for headphones - diyAudio
Go Back   Home > Forums > Amplifiers > Pass Labs
Home Forums Rules Articles diyAudio Store Gallery Wiki Blogs Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

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
Thread Tools Search this Thread
Old 7th September 2003, 07:06 AM   #1
Prune is offline Prune  Canada
Account Disabled
Join Date: Mar 2003
Location: Vancouver
Default for headphones

Hey, can this be modified to an X amp???
  Reply With Quote
Old 8th September 2003, 01:39 AM   #2
The one and only
Nelson Pass's Avatar
Join Date: Mar 2001
Anything with a differential pair input stage can be mutated
until it is an X amp. In this case, the mutation is not trivial.

BTW, just becuase a "servo" is not directly in the feedback
loop does not mean that it does not affect the sound.
  Reply With Quote
Old 8th September 2003, 08:44 AM   #3
diyAudio Member
Join Date: Jul 2001
Location: The Netherlands
But Gilmore's amp runs openloop... so it would require some modification of the gain of each stage to alow some global x-feedback .

Or do you would the feedback to stay local? Then the modification would only be around the two input stages ala x-bosoz, wouldn't it?

  Reply With Quote
Old 8th September 2003, 09:29 AM   #4
Prune is offline Prune  Canada
Account Disabled
Join Date: Mar 2003
Location: Vancouver
By openloop do you mean no global feedback? There is global feedback -- in the block diagram under the schematic, showing the bias opamp, the feedback goes into -I through the 10K resistor.
Nelson, he didn't write that the sound is totally unaffected by the servo, just that it's a less significant effect.

Actually I'm more interested in another Gilmore amp that I want to build: this one; could this be easier to mutate into a SUSY design?
(I know I asked this in another post, but there wasn't a complete diagram; also sorry about errors in this one)
  Reply With Quote
Old 14th September 2003, 07:41 PM   #5
jwb is offline jwb  United States
diyAudio Member
jwb's Avatar
Join Date: Mar 2002
Location: San Francisco, USA
Send a message via AIM to jwb
This amp design is very weird. The "Servo" is very much in the feedback loop. Just because it runs at an extremely low frequency, doesn't mean the amp has no feedback. The author somehow feels that modulating the current on the front-end is somehow better than just modulating the negative input, but doesn't provide any evidence regarding that. You could replace the whole servo setup with a pot, adjust it once, and be done with it.
  Reply With Quote


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
ZEN-like headphones amp tortello Pass Labs 205 31st August 2016 08:07 PM
Headphones underwurlde Solid State 3 23rd August 2009 09:09 PM
My new headphones amp Sch3mat1c Solid State 1 25th April 2005 12:13 PM
Which headphones are the best Bull Everything Else 11 8th December 2002 09:17 PM
Headphones JazzFrac Everything Else 2 26th February 2001 05:13 AM

New To Site? Need Help?

All times are GMT. The time now is 01:11 AM.

vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Copyright 1999-2017 diyAudio

Content Relevant URLs by vBSEO 3.3.2