output devices on X -X.5 and XA.5 - Page 3 - 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 5th September 2012, 04:36 PM   #21
Zen Mod is offline Zen Mod  Serbia
diyAudio Member
 
Zen Mod's Avatar
 
Join Date: Jan 2003
Location: ancient Batsch , behind Iron Curtain
see how is made SE bias on OP chips - same principle , as Pa pointed few times

UGS - I'm really not allowed to say anything about similarity of DIY versions , comparing to origigi PL ......

regarding regs in XS amps, I can't find any hint about in any XS related writing ..... and I didn't ask Pa that ....... so - take my words with grain of salt ;

anyway - Iq is huge in these amps ....... so I really can't believe in existence of any reg
__________________
my Papa is smarter than your Nelson !
clean thread; Cook Book;PSM LS Cook Book;Baby DiyA ;Mighty ZM's Bloggg;Papatreasure;Papa... by Mighty ZM

Last edited by Zen Mod; 5th September 2012 at 04:39 PM.
  Reply With Quote
Old 5th September 2012, 04:52 PM   #22
diyAudio Member
 
Stefanoo's Avatar
 
Join Date: Apr 2006
Location: italia - ora USA -WI
Quote:
Originally Posted by Zen Mod View Post
see how is made SE bias on OP chips - same principle , as Pa pointed few times

UGS - I'm really not allowed to say anything about similarity of DIY versions , comparing to origigi PL ......

regarding regs in XS amps, I can't find any hint about in any XS related writing ..... and I didn't ask Pa that ....... so - take my words with grain of salt ;

anyway - Iq is huge in these amps ....... so I really can't believe in existence of any reg
Understandable as far as Pass's production UGSs.
Did NP point out a specific OP amp to look at as a model?

The XSs look like monster and I wonder why then the PSU has big heatsinks....these amps are a masterwork design!!!
__________________
Stefano
  Reply With Quote
Old 5th September 2012, 04:53 PM   #23
Zen Mod is offline Zen Mod  Serbia
diyAudio Member
 
Zen Mod's Avatar
 
Join Date: Jan 2003
Location: ancient Batsch , behind Iron Curtain
Quote:
Originally Posted by Stefanoo View Post
....
Did NP point out a specific OP amp to look at as a model?
....!
nope; irrelevant
__________________
my Papa is smarter than your Nelson !
clean thread; Cook Book;PSM LS Cook Book;Baby DiyA ;Mighty ZM's Bloggg;Papatreasure;Papa... by Mighty ZM
  Reply With Quote
Old 5th September 2012, 05:52 PM   #24
diyAudio Member
 
Stefanoo's Avatar
 
Join Date: Apr 2006
Location: italia - ora USA -WI
Quote:
Originally Posted by Zen Mod View Post
nope; irrelevant

ahahah...how would that be irrelevant? There are zillions of OPAMPS out there.....
Maybe it would be quicker to open up a X250.5 or a X350.5 and see how it works.
I think I will do that.....too many useless secrets around here in this forums....that are just behind 10 screws...under the hood.... and available to almost anybody....

__________________
Stefano
  Reply With Quote
Old 5th September 2012, 05:57 PM   #25
Zen Mod is offline Zen Mod  Serbia
diyAudio Member
 
Zen Mod's Avatar
 
Join Date: Jan 2003
Location: ancient Batsch , behind Iron Curtain
well , I know how to implement SE bias at OP output and I'm telling you that type of OP is not having anything with that , regarding principle itself.

in short - just put either resistor or CCS , from stage output to neg PSU leg

I'm lazy to look does X*.5 are having Se BIAS , OR IS THAT SOLELY XA*.5 virtue

sorry , caps lock
__________________
my Papa is smarter than your Nelson !
clean thread; Cook Book;PSM LS Cook Book;Baby DiyA ;Mighty ZM's Bloggg;Papatreasure;Papa... by Mighty ZM
  Reply With Quote
Old 5th September 2012, 06:06 PM   #26
diyAudio Member
 
Stefanoo's Avatar
 
Join Date: Apr 2006
Location: italia - ora USA -WI
no don't worry for the caps lock...
Anyway looking at pictures on the net of the X250 and X250.5 looks like they have same number of output devices.

