Go Back   Home > Forums > Amplifiers > Solid State
Home Forums Rules Articles Store Gallery Blogs Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Solid State Talk all about solid state amplification.

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 30th March 2007, 03:19 PM   #1
roender is offline roender  Romania
diyAudio Member
 
roender's Avatar
 
Join Date: Sep 2006
Default Another feedback compensation method

Hello all,

This is my new test poweramp which have differential VAS, compensated with shunt capacitor from output to ground.
The loop gain is 86dB and phase margin 36dB.
In the searching of a solution to decrease VAS capacitive load, I came to this schematic which have the same loop gain but more phase margin (49dB)
What is your opinion about this compensation type ?

Unmodified amp
Attached Images
File Type: jpg powersymasymv2.jpg (98.3 KB, 374 views)
  Reply With Quote
Old 30th March 2007, 03:21 PM   #2
roender is offline roender  Romania
diyAudio Member
 
roender's Avatar
 
Join Date: Sep 2006
The new compensation methode
Attached Images
File Type: jpg powersymasymv3.jpg (97.4 KB, 375 views)
  Reply With Quote
Old 30th March 2007, 06:26 PM   #3
AndrewT is offline AndrewT  Scotland
diyAudio Member
 
Join Date: Jul 2004
Location: Scottish Borders
Hi,
that 150pF from VAS to inverting input is quite conventional.
used by many British designers (JLH, Crimson, Sugden that I know about) for reputedly improved sound quality.
The phase of your connection seems reversed from the norm.

Can you eliminate C8 & C9 completely and use 150pF//(R+C) to stabilise and tune the phase margin?
__________________
regards Andrew T.
  Reply With Quote

Reply


Hide this!Advertise here!

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
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
TDA7250 feedback compensation question sendler Solid State 4 7th January 2009 08:34 PM
Strange feedback method hotbottle Tubes / Valves 4 12th April 2008 10:38 PM
New capacitive motional feedback method Nuutti Multi-Way 31 14th March 2006 03:04 AM
Unnamed feedback method explored. Mr Evil Solid State 30 23rd November 2004 04:03 PM


New To Site? Need Help?

All times are GMT. The time now is 09:10 AM.

Page generated in 0.05839 seconds (75.18% PHP - 24.82% MySQL) with 11 queries

Copyright ©1999-2012 diyAudio