building amps

[homertooties]

Hi all
has anyone built this amp i did very cheap to buy parts,what do you think can it be improved on

 

[homertooties]

here is another pic

another pic

 

[Cal Weldon]

I merged your threads.

 

[edl]

here you are

 

[AndrewT]

Hi,
the output stage bias depends on the diodes for voltage control.

If you keep the heatsink cold, then the bias could remain safe. But if the sink is allowed to heat up then the bias will increase and you could get thermal runaway in the output stage.

You have two components helping prevent this. Your 0r51 emitter resistors are very large and secondly the output has a very low quiescent bias due to only two diodes being used. You may be OK.

However a small modification will help. Move the two diodes to lie (glued) in contact with the heatsink. As the sink temperature rises the diode voltage falls and corrects the bias current in the outputs.

 

[sousmielie]

Hi,

I have built this amp a couple of years ago. It's very simple and easy to build and get working. I have built it with more output transistors, and changed the bias. I'll have a look at all the mods I have made and let you know.

This is a nice amp to begin with and is very cheap!!! Sound quality isn't too bad, mine has nice bass.

Cheers,
Werner

 

[Leolabs]

I remembered someone did build it without PCB.