Tim Reese's Generic Home Page

Sound Practices Mailing List Files - Volume 1


=========================================================================
From: "Doc B." <bottlehead@silverlink.net>
Subject: Re: X-Dac 3.0
Date: Tue, 1 Dec 1998 07:35:31 -0800
Source: Sound Digest Archive v01.n511

Love it.
Mine was built from the "board and parts" kit, has a few tweaks by Tucker
(shunt regulated DAC and a BG cap here and there), comes directly off the
DAC chip to the input of my line stage, and has a toroidal power trans
feeding a CLCLC PS going into three pin pregulators. It's superb, my only
beef as of late is that it's a bit noisy in the inverted mode, but this is
more likely due to constructor brain damage than a design flaw.

Doc B.
www.bottlehead.com
- -----Original Message-----
From: Christian Rintelen <rintelen@datacomm.ch>
To: Joenet <sound@lists.io.com>
Date: Tuesday, December 01, 1998 1:58 AM
Subject: X-Dac 3.0


>Joes,
>
>do any of you have experience with Norman Tracy's X-Dac 3.0? (I need a
>new DAC and his concept looks good.)
>
>TIA for your 2 cents
>
>Christian
>


=========================================================================
From: Christian Rintelen <rintelen@datacomm.ch>
Subject: X-Dac 3.0
Date: Tue, 01 Dec 1998 10:16:16 +0100
Source: Sound Digest Archive v01.n511

Joes,

do any of you have experience with Norman Tracy's X-Dac 3.0? (I need a
new DAC and his concept looks good.)

TIA for your 2 cents

Christian


=========================================================================
From: "Thorsten \"EZEE\" Loesch" <tloesh_2@globalnet.co.uk>
Subject: X-Former (Mains) Question
Date: Fri, 29 Aug 1997 11:20:58 +0100
Source: Sound Digest Archive v01.n004

Hi all,

While this is not strictly Glassbottle Audio, I'm trying 
to find a source for Toroidial Mains Transformers (with 
UK/European primaries). 

Now that in itself is no problem, the problem is that all 
X-Formers I have found so far are "low-profile" units which 
are comparatively large in diameter but not very high.

I cannot uses these unfortunatly, as the Units will have to 
fit into pre-allocated Spaces. In a number of comercially 
made Electronics I have seen "tall" Toroidial High Power 
transformers. these are usually about as high as they are 
wide. 

Does anyone know any source at all for these?

Kind regards Thorsten.

======================================
e-mail:
Torsten.Loesch@enhar-ha.nthames.nhs.uk

Disclaimer: The opinions expressed herin 
are my personal ones and do not in any 
way reflect opinions or policies of my 
employer.

web-pages:
http://www.users.globalnet.co.uk/~tloesh_2
======================================


=========================================================================
From: Jeremy Epstein <jepstein@shwd.com>
Subject: Xmas without tubes
Date: Wed, 23 Dec 1998 14:33:06 -0500
Source: Sound Digest Archive v01.n550

I need help, Joes!

You have all indulgently heard at great length my saga of building, and
experimenting with, a "Bob Danielak Darling" 1626 pushpull stereo amp.
Bob kept suggesting I listen to it single-ended, which I hadn't liked
given an unfair trial (ripply power supply, and using only half the IT
secondary and OPT primary windings : basically just pulling a tube from
each channel.)

I gave it a fairer trial (thanks to Ronan the Barbarian for the nice 8H
choke!) by rebuilding the power supply and rewiring the trannies
properly. Using one 1626 per channel, it was a little light in the
loafers, but parallel single-ended, that was the ticket.

It sounded great. But it was built into a disgusting messy salvaged
chassis. I made the decision to transfer it over onto a nice brass
chassis (remember those door kickplates I had mentioned here?) so it
would look nifty for the guests who are coming on Christmas Day, solely
to listen to my stereo. And to eat and to drink and to be merry, too, I
guess.

The new layout, the identical circuit to the setup I was enjoying so
much, motorboats like crazy. The key differences between the two
versions are as follows : the new one has a much more dense layout, also
components are on one turret strip instead of distributed to terminal
strips at different points, also IT and OP transformers are under the
top plate instead of atop it, also the 1626's for each channel are
mounted in the same orientation instead of being perpendicular to each
other.

