine 6ER5s. Will get a bigger power trans =
and=20
discrete regs for each channel soon. This phono pre runs into my C4S =
loaded 5670=20
parafeed line stage, right off the second 6ER5 thru a .47 mfd Siderial =
cap, no=20
cathode followers or nuthin'.</FONT></DIV>
<DIV><FONT face=3D"Footlight MT Light">The gain with the C4S loads is =
good enough=20
(about 80 each stage) that I am running a .5mV Koetsu without the so-so =
Denon=20
step-up transformer I used to need. It's smokin' with a 2mV Audioquest=20
AQ-404.</FONT></DIV>
<DIV><FONT face=3D"Footlight MT Light">This is way good, I mean , sure, =
I've been=20
missing the analog sound so maybe I'm just soaking up the smooth, but I =
wasn't=20
getting it like this before, very speedy and dynamic. Still need to dial =
the=20
RIAA, I'm sure. Will study some articles before diving in. </FONT></DIV>
<DIV><FONT face=3D"Footlight MT Light">According to Tucker, this should =
have quite=20
a bit better perceived bass response than that ultra cool Allen Wright =
Phono=20
stage in SP #15.</FONT></DIV>
<DIV><FONT face=3D"Footlight MT Light"></FONT> </DIV>
<DIV><FONT color=3D#000000 face=3D"Footlight MT Light">Doc =
B.<BR>VALVE<BR>coming=20
soon - <A=20
href=3D"http://www.bottlehead.com">www.bottlehead.com</A></FONT></DIV></B=
ODY></HTML>
- ------=_NextPart_000_0015_01BDA385.91E31C40--
=========================================================================
From: "Aaron Bohnen" <bohnen@mail.unixg.ubc.ca>
Subject: Re: 6EU6 tube?
Date: Fri, 30 Jan 1998 00:58:57 +0000
Source: Sound Digest Archive v01.n176
Hi Steve,
About your inquiry:
> Is there anything special about the 6EU6 tube as a preamp tube? I was
> just wondering because I came across an integrated amp that uses them
> and I haven't seen them used this way before. Does the 6EU6 have an
> alternate 4 digit number? Anybody know?
A 6EU7 is essentially a differently-wired 12AX7. Not much really
inspiring about it.
best regards,
Aaron
___________________________________________________________
Aaron Bohnen, B.A.Sc., E.I.T. email: bohnen@unixg.ubc.ca
- -Ph.D. Candidate, Civil Engineering Department, U.B.C.
- -Technicraft Engineering Services
=========================================================================
From: Steve Van Osdell <svanos@toast.net>
Subject: 6EU6 tube?
Date: Fri, 30 Jan 1998 01:55:41 -0600
Source: Sound Digest Archive v01.n176
Is there anything special about the 6EU6 tube as a preamp tube? I was just
wondering because I came across an integrated amp that uses them and I
haven't seen them used this way before. Does the 6EU6 have an alternate 4
digit number? Anybody know?
Thanks, Steve
=========================================================================
From: Jonathan Morrison <ppdiva@pipeline.com>
Subject: 6gk5 was: Re: SJS phono section
Date: Sat, 25 Oct 1997 11:22:37 -0700
Source: Sound Digest Archive v01.n086
At 10:41 PM 10/24/97 -0700, you wrote:
>The Loesch design uses the 417A as well. Plus the Russians are
>not making 6GK5s to my knowledge.
There is a large group of similar triodes to the 6gk5, w/high mu, high Gm,
and frame grid- 6ha5, 6hm5(I think), 6hq5- some of these are stamped with
several #'s. I see them for cheap at several dealers. Anybody tried them?
While we're on the subject, has anybody tried the 6dl4? I tried a PP line
stage with them once and it seemed to work pretty well, but that was my
only experience. I was attracted to it because of the structure inside- it
looked like it would be very rigid.
While we're still on the subject, several people lately have criticized
6dj8's. Did you see Roger Modjeski's article in GA saying that a number of
6dj8's that he had taken apart were relabeled 6es8's- a similar tube but
variable-mu. I noticed in rec.audio.tubes recently that someone was selling
6es8's as a sub for 6dj8's. JDM
=========================================================================
From: RALPH POWER <POWER.RALPH@epamail.epa.gov>
Subject: 6L5G triode
Date: Wed, 14 Oct 1998 16:09:56 -0400
Source: Sound Digest Archive v01.n454
Hi All,
Is anyone familiar with the 6L5G, an octal based, ST shaped triode ?
Has anyone used it for a driver tube or in a preamp ?
Welborne Labs has them on sale for $3 each, so I bought a a pair to try.
Thanks for any info,
- Ralph
=========================================================================
From: "Peter Clark" <ReverendClark@worldnet.att.net>
Subject: Re: 6L5G triode
Date: Wed, 14 Oct 1998 18:25:29 -0700
Source: Sound Digest Archive v01.n454
- -----Original Message-----
From: RALPH POWER <POWER.RALPH@epamail.epa.gov>
To: sound@deliverator.io.com <sound@deliverator.io.com>
Date: Wednesday, October 14, 1998 1:40 PM
Subject: 6L5G triode
>
>Hi All,
>
>Is anyone familiar with the 6L5G, an octal based, ST shaped triode ?
