Zen Linestages, X and unbalanced operation - diyAudio
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 25th May 2003, 07:11 PM   #1
diyAudio Member
 
Join Date: May 2002
Location: Cambridge, MA, USA
Send a message via AIM to Kilentra
Default Zen Linestages, X and unbalanced operation

I admit a relative lack of understanding about balanced operation and X-feedback, so I'll ask a quick question: What is the usefulness of a "balanced" preamplifier when using single-ended connections for both input and output... and what would I have to do to a balanced circuit to get it to work that way (for the time being)?

See, I'm looking to build a good preamp, but at the moment I have unbalanced sources (CD player/DAC) and unbalanced-input amplifiers (Zen V4 and/or Holton's sym amp). Keeping my choices to Pass circuits at the moment, the BOSOZ seems to have a better reputation than the unbalanced-only BOZ... and now some of us have added "X" to that circuit. Will the BLS or X-BOSOZ work if I ground the unused input and leave the unused output disconnected? I could also load the unused output with something similar to the amp's input network, if that would help with the feedback. Even if it does work, does this waste the advantage of balanced operation? What about X, is is pointless trying to use that?

Thanks for the help.
  Reply With Quote
Old 26th May 2003, 06:50 AM   #2
Henrik is offline Henrik  Denmark
diyAudio Member
 
Join Date: Feb 2002
Location: Copenhagen Denmark
My advise to you is to build the BOSOZ, as long as you are driving it single ended at both input and output. But if you gets an balanced power amp, the you can X the BOSOZ, it´s an easy task to do this modification.
If you use a XBOSOZ with singleended output, then you woun´t benefit from the X, and all you gets is the usual Negative Feed Back, I have not tried this but my gess is that it woun´t sound the best.
__________________
Henrik
  Reply With Quote
Old 26th May 2003, 02:29 PM   #3
moe29 is offline moe29  United States
diyAudio Member
 
moe29's Avatar
 
Join Date: Dec 2002
Location: Florida
Send a message via AIM to moe29 Send a message via Yahoo to moe29
Kilentra - go ahead and build the BZLS i'm using it as
single ended IN to single ended OUT and it sounds fine.
It also sound great single ended IN to balanced OUT when
i'm running my SOZ amps.

Henrik, is the X effective if you are using the BZLS as an
unbalanced to balanced converter? I never really thought of
that... there just seems to be so few truly balanced sources
to run the preamp fully balanced.

(is there a truly balanced CD player for under $1,000 US?)


moe29
  Reply With Quote
Old 26th May 2003, 07:46 PM   #4
Henrik is offline Henrik  Denmark
diyAudio Member
 
Join Date: Feb 2002
Location: Copenhagen Denmark
moe29

Read this post: http://www.diyaudio.com/forums/showt...5141#post75141

Regards Henrik
__________________
Henrik
  Reply With Quote
Old 26th May 2003, 09:16 PM   #5
moe29 is offline moe29  United States
diyAudio Member
 
moe29's Avatar
 
Join Date: Dec 2002
Location: Florida
Send a message via AIM to moe29 Send a message via Yahoo to moe29
thanks Henrik! - i'd read that before, but reading it again in this
new light helps.

...now if someone could just post a step by step way to wire
my BOSOZ and SOZ to X i'd be happy

even so, i'm really enjoying them as they are.

BZLS = Most Valuable Player of the PASS DIY circuits


moe29
  Reply With Quote
Old 27th May 2003, 12:19 PM   #6
protos is offline protos  Greece
diyAudio Member
 
protos's Avatar
 
Join Date: Mar 2002
Location: Athens+Addis Ababa
Quote:
Originally posted by moe29
(is there a truly balanced CD player for under $1,000 US?)


moe29
You might be able to find the Teac VRDS-25 used for less than that and it sounds really twice as good than single -ended driving the Bosoz in balanced mode.
  Reply With Quote
Old 27th May 2003, 02:35 PM   #7
Taco is offline Taco  Netherlands
diyAudio Member
 
Join Date: Nov 2002
Location: Place in the Netherlands
Quote:
Originally posted by protos


You might be able to find the Teac VRDS-25 used for less than that and it sounds really twice as good than single -ended driving the Bosoz in balanced mode.

But driving the Bosoz in balanced mode will get you a unbalanced output. Or am I missing something?
  Reply With Quote
Old 27th May 2003, 04:46 PM   #8
Variac is offline Variac  United States
diyAudio Editor
 
Variac's Avatar
 
Join Date: Dec 2001
Location: San Francisco, USA
The ADCOM GCD-750 CD Player has balanced circuitry and outputs But it is about $1300 new.
  Reply With Quote
Old 27th May 2003, 05:55 PM   #9
moe29 is offline moe29  United States
diyAudio Member
 
moe29's Avatar
 
Join Date: Dec 2002
Location: Florida
Send a message via AIM to moe29 Send a message via Yahoo to moe29
Variac, i've seen that Adcom player and thought that might be
a nice pickup. I was really almost ready to buy a Sony SCD-1,
because it can play SACD's too. But then i saw where Mr. Pass
said that it sounded better through it's single ended outputs,
because it had to process the signal through extra circuitry to
get a balanced output. So i guess just because a player has
balanced outputs doesn't necessarily mean they are truly bal.

maybe it's not that big a deal. It seems like you get a lot of the
advantage of a balanced output using the BZLS as a converter.
I'll save the money spent on a source for experimenting with more
DIY projects! (like learning to X a BZLS)

---------------------
moe29
  Reply With Quote
Old 27th May 2003, 06:17 PM   #10
Variac is offline Variac  United States
diyAudio Editor
 
Variac's Avatar
 
Join Date: Dec 2001
Location: San Francisco, USA
Yup, I'm going to use the XBOSOZ as a converter for the near future, Maybe if a great, universal format balanced player around $1000 comes out I'll be tempted

I'm pretty sure that the Adcom is truly a balanced circuit, and from a series that includes the preamp using a Nelson Pass circuit, so it seems it would play well with our DIY Pass projects.
  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
The Use of 1:1 Input Transformers in Linestages mach1 Tubes / Valves 2 10th December 2008 12:22 PM
CFB and A2 operation hemgjord Tubes / Valves 2 9th September 2008 10:42 PM
operation below fs zenmasterbrian Subwoofers 60 21st October 2006 11:40 PM
unbalanced/balanced/unbalanced conversion using transformers vladimir Solid State 10 27th February 2003 06:54 PM
Erno Borbley preamp linestages Trax Solid State 2 5th October 2001 02:32 AM


New To Site? Need Help?

All times are GMT. The time now is 10:36 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