DIY Low Power Class A (or AB) amplifier suggestions - 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 June 2009, 02:25 PM   #1
gareth is offline gareth  Wales
diyAudio Member
 
gareth's Avatar
 
Join Date: Jan 2008
Default DIY Low Power Class A (or AB) amplifier suggestions

Hi guys (and girls),

I would like to build myself my first Class A (maybe AB) amplifier. I have some NPN and PNP BJT's.

I have 22 of each 2N5551 and complimentary 2N5401 BJT's and would like to use these in parallel if possible. The reason for this is that i had read somewhere, sometime ago, that utilising smaller powered devices in parallel helps 'iron-out' any differences between the devices.

At most I am looking for about 30watts per channel in stereo and I have a +-35v centre tapped (secondary side) transformer with a 10.5v output (non centre-tapped). I salvaged this from a Technics Class AA amp and it has PC-OFC windings and a nice copper strip covering the windings to keep stry electromagnetics under 'control', or at least that is whatI thought it was for. The Technics amp it came from was capable of 50w/ch into 4ohm so I think it will be ok.

Thanks in advance
Gareth

P.S I have other complimentary BJT's at my disposal and I would really like to try out these as my first amp, also i would really like to go down the class-a route even though they are not energy efficient. This is my firat amp and i am very anxious and excited at the same time. Thanks again
  Reply With Quote
Old 16th June 2009, 02:39 PM   #2
diyAudio Member
 
destroyer X's Avatar
 
Join Date: Feb 2004
Location: Recife - Brasil Northeast
Default Base to emitter capacitances may be a problem


As i have never tried....do not know the result....will be watching your results.

Carlos
__________________
DxS, the best from the best...the cream from the cream, the best wide world ever made audio amplifier.
  Reply With Quote
Old 16th June 2009, 02:46 PM   #3
wg_ski is offline wg_ski  United States
diyAudio Member
 
Join Date: Oct 2007
Couple of things.... Class A at that power (voltage) level will overload the transformer. Unless you do some sort of advanced sliding bias like the original amp did. I doubt that trafo would be up to the task of a hotter than blazes Pass type amp. High-bias class AB maybe. But forget about paralleling a bunch of TO-92 transistors to get higher power. You would need too many of them and it's more trouble than it's worth when you consider layout and heat sinking. Paralleled TO-126 or TO-220 pairs are more practical, because you can bolt them all down to a common heat sink easily.
  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
Suggestions needed for improving Rogers Cadet II PP power amplifier Sanjiv Sahgal Tubes / Valves 10 23rd May 2012 09:26 AM
High Power Class G amplifier digitoxin Solid State 29 27th October 2009 09:56 AM
Class A diy power amplifier jmar Solid State 1 18th January 2004 06:10 PM
:: class a symetric power amplifier :: dhengkoel Solid State 36 22nd August 2003 03:51 AM
class a power amplifier janey Solid State 4 30th August 2001 10:48 PM


New To Site? Need Help?

All times are GMT. The time now is 11:52 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