>
>Has anyone used it for a driver tube or in a preamp ?
>
>Welborne Labs has them on sale for $3 each, so I bought a a pair to try.
>
>Thanks for any info,
>
> - Ralph
>
I use them as a driver in a push-pull triode wired 807 amp.
Characteristically they're the warm, rich tube sound that some strive for.
The brands, however, vary wildly, Sylvanias are the above in spades,
National Unions less so and my personal faves, Tung Sols, the tightest of
the lot. They are not particularly detailed sounding, as an impression, but
I think this is because of the well populated lower register. They're
killer on stuff like doo-wop, what many might think of as a "vintage" sound;
which, of course, it's not. Enjoy.
Regards,
Peter Clark
=========================================================================
From: SHAMSUL Bahrin Kamarudin <shamsul.BK@innosabah.com.my>
Subject: 6L6 valve amp good ?
Date: Fri, 14 Aug 1998 12:49:41 +0800
Source: Sound Digest Archive v01.n388
Hello.
Just would like to know is a 6L6 PP valve amp any good ?
Regards.
::-)
\\\///
/ _ _ \
(| (.)(.) |)
|--------.OOOo--()--oOOO.----------------------------------------|
mailto:shamsul.BK@innosabah.com.my
mailto:0198107360@sms.celcom.com.my
_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/
_/ H/P: 019-8107360 TEL: 6088-244185 FAX: 6088-251679 _/
_/ http://www.innosabah.com.my _/
_/ ======================================================== _/
_/ TO BECOME A LEADING HI-TECH, PEOPLE ORIENTED FINANCIAL _/
_/ SERVICES COMPANY WHICH OFFERS WORLD CLASS _/
_/ INNOVATIVE PRODUCTS AND SERVICES _/
_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/
_/ THIS IS A | INNOSABAH SECURITIES SDN BHD (194990-K) _/
_/ COMPUTER GENERATED | 11 EQUITY HOUSE, BLOCK K, _/
_/ ELECTRONIC MAIL | SADONG JAYA, KARAMUNSING, _/
_/ AND IS DEEMED TO | 88100 KOTA KINABALU, SABAH, _/
_/ HAVE BEEN SIGNED | M A L A Y S I A _/
_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/
=========================================================================
From: Grover Gardner <groverg@postoffice.att.net>
Subject: Re: 6L6 valve amp good ?
Date: Tue, 18 Aug 1998 22:48:04 -0500
Source: Sound Digest Archive v01.n395
At 12:49 PM +0800 8/14/98, SHAMSUL Bahrin Kamarudin wrote:
>Hello.
>
>Just would like to know is a 6L6 PP valve amp any good ?
Depends on what and which. Sure, a 6L6 amp can be very nice, in pentode or
a la Williamson, in triode mode. Decent power, good sound, easy to drive,
commonly available tube stock. Are you thinking of buying or building one?
Grover Gardner
groverg@postoffice.att.net
=========================================================================
From: SHAMSUL Bahrin Kamarudin <shamsul.BK@innosabah.com.my>
Subject: Re:>Re: 6L6 valve amp good ?
Date: Wed, 19 Aug 1998 11:44:25 +0800
Source: Sound Digest Archive v01.n395
*** Grover Gardner on 18/08/1998 around 10:48 PM -0500 wrote ..........
- ->At 12:49 PM +0800 8/14/98, SHAMSUL Bahrin Kamarudin wrote:
- ->>Hello.
- ->>
- ->>Just would like to know is a 6L6 PP valve amp any good ?
- ->
- ->Depends on what and which. Sure, a 6L6 amp can be very nice, in pentode or
- ->a la Williamson, in triode mode. Decent power, good sound, easy to drive,
- ->commonly available tube stock. Are you thinking of buying or building one?
- ->
- ->
I actually owned a unit, the Rogers E-40a valve amp. Was wondering if its
possible for me to modify and further enchance it, maybe soon as I gather
enough money to change them coupling caps etc that comes on the amp.
A few Joenetters contacted me and I appreciate thier comments & advices etc.
Regards.
::-)
\\\///
/ _ _ \
(| (.)(.) |)
|--------.OOOo--()--oOOO.----------------------------------------|
mailto:shamsul.BK@innosabah.com.my
_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/
_/ H/P: 019-8107360 TEL: 6088-244185 FAX: 6088-251679 _/
_/ http://www.innosabah.com.my _/
_/ ======================================================== _/
_/ TO BECOME A LEADING HI-TECH, PEOPLE ORIENTED FINANCIAL _/
_/ SERVICES COMPANY WHICH OFFERS WORLD CLASS _/
_/ INNOVATIVE PRODUCTS AND SERVICES _/
_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/
_/ THIS IS A | INNOSABAH SECURITIES SDN BHD (194990-K) _/
_/ COMPUTER GENERATED | 11 EQUITY HOUSE, BLOCK K, _/
_/ ELECTRONIC MAIL | SADONG JAYA, KARAMUNSING, _/
_/ AND