Anyone built this power Diamond Buffer amp ? - 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 16th May 2011, 05:14 PM   #1
diyAudio Member
 
Shoog's Avatar
 
Join Date: Aug 2002
Location: Eire
Default Anyone built this power Diamond Buffer amp ?

Hi there all,
I usually do valve stuff but have accumulated some nice Sanken complimentary pairs and the dead guts of a Zen V3. I want to build something which has a fighting chance of comparing with my Class A PP valve amp.
I came across this design when searching and it looks to have the virtues of elegant simplicity and Class A operation. Has anyone built it or anyone care to express an opinion on its potential performance.
Details are a bit scant, and it doesn't even suggest potential power output. I only need about 8Watts of good class A.

Shoog
Attached Images
File Type: png fetbuffer_DIAMOND_CFP.PNG (191.6 KB, 1067 views)
  Reply With Quote
Old 16th May 2011, 06:53 PM   #2
expert in tautology
diyAudio Member
 
bear's Avatar
 
Join Date: Apr 2002
Location: New York State USA
I've built and used the second half without the last pair. Prefered it modified to use a jfet
in and a Mosfet out... but it's a good buffer...

I'd suggest you try the Pass F5 if you want to beat up ur 300B PP amp... of course the specific parts you use for the F5 will change it's sonic appearance rather a lot...

Otoh, why not try something like what you have shown... not sure how the two parts shown got combined, as they seem to be from different sources...

_-_-bear
got combined, but...
__________________
_-_-bear
http://www.bearlabs.com -- Btw, I don't actually know anything, FYI -- [...2SJ74 Toshiba bogus asian parts - beware! ]
  Reply With Quote
Old 16th May 2011, 06:57 PM   #3
diyAudio Member
 
Shoog's Avatar
 
Join Date: Aug 2002
Location: Eire
Have the Sankens so thought this would be a good try out.
I know the F5 is an outstanding amp, but I don't want to splash the cash when I have good components lying around.

I was contemplating replacing the front end with a Valve stage - an octal for a change.

Shoog
  Reply With Quote
Old 17th May 2011, 02:00 PM   #4
juma is offline juma  Germany
diyAudio Member
 
juma's Avatar
 
Join Date: Nov 2005
Location: Berlin
Drawn as it is, the output stage won't work. Stee draws stuff like that all the time...

If you want BJT power buffer that much, you can try this (Push Pull Pure Class A "Hot Follower 99" Amplifier
designed by: Andrea Ciuffoli) - at least, it will work:
Andrea Ciuffoli - Home Page

Last edited by juma; 17th May 2011 at 02:04 PM.
  Reply With Quote
Old 17th May 2011, 03:25 PM   #5
diyAudio Member
 
Shoog's Avatar
 
Join Date: Aug 2002
Location: Eire
So how about Pavels Buffer.
This is a proven design right ?

Though it would seem that a quick look at the outputs datasheet suggests they are an entirely different beast to the Sankens I have.

Shoog
Attached Images
File Type: gif pma1sch.gif (16.4 KB, 929 views)

Last edited by Shoog; 17th May 2011 at 03:35 PM.
  Reply With Quote
Old 17th May 2011, 03:42 PM   #6
lineup is offline lineup  Sweden
diyAudio Member
 
lineup's Avatar
 
Join Date: Dec 2005
Location: the north
PMA Pavel's buffer is much better.
If you want Class A.
You can count on he has fineadjusted as much as possible.
You can trust his circuit.

For other voltages than 27V you should change R11/R12 accordingly.

You should be able to use other OP Transistors.
Some would even fit better.
THe output pair are not critical to that circuit
__________________
lineup

Last edited by lineup; 17th May 2011 at 03:44 PM.
  Reply With Quote
Old 17th May 2011, 03:55 PM   #7
diyAudio Member
 
Shoog's Avatar
 
Join Date: Aug 2002
Location: Eire
Thanks for the input.
My understanding is that this circuit is capable of 35W class A. My valve experience says I need just 8W to be happy. The transformer I have is a beefy 12-0-12V AC so would be running just +/- 16V DC.
It seems this buffer requires about 15mA of drive from the front end.

The Sankens I have to hand are the 2SA1215/2SC2921.

Seems like a runner though - will study this more in about a week when I am not so busy.

Shoog

Last edited by Shoog; 17th May 2011 at 04:07 PM.
  Reply With Quote
Old 17th May 2011, 04:44 PM   #8
lineup is offline lineup  Sweden
diyAudio Member
 
lineup's Avatar
 
Join Date: Dec 2005
Location: the north
I have spice models for 2SC2922/2SA1216. But not 2SC2921/2SA1215
As I told, I do not think there is much problem with what power transistors you use.
More important is to use 2 good drivers of the big transistors.

Here I post my take on +/-16 Volt Diamond Sziklai in Class A.
It shows very low distortion for being with No Feedback.

Input is +/-12 Volt peak, ~ 9 Watt RMS Class A
THD simulates to 0.006%

Output transistors are 2SC5200/2SA1943
Attached Images
File Type: png diamond_sziklai_4b_16v.png (17.1 KB, 851 views)
__________________
lineup
  Reply With Quote
Old 17th May 2011, 05:05 PM   #9
diyAudio Member
 
Shoog's Avatar
 
Join Date: Aug 2002
Location: Eire
Cheers - thanks for that.

Looking good.

Shoog
  Reply With Quote
Old 17th May 2011, 05:45 PM   #10
jaycee is offline jaycee  United Kingdom
diyAudio Member
 
Join Date: Apr 2004
Location: Norwich, UK
I'd probably use a current mirror or constant current source/sinks rather than the bootstraps, but it does work. I use a smaller version (with TO-220 outputs) as a headphone amp.
  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
DC adjustable double-Sziklai Power Diamond Buffer mtlin12 Solid State 23 5th August 2014 02:46 PM
four transistor emitter follower (diamond buffer) as power output stage? capslock Solid State 113 12th August 2013 06:16 PM
6DJ8 Shunt Regulated Push-Pull + Sziklai Diamond Power Buffer without Feedback lineup Solid State 2 8th May 2011 08:02 AM
sziklai-darlington diamond buffer (SDDB) for power output stages mtlin12 Solid State 5 1st April 2005 06:55 AM
Current feedback high speed headphone amp with diamond output buffer peranders Headphone Systems 102 30th January 2004 09:53 PM


New To Site? Need Help?

All times are GMT. The time now is 11:17 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