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 14th August 2011, 01:39 PM   #191
diyAudio Member
 
Joachim Gerhard's Avatar
 
Join Date: Mar 2009
Nico, could you please post the schematic that you are using right now ? That is the version i like most by intuition.
  Reply With Quote
Old 14th August 2011, 01:56 PM   #192
Salas is online now Salas  Greece
diyAudio Chief Moderator
 
Salas's Avatar
 
Join Date: Oct 2002
Location: Athens-Greece
Also some info on the bias current used, test rails potential, and the power it achieved for 0.1% THD on 8 & 4 Ohm, will be welcome.
  Reply With Quote
Old 14th August 2011, 02:32 PM   #193
Bigun is offline Bigun  Canada
diyAudio Member
 
Bigun's Avatar
 
Join Date: Jan 2009
Blog Entries: 2
Quote:
Originally Posted by Lazy Cat View Post
Offset trimmer was missing, now output DC OK.
I like it in BJT-only form, this has every chance to be a popular circuit.

I find the way you have drawn the schematic adds to the interest for me, not sure I can explain, but it looks nice
__________________
"The test of the machine is the satisfaction it gives you. There isn't any other test. If the machine produces tranquility it's right. If it disturbs you it's wrong until either the machine or your mind is changed." Robert M Pirsig.
  Reply With Quote
Old 14th August 2011, 03:35 PM   #194
diyAudio Member
 
Lazy Cat's Avatar
 
Join Date: Sep 2007
It will be even more popular with values given.

So now in this configuration we have 4,3mA input BJT's collector current, 15,9mA driver's current and an output BJT's quiescent current adjustable from 0 to 1,8A.
Attached Images
File Type: jpg SSA TT.jpg (295.8 KB, 1533 views)
  Reply With Quote
Old 14th August 2011, 04:28 PM   #195
diyAudio Member
 
Lazy Cat's Avatar
 
Join Date: Sep 2007
These values are of course discussable, cause now I see that the second stage (driver) voltage gain should be significantly higher, so substantial reduction of 22 ohm emitter resistance must be done. Recalculation in progress ...
  Reply With Quote
Old 14th August 2011, 04:39 PM   #196
wahab is offline wahab  Algeria
diyAudio Member
 
Join Date: Nov 2009
Location: algeria/france
Quote:
Originally Posted by Lazy Cat View Post
These values are of course discussable, cause now I see that the second stage (driver) voltage gain should be significantly higher, so substantial reduction of 22 ohm emitter resistance must be done. Recalculation in progress ...
A good option would be to simply implement a double EF
as output stage , reducing THD efficently , as displayed
in the following graph.

IQ is about 0.42A in both cases.
Attached Images
File Type: gif LAZYCAT THD1.gif (38.6 KB, 1381 views)
File Type: gif LAZYCAT MODDED.gif (11.6 KB, 1331 views)
  Reply With Quote
Old 14th August 2011, 04:57 PM   #197
diyAudio Member
 
Lazy Cat's Avatar
 
Join Date: Sep 2007
Quote:
Originally Posted by wahab View Post
A good option would be to simply implement a double EF
as output stage , reducing THD efficently , as displayed
in the following graph.

IQ is about 0.42A in both cases.
I know but than we are a little out of the concept.

Please recheck THD with these new values.
Attached Images
File Type: jpg SSA TT.jpg (305.7 KB, 1541 views)
  Reply With Quote
Old 14th August 2011, 05:08 PM   #198
wahab is offline wahab  Algeria
diyAudio Member
 
Join Date: Nov 2009
Location: algeria/france
Quote:
Originally Posted by Lazy Cat View Post
I know but than we are a little out of the concept.

Please recheck THD with these new values.
This is better but still more than 20db higher THD
than with a double EF final stage.
The VAS is really too much loaded and this ruin this circuit
capabilities wich are quite good given the schematic simplicity.

Good work , Lazycat , anyway...
  Reply With Quote
Old 14th August 2011, 05:16 PM   #199
diyAudio Member
 
Lazy Cat's Avatar
 
Join Date: Sep 2007
It looks in this concept with 8 transistors, lateral MOSFET output's would give the best THD figures, loading the VAS less than other versions.

MOSFET driver is another option, maybe ... the best solution of this simple concept lies in the right driver/output configuration, as we have already discussed here.

Last edited by Lazy Cat; 14th August 2011 at 05:21 PM.
  Reply With Quote
Old 14th August 2011, 05:17 PM   #200
diyAudio Member
 
Joachim Gerhard's Avatar
 
Join Date: Mar 2009
How about a BJT - Lateral Mos Szikley compound ? I really would prefer that the mosfets drive the speaker from the drain but i am not a power amplifier specialist.
  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
Symetrical schematics are alike plague in Brazil, do you like them? destroyer X Solid State 151 1st July 2010 02:09 PM
Symetrical out low Zout karsten21 Tubes / Valves 5 1st February 2010 10:19 PM
going balanced/symetrical - what benefits? weissi Solid State 15 20th October 2007 08:06 AM
Symetrical field, is this? Raka Multi-Way 6 14th September 2003 01:21 PM
Non-symetrical SMPS output cm961 Parts 4 21st August 2003 10:27 PM


New To Site? Need Help?

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