Common base VAS - diyAudio
Go Back   Home > Forums > Amplifiers > Solid State

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 25th June 2011, 09:00 PM   #1
Stee is offline Stee  Italy
diyAudio Member
 
Stee's Avatar
 
Join Date: Jul 2005
Location: milan
Default Common base VAS

this amplifier is a modification of a-680 diyGene.com
is an inverting amplifier
so don't need current mirror
I have connected jfet source on GROUND as tube's design
that works very fine

DIYGene - Electronics DIY, Hi Fi , amplifier
Attached Images
File Type: jpg A680GND.jpg (159.6 KB, 199 views)
__________________
Please download my best audio idea https://www.facebook.com/DiyAudioHiEnd

Last edited by Stee; 25th June 2011 at 09:05 PM.
  Reply With Quote
Old 26th June 2011, 01:22 AM   #2
CBS240 is offline CBS240  United States
diyAudio Member
 
CBS240's Avatar
 
Join Date: Aug 2005
Location: K-town
If you take away the summing node and make it gnd, the diff amp is no longer a diff amp. You have two common source amplifiers, with different transfer characteristics and distortion spectrum. If it works it works, but it is nothing particularly special. Symmetrical folded cascode VAS. Is there a different perception of the sound after swapping the input stage?
__________________
All the trouble I've ever been in started out as fun......

Last edited by CBS240; 26th June 2011 at 01:25 AM.
  Reply With Quote
Old 26th June 2011, 08:17 AM   #3
Stee is offline Stee  Italy
diyAudio Member
 
Stee's Avatar
 
Join Date: Jul 2005
Location: milan
Default yes of course

never listening a better amplifier
probably because don't have differential stage
or because have ground reference like triode (not so easy to found)
also because I have simulate internal balanced power supply
with two transformers in input
one of these do an inverting phase
and the same again in output polarity

in other words

to get the advantage of balanced sound
without risk of adding errors
just take a power transformer as input converter

you can simulate the natural balance of power supply like true balanced AMP
inverting a channel input (secondary polarity) and output (loudspeaker)
Attached Images
File Type: png trasformatore convertitore2.PNG (75.3 KB, 130 views)
File Type: jpg A680GND2.JPG (199.0 KB, 121 views)
__________________
Please download my best audio idea https://www.facebook.com/DiyAudioHiEnd

Last edited by Stee; 26th June 2011 at 08:44 AM.
  Reply With Quote
Old 26th June 2011, 02:43 PM   #4
Stee is offline Stee  Italy
diyAudio Member
 
Stee's Avatar
 
Join Date: Jul 2005
Location: milan
Default see a ZOOM

of input and VAS stages
Attached Images
File Type: png HALF CHANNEL IN-VAS.PNG (79.2 KB, 101 views)
__________________
Please download my best audio idea https://www.facebook.com/DiyAudioHiEnd
  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
AD844 as a common base stage in the I/V converter Pedja Digital Source 42 25th March 2013 07:56 AM


New To Site? Need Help?

All times are GMT. The time now is 10:06 AM.


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