Go Back   Home > Forums > Amplifiers > Pass Labs

Pass Labs This forum is dedicated to Pass Labs discussion.

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 1st July 2002, 03:04 PM   #1
diyAudio Member
 
macka's Avatar
 
Join Date: Dec 2001
Location: Australia
Default Zen Balanced Line Stage Balanced vs Unbalanced

I have recently been trialing my new Balanced Line Stage in either balanced or unbalanced output to the Aleph 5.

Firstly, I have to say this is the best sounding pre I've heard for some time. Its quite a smart performer.

Why I did not build this ages ago is beyond me. Cheers Nelson.

Unbalanced in/out appears to sound a bit warmer, and unbalanced in/balanced output less warm and more crisp and clinical in comparison.

I maybe correct in assuming balanced output mode cancels some of the second harmonic disortion of SE operation?

I prefer a bit of 2nd harmonic maybe

As to my choice of parts its straight out of the article.

I'm using an Allen Bradley conductive plastic 25K dual gang pot on the input (unbalanced input mode) and the shunt attenuator (Aleph P) using (2) Lorlin 2 pole 6 position rotory switches with resisitors of 4.3K, 2K, 1K, 499R, 240R 120R.

This seems to work and does not appear to effect sound quality.

I intend to build Panos's relay version of the attenuator for 64 step multi stepped attenuation.

My output caps are Black Gate C series 10uf 50 volt, they are billiant!

regards

macka
  Reply With Quote
Old 1st July 2002, 03:24 PM   #2
nar is offline nar
diyAudio Member
 
nar's Avatar
 
Join Date: Apr 2002
Location: near the sea
You're right,it's a wonderful sounding unit.
Why not try some SCR capacitors for the output?I realized 2 versions of the ZLS,one with SCR capacitors and one with Arcotronics film cap grey version.I much prefer the SCR version than the other...
Some Blackgate types are not for coupling use.But I guess the Silmic silk separator series is OK for the purpose,and we can find some special for coupling use Blackgates.I would use a small MKP decoupling cap parallel however.

Regards
__________________
"... Audio needs the thinnest wire ..." Rowan McCombe ... I hear it !!!
"Just 'cause they can't hear or sense it themselves doesn't mean you can't !" Allen Wright Allen was right ...
  Reply With Quote
Old 1st July 2002, 05:26 PM   #3
Banned
 
Join Date: Apr 2002
Location: Germany, Clausthal
is there any difference in sound between balanced line stage and aleph p first version? which?
  Reply With Quote
Old 3rd July 2002, 03:42 PM   #4
nar is offline nar
diyAudio Member
 
nar's Avatar
 
Join Date: Apr 2002
Location: near the sea
Might be some-I think logically,P should have better bottom bass control than ZLS-but should be a little more "smokey"in medium and treble region ...

Nelson would tell...
__________________
"... Audio needs the thinnest wire ..." Rowan McCombe ... I hear it !!!
"Just 'cause they can't hear or sense it themselves doesn't mean you can't !" Allen Wright Allen was right ...
  Reply With Quote
Old 3rd July 2002, 09:11 PM   #5
The one and only
 
Nelson Pass's Avatar
 
Join Date: Mar 2001
Depends. The early P used big devices, and was slightly
darker at the top compared to later product which used
smaller chip sizes. They don't sound identical, but it's
strictly a matter of taste, and I never did develop a preference.
  Reply With Quote
Old 3rd July 2002, 09:19 PM   #6
Banned
 
Join Date: Apr 2002
Location: Germany, Clausthal
so its not the question if balanced line stage OR aleph p to build, only a question of taste, or the kind of devices laying around on the bench?
  Reply With Quote
Old 4th July 2002, 01:36 PM   #7
diyAudio Member
 
macka's Avatar
 
Join Date: Dec 2001
Location: Australia
This is interesting but the BOSOZ is a much simpler design than the Aleph P and the extra complexity hardy seems warranted.

A quick question for Nelson.

The idea of the shunt relay driven volume network like the P is appealing for means of construction and precision rather than say two 5K dual gang pots.

Do you consider any performance penalities over the 5 K pot other than reduced voltage swing?

**************************************

I've since arranged proper cannon leads and terminations for the pre and power amp with the input - negative shorted on the input of the pre amps.

I trust this is the correct way to run the pre with unbalanced inputs.

To my ears the sound is quite clean and dynamic.

regards

macka
  Reply With Quote
Old 8th July 2002, 06:52 PM   #8
The one and only
 
Nelson Pass's Avatar
 
Join Date: Mar 2001
5K takes the maximum output down a decibel or so,
but there is plenty of swing available.
  Reply With Quote
Old 8th July 2002, 07:57 PM   #9
diyAudio Member
 
Join Date: May 2002
Location: Cambridge, UK
Default BOSOZ, Alephp, etc.

I guess the obvious question is how different does the AlephP 1.7 sound given the added complexity and the addition of SuSy. For that matter, how does this differ both in implementation and sound from current X product? Okay, I know I am trying it on somewhat but I would genuinely like to know.

Ian.
  Reply With Quote
Old 8th July 2002, 09:30 PM   #10
diyAudio Member
 
macka's Avatar
 
Join Date: Dec 2001
Location: Australia
Ian,

This a good question so why not just ask for an A/B on the factory floor during lunch hour!

I suppose this is what diy is all about though, you have to make it to find out.

But from what I can see the P 1.7 is a commercial offering designed operate in either balanced/unbalance mode without any penalties referring to "optimal operation" in either mode according to the manual.

I think this refers to the additional components for best common mode rejection with unbalanced in/ and say balanced out.

However, the inherant SE operation appears in both designs so on paper one could only assume subjectively they would be slightly different but not major league, ie using fet current sources, input cap etc.

I'm still not sure why, but un bal in, unbal out sounds noticably different to unbal in , balanced out and would like to hear from the others if they have similar experience?.

The mids are cooler and recessed, the bass is much tighter and the top end is more agressive.

Perhaps I have a diy cremlin in there some where

regards

macka
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Balanced input stage beneficial for unbalanced turntables? leadbelly Analogue Source 37 28th April 2008 01:34 PM
Line input transformer for unbalanced to balanced conversion okapi Chip Amps 23 12th January 2008 05:29 PM
Unbalanced to Balanced Line Level XFMR wrenchone Solid State 8 22nd October 2005 08:06 PM
Balanced Zen v5 + balanced Zen line stage Adrie Pass Labs 0 30th May 2004 05:27 PM
Balanced line stage, quistion's + unbalanced lykkedk Pass Labs 4 19th December 2002 11:58 PM


New To Site? Need Help?

All times are GMT. The time now is 01:09 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2