It LOOKS a whole lot nicer, even without the woodwork for the base.

With the guests coming soon and my wife losing patience, where do I look
first? I was going to try reorienting the trannies first, then maybe
putting them on top.

As a troubleshooting indication, the motorboating stops when I touch a
1626, but even when it's not audible during silence, it modulates the
signal and sounds like real garbage. I have already tried the following
: seperating the power stage grounds from the driver stage ground,
resoldering the 1626's socket's pins, connecting the 12V heater center
tap to ground, reconnecting it back to the cathode of one set of 1626's,
moving the cathode bypass caps for the power tubes further away from the
driver's cathode resistors/caps, moving the plate supply wires around.
It seems to be slightly worse than when I started. @#$%%^&!

Help! I don't want to have to rig up my solid state amp for Christmas,
for Pete's sake (and Christ's!)

- -j
- -- 
=====================================
Jeremy Epstein .... jepstein@shwd.com 
=====================================


=========================================================================
From: Grover Gardner <groverg@postoffice.att.net>
Subject: Re: Xmas without tubes
Date: Wed, 23 Dec 1998 17:19:38 -0600
Source: Sound Digest Archive v01.n550

I would suggest you check the following:

Ground connections and scheme.
B+ supply--by any chance did you hook up the input and output stages out of
order in the B+ chain?
Do you have a shared B+ supply between the two channels?  Try more
decoupling in the PS.  This assumes you have adequate decoupling to begin
with.
Try disconnecting one channel from the power supply at a time and see if
one or the other motorboats on its own.
Check all your caps, including bypasses, for correct polarity.

I wonder if the brass plating is preventing a secure connection to ground.
You might scrape some off around your ground points (should be at the input
only, right?) and see if this helps.

Keep us posted.

Grover Gardner
groverg@postoffice.att.net


=========================================================================
From: andre@indigo.ie (Andre Jute)
Subject: XO points for voice matching
Date: Tue, 30 Sep 1997 12:42:11 +0100 (BST)
Source: Sound Digest Archive v01.n049

At 11:57 pm 29/9/97, GREGORY MONFORT wrote:
> I personally don't want the subs to play into the
>vocal range as deep bass will 'color' voicing when played at 'live' levels.

Gregory, if you could reach out and take speakers of ideal spec off the
shelf to match your idea of how music should sound, where would you choose
to cross over from sub to woofer, from woofer to mid, from mid to tweeter?

Andre

Andre Jute
andre@indigo.ie
Communication Jute

the main index to the pages we support for lovers of classical music, for
writers,  and for audiophiles is at

http://www.foundmark.com/ComJute/ComJuteF1.html


=========================================================================
From: "GREGORY MONFORT" <WINGRACER@classic.msn.com>
Subject: RE: XO points for voice matching
Date: Tue, 30 Sep 97 13:06:12 UT
Source: Sound Digest Archive v01.n049

I'm pleased with my system's active crossover points of 80 hz @ 18 db/octave, 
500 hz @ 12 db/octave, 5000 hz @ 6 db/octave.

GM 

- ----------


Gregory, if you could reach out and take speakers of ideal spec off the
shelf to match your idea of how music should sound, where would you choose
to cross over from sub to woofer, from woofer to mid, from mid to tweeter?

Andre


=========================================================================
From: "blackie" <blackie@mail.infohouse.com>
Subject: Re: xxxxxxxxxxxxxxxxx
Date: Wed, 15 Apr 1998 07:04:09 +0000
Source: Sound Digest Archive v01.n252

> Date:          Wed, 15 Apr 1998 08:14:38 -0500
> To:            "blackie" <blackie@mail.infohouse.com>
> From:          bill gardner <wg44929@navix.net>

> >                        Hi Blackie , what it is , welcome . I'm the guy JC
> warned you about , just kidden .
>                                          Best regards   Bill Gardner

Hey Bill

Just tryin' to get the scoop on this list type stuff
Hope you found my first post informative, har har

L8R

Blackie
blackie@tubesville.com

Tim Reese
reese@nmr.mgh.harvard.edu
MGH NMR Center
Charlestown Navy Yard
13th Street, Bldg 149 (2301)
Boston MA 02129