Turning a dead Class-A into a GC - diyAudio
Go Back   Home > Forums > Amplifiers > Chip Amps

Chip Amps Amplifiers based on integrated circuits

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 28th March 2004, 04:55 PM   #1
diyAudio Member
 
Join Date: Dec 2002
Location: sarasota, fl
Default Turning a dead Class-A into a GC

Here is the find: A 1/2 working SAE A-205 amp at a garage sale for $10. The bad news: The non-working channel is smoked, and will not be a fun repair. I am a GC virgin and want to know how much I would have to put into this to turn it into a nice GC (100wpc) amp.

Here is the pic of what I got
Click the image to open in full size.
  Reply With Quote
Old 28th March 2004, 05:04 PM   #2
diyAudio Member
 
Bill Fitzpatrick's Avatar
 
Join Date: Jun 2001
Location: Eugene, OR
What you got is a 412K photo. I lost interest while it was loading.
  Reply With Quote
Old 28th March 2004, 05:10 PM   #3
diyAudio Member
 
Join Date: Dec 2002
Location: sarasota, fl
Quote:
Originally posted by Bill Fitzpatrick
What you got is a 412K photo. I lost interest while it was loading.

I guess what you don't have is broadband
  Reply With Quote
Old 28th March 2004, 05:22 PM   #4
diyAudio Member
 
bigparsnip's Avatar
 
Join Date: Apr 2003
Location: Cambridge
Try doing a search for bridge clone, as you have more than enough heatsinking there to get you going and plenty of room to fit in the transformer and other bits and pieces.

This thread may be a good place to start:

Bridgeclone

And national have an aplication note abou this topic which is probably worth you reading too.

http://www.national.com/appinfo/audi...ation_Note.pdf

And

http://www.national.com/an/AN/AN-1192.pdf
  Reply With Quote
Old 28th March 2004, 05:40 PM   #5
diyAudio Member
 
Bill Fitzpatrick's Avatar
 
Join Date: Jun 2001
Location: Eugene, OR
Quote:
Originally posted by mikejz84



I guess what you don't have is broadband
Having bloated photos partly defeats the purpose of broadband. Your pic resizes nicely to 57K and still makes the point.
  Reply With Quote
Old 28th March 2004, 05:45 PM   #6
sreten is offline sreten  United Kingdom
diyAudio Member
 
Join Date: Nov 2003
Location: Brighton UK
You'll need to bridge to get decent output.

Personally I'd fix the (far superior) class A amplifier.

sreten.
  Reply With Quote
Old 28th March 2004, 06:47 PM   #7
Nuuk is offline Nuuk  United Kingdom
diyAudio Member
 
Nuuk's Avatar
 
Join Date: Feb 2003
Location: Somerset, SW England
I'm not sure if I would recommend a bridged Gainclone as a first project. Why do you want/need 100 wpc?

Try a plain vanilla Gainclone first and to get some idea of how to achieve that, take a look at a similar project of mine.
__________________
The truth need not be veiled, for it veils itself from the eyes of the ignorant.
  Reply With Quote
Old 28th March 2004, 06:49 PM   #8
diyAudio Member
 
Join Date: Dec 2002
Location: sarasota, fl
I would use the amp to drive my NHT VT-2s, they are power ******. I Bi-amp them right now 75watts for the highs and 100watts for the lows, and still that is just enought.
  Reply With Quote
Old 28th March 2004, 06:52 PM   #9
Nuuk is offline Nuuk  United Kingdom
diyAudio Member
 
Nuuk's Avatar
 
Join Date: Feb 2003
Location: Somerset, SW England
Quote:
I would use the amp to drive my NHT VT-2s, they are power ******. I Bi-amp them right now 75watts for the highs and 100watts for the lows, and still that is just enought.
"******" is the right word Get rid of them and build something efficient.
__________________
The truth need not be veiled, for it veils itself from the eyes of the ignorant.
  Reply With Quote
Old 28th March 2004, 08:27 PM   #10
paulb is offline paulb  Canada
diyAudio Member
 
Join Date: Jun 2001
Location: Calgary
Other than bigparsnip, you folks have been much less than helpful. I say go for it. I'm currently thinking about changing an old Class AB to a Class A. Why not?
Nuuk's suggestion is a good one, if you haven't built much before. Maybe try a bare-bones, open-frame gainclone first, you could even power it from the SAE amp power supply. Then build the real one and go nuts.
  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
JBL PB12 subwoofer, Class D amp, dead. pat allen Class D 344 26th January 2014 06:39 PM
dead time, and class D distortion zenmasterbrian Class D 90 22nd January 2007 12:47 PM


New To Site? Need Help?

All times are GMT. The time now is 12:27 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