KA30se "KRYPTON" SE class A amplifier - diyAudio
Go Back   Home > Forums > Amplifiers > Pass Labs

Pass Labs This forum is dedicated to Pass Labs discussion.

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 26th September 2007, 06:23 PM   #1
diyAudio Member
 
bogdan_borko's Avatar
 
Join Date: Nov 2005
Location: serbia, zajecar
Default KA30se "KRYPTON" SE class A amplifier

This is the finall version of the amplifier I`ve been working on lately. It is a class A amplifier single ended with impemented "aleph ccs".

30W on 4Ohm load
Open loop distortion @ 1W/4Ohm = 0.03
Open loop bandwidth 48KHz (-3dB)
CL distortion @ 95% power = 0.08%
CL bandwidth 480KHz
Attached Images
File Type: gif ka30se.gif (16.3 KB, 2192 views)
  Reply With Quote
Old 26th September 2007, 06:25 PM   #2
diyAudio Member
 
bogdan_borko's Avatar
 
Join Date: Nov 2005
Location: serbia, zajecar
ps regulator
Attached Images
File Type: gif ps-regulator-.gif (7.2 KB, 1778 views)
  Reply With Quote
Old 26th September 2007, 06:31 PM   #3
diyAudio Member
 
bogdan_borko's Avatar
 
Join Date: Nov 2005
Location: serbia, zajecar
pcb
Attached Images
File Type: jpg pcb.jpg (64.2 KB, 1667 views)
  Reply With Quote
Old 26th September 2007, 06:34 PM   #4
diyAudio Member
 
bogdan_borko's Avatar
 
Join Date: Nov 2005
Location: serbia, zajecar
What I`d like to ask is it comensated right and is there any specific type of compensation i should try?

BTW the sound is VERY good and precise nothing like the classic SE amplifiers..

Thanks in advance, Borko.
  Reply With Quote
Old 26th September 2007, 09:32 PM   #5
The one and only
 
Nelson Pass's Avatar
 
Join Date: Mar 2001
Very nice looking circuit. I would expect that simply
trimming C9 and the Gate/Base stopper values
plus potentially capacitance around Q3 (CE or CB)
would cover the whole subject of compensation.

Easiest to adjust against a square wave into the loads
of interest.

  Reply With Quote
Old 27th September 2007, 09:54 PM   #6
diyAudio Member
 
bogdan_borko's Avatar
 
Join Date: Nov 2005
Location: serbia, zajecar
Thanks mr.Pass I`ll try it.

BTW you , mr.John Curl any many others are proposing low feedback design...

I tried to remove (C10/C11) in order to decrese OLG and descovered that amplifier sounded worse. Hi OLG mode sounded more opened with more details!

What`s the catch??
  Reply With Quote
Old 28th September 2007, 05:33 PM   #7
diyAudio Member
 
bogdan_borko's Avatar
 
Join Date: Nov 2005
Location: serbia, zajecar
I admit that "What`s the catch??" is a bit silly formulated question, but the listening tests confirmed that the Hi-OLG mode sounded better. I`m bit confused now..
  Reply With Quote
Old 28th September 2007, 07:11 PM   #8
The one and only
 
Nelson Pass's Avatar
 
Join Date: Mar 2001
Quote:
Originally posted by bogdan_borko
I tried to remove (C10/C11) in order to decrese OLG and descovered that amplifier sounded worse. Hi OLG mode sounded more opened with more details!
Without knowing values of components, it's difficult to judge.

  Reply With Quote
Old 28th September 2007, 08:27 PM   #9
diyAudio Member
 
bogdan_borko's Avatar
 
Join Date: Nov 2005
Location: serbia, zajecar
No problem...
Attached Images
File Type: gif ka30se-full.gif (18.6 KB, 1548 views)
  Reply With Quote
Old 28th September 2007, 09:14 PM   #10
diyAudio Member
 
bogdan_borko's Avatar
 
Join Date: Nov 2005
Location: serbia, zajecar
Some data:
Q1 current 11.6mA
Q2 current 13mA
Total bias of output stage = 2A (1A per device)


1. I also tried 2SJ103BL low gm jfet for Q1 ( the only I could find here) and the sound was lot worse, kind a "muddy".

2. I descovered that lowering R6/R7 for higher Q1 gm sound better.
  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
What makes an amplifier "bright", "warm", or "neutral"? JohnS Solid State 51 13th December 2009 07:42 PM
KA30se "KRYPTON" SE class A amplifier bogdan_borko Solid State 10 30th September 2007 08:57 PM
Schematic for Zetex "ZXCD500MOEVAL" - Class D Eval Board ? CAindoAUDIO Class D 1 16th November 2006 04:44 PM


New To Site? Need Help?

All times are GMT. The time now is 01:11 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