UAS - Universal Amplification Stage - 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 13th August 2008, 09:26 AM   #1
Stee is offline Stee  Italy
diyAudio Member
 
Stee's Avatar
 
Join Date: Jul 2005
Location: milan
Lightbulb UAS - Universal Amplification Stage

Hello to All

I will present my recent idea - the UAS

This amplifier has the ability to govern themselves alone
thanks to local feedback on output resistors

it's esoteric because ultra simple
it's complementary
can build in chain with different power

need matching devices
do not need adjustment
have gain in voltage and in current

can use LED for biasing
between pre and final stages better put a potentiometer
its natural evolution provides the drive with mosfets

do you think it's intresting?
never tested
Attached Images
File Type: gif uas.gif (6.2 KB, 1585 views)
__________________
Please download my best audio idea https://www.facebook.com/DiyAudioHiEnd
  Reply With Quote
Old 13th August 2008, 09:33 AM   #2
diyAudio Member
 
jan.didden's Avatar
 
Join Date: May 2002
Location: Great City of Turnhout, Belgium
Blog Entries: 7
Is this supposed to be used as a power buffer because of the gain of one? As the output stage of a power amp?

One potential problem would be the output DC offset.

Jan Didden
__________________
If you don't change your beliefs, your life will be like this forever. Is that good news? - W. S. Maugham
Check out Linear Audio!
  Reply With Quote
Old 13th August 2008, 11:06 AM   #3
Stee is offline Stee  Italy
diyAudio Member
 
Stee's Avatar
 
Join Date: Jul 2005
Location: milan
Default Better this?

Regards
Attached Images
File Type: gif uas2.gif (7.3 KB, 1320 views)
__________________
Please download my best audio idea https://www.facebook.com/DiyAudioHiEnd
  Reply With Quote
Old 13th August 2008, 12:54 PM   #4
Stee is offline Stee  Italy
diyAudio Member
 
Stee's Avatar
 
Join Date: Jul 2005
Location: milan
Default optimization

now you can see
at the same time there is :

VOLTAGE GAIN

DC offset control
Thermal drift biasing
Negative feedback subtraction
Attached Images
File Type: gif uas3.gif (7.7 KB, 1255 views)
__________________
Please download my best audio idea https://www.facebook.com/DiyAudioHiEnd
  Reply With Quote
Old 13th August 2008, 01:01 PM   #5
diyAudio Member
 
Join Date: Aug 2008
It will have very high THD because of the full class B bias setting.
And there is NO negative feedback.

regards,
Guthorst
  Reply With Quote
Old 13th August 2008, 01:05 PM   #6
Stee is offline Stee  Italy
diyAudio Member
 
Stee's Avatar
 
Join Date: Jul 2005
Location: milan
Default Guthorst see now

I have edited with double input diode

please write on schematic your modification
Attached Images
File Type: gif uas3.gif (8.0 KB, 1196 views)
__________________
Please download my best audio idea https://www.facebook.com/DiyAudioHiEnd
  Reply With Quote
Old 13th August 2008, 01:07 PM   #7
lineup is offline lineup  Sweden
diyAudio Member
 
lineup's Avatar
 
Join Date: Dec 2005
Location: the north
you can add one film capacitor
across those 2 input diodes
... from base to base of input transistors

will act as a sort of BOOTSTRAP
something like 1 uF would maybe be suitable

otherwise I think your amplifier is a very nice idea
more creative and interesting
than most I can discover at this board from other posters
__________________
lineup
  Reply With Quote
Old 13th August 2008, 03:24 PM   #8
diyAudio Member
 
jan.didden's Avatar
 
Join Date: May 2002
Location: Great City of Turnhout, Belgium
Blog Entries: 7
Quote:
Originally posted by Guthorst
It will have very high THD because of the full class B bias setting.
And there is NO negative feedback.

regards,
Guthorst

... but there is a LOT of nfb. And the biasing is probably class AB. But that's easy to set with some resistor values.

My question is more, what's 'universal' about this?

Jan Didden
__________________
If you don't change your beliefs, your life will be like this forever. Is that good news? - W. S. Maugham
Check out Linear Audio!
  Reply With Quote
Old 13th August 2008, 08:49 PM   #9
Stee is offline Stee  Italy
diyAudio Member
 
Stee's Avatar
 
Join Date: Jul 2005
Location: milan
Default Hi Janneman

I called Universal
because as for OPA
is a model that you can repeat the same at every level of power

does not require settings - so it is configured with a standard, perhaps an integrated

also evades the tradition that wants to always be the mirror of current in input
bias control in VAS
and the output stage only in current gain

also has the ambition to become globally esoteric
because extremely simple (perhaps sounds good)
you may have to hold a conference to AES in New York...

the only new idea (I think)
is to use a shunt to monitor the current on each branch
in very short rings

I hope also become Universal with your contribution
maybe a good idea use FET/Mosfet in input...

Regards and Thanks

Hi lineup
thanks a lot for your support
this 1uF film capacitor from base to base it's for RF filter?

Attached Images
File Type: gif uas3.gif (7.9 KB, 1107 views)
__________________
Please download my best audio idea https://www.facebook.com/DiyAudioHiEnd
  Reply With Quote
Old 13th August 2008, 09:22 PM   #10
Eva is offline Eva  Spain
diyAudio Member
 
Eva's Avatar
 
Join Date: Oct 2003
Location: Near the sea
Send a message via MSN to Eva
This circuit has been in use for the past 30 years. There is nothing innovative in it. Its main drawback is cross-conduction at high frequencies.
__________________
I use to feel like the small child in The Emperor's New Clothes tale
  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
GAS - Global Amplification Stage Stee Solid State 17 19th August 2008 03:58 AM
Multi-stage amplification sam9 Solid State 2 5th August 2007 04:49 PM
amplification? xstephanx Full Range 29 4th June 2006 05:58 PM
Amplification Howard Subwoofers 5 25th December 2004 07:03 AM
power amplifier with one-stage voltage amplification alex0 Solid State 5 7th February 2004 12:02 PM


New To Site? Need Help?

All times are GMT. The time now is 04:46 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