They really look identical, at least from the pictures, for the exception of the UGS which looks like it is using instead of single lower qualuity input devices, uses the SJ108/SK389, which should make up for the sonical difference.
Last I checked my UGS module doesn't even use two devices from the same family...I can't say more as it is a propreitary thing ahahahahaha
__________________
Stefano

Last edited by Stefanoo; 5th September 2012 at 06:11 PM.
  Reply With Quote
Old 5th September 2012, 06:09 PM   #27
diyAudio Member
 
Stefanoo's Avatar
 
Join Date: Apr 2006
Location: italia - ora USA -WI
Quote:
Originally Posted by Zen Mod View Post
well , I know how to implement SE bias at OP output and I'm telling you that type of OP is not having anything with that , regarding principle itself.

in short - just put either resistor or CCS , from stage output to neg PSU leg

I'm lazy to look does X*.5 are having Se BIAS , OR IS THAT SOLELY XA*.5 virtue

sorry , caps lock
I would think that the SE bias would be solely on the XA which probably has a single end output stahe Aleph's style with the combined front end of the X.5...just my two cents.
Like I said I need to open them up and see how they work
__________________
Stefano
  Reply With Quote
Old 5th September 2012, 06:29 PM   #28
Zen Mod is offline Zen Mod  Serbia
diyAudio Member
 
Zen Mod's Avatar
 
Join Date: Jan 2003
Location: ancient Batsch , behind Iron Curtain
Quote:
Originally Posted by Stefanoo View Post
I would think that the SE bias would be solely on the XA which probably has a single end output stahe Aleph's style with the combined front end of the X.5...just my two cents.
Like I said I need to open them up and see how they work
Quote:
Originally Posted by Zen Mod View Post
X250 - older generation UGS based FE , follower style OS with mosfet bias gene , 4 mosfets in OS quadrant,no SE bias , 2x38-ish Vdc PSU

XA200.5 - newer UGS based FE , follower style OS with shunt reg bias gene,7 (or 8) mosfets in OS quadrant,SE bias , 2x34-ish Vdc PSU


stefanoo - what I wrote above are facts , not guess
__________________
my Papa is smarter than your Nelson !
clean thread; Cook Book;PSM LS Cook Book;Baby DiyA ;Mighty ZM's Bloggg;Papatreasure;Papa... by Mighty ZM
  Reply With Quote
Old 5th September 2012, 06:43 PM   #29
diyAudio Member
 
Stefanoo's Avatar
 
Join Date: Apr 2006
Location: italia - ora USA -WI
Quote:
Originally Posted by Zen Mod View Post
I'm lazy to look does X*.5 are having Se BIAS , OR IS THAT SOLELY XA*.5 virtue

sorry , caps lock
I thought with the statement above you weren't sure.
for the number of MOSFETS I have just checked pictures of the inside on the web, counted the number of output device and concluded they are the same number.
Maybe there are hidden devices don't know, but it's unlikely.

Have you had a chance open both of them?
I don't mean to disregard your fact by any mean and I appreciated your effort in answering my questions
__________________
Stefano
  Reply With Quote
Old 5th September 2012, 06:52 PM   #30
diyAudio Member
 
Stefanoo's Avatar
 
Join Date: Apr 2006
Location: italia - ora USA -WI
Quote:
Originally Posted by Zen Mod View Post

in short - just put either resistor or CCS , from stage output to neg PSU leg


sorry , caps lock
Thanks, This was a rather short but clear explanation.
__________________
Stefano
  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
Output Devices ! cloud Pass Labs 11 10th November 2008 11:37 PM
Xa-30, Xa-60 ? jrsun Pass Labs 1 13th February 2005 10:55 PM
Output devices? Mr Evil Class D 42 12th January 2005 02:18 PM
Little brother of the XA-200 available? (XA-150) MEnsing Pass Labs 17 6th November 2002 05:37 PM


New To Site? Need Help?

All times are GMT. The time now is 02:48 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