50-100watt amplifier schematics wanted

[Jean]

Hello,

I am looking for a proven transistor based 50-100 watt solid state amplifier (class a/b) schematics. Looking for a proven design that won't break a bank but will sound good. I am going to be using it with my diy 2way speaker (88db, ss9500 top end with vifa pl18wo mid).

I searched on google and this forum but found only Class A designs, but would like to find something more efficient because finding large heatsinks and large transformer is going to be a hassle.

tia

Jean

[TheDude]

Here's a few links I have found...

http://www.mhennessy.f9.co.uk/

http://www.neilmcbride.co.uk/ <- the one I'm saving up for (look at 'Naim style amps')

http://steve.sky.net.ua/a_index.htm <- loads of stuff

http://users.ece.gatech.edu/~mleach/lowtim/

http://sound.westhost.com/index.html <- quite a lot as well

Hope it helps.

- Stu -

[AKSA]

Hey,

What about the AKSA?

Try www.printedelectronics.com

I should mention I have a vested interest ; I am the designer, and this is a kitset, available as either a 55W or a 100W, complete with heatsinks, but not transformers or case.

Cheers,

Hugh

[Jean]

Hello Hugh,

Your AKSA kit looks very tempting, with complete finished circuit boards and even supplied heatsinks. I wasn't exactly looking for a complete ready to go kit like yours, but it does look interesting I might just get that unless I find something else more "challenging" (when I have to drive all around town to find the components I need, but thats part of the fun in building something like a good amp).

thanks though, you might hear from me
Jean.

P.S. the following link doesn't work http://www.printedelectronics.com/pe...nks/Conrad.htm

[NU_NRG]

If I were you I'd stop searching and I'd take a look at this awesome amp (ESP project 3A) Search around this amp on the forum I guarantee you'll find nothing but good reviews from DIY'ers.

-Simon

[Jean]

Simon (or anything else who is reading!) have you build that amplifier ? It looks really simple , but how would it compare to Leach or Aksa ?

[NU_NRG]

Although I can't compare project 3A to ASKA nor Leach (haven't build those yet)... IMHO 3A is the perfect amp project for anyone who wants to give a try at DIY and expect to build something powerfull and yet verry stable.

Straight forward amp, no costly or rare component to buy, flexible design, great sound... as it all!

My version of this amplifier hasen't encountered major problem since i finished assembling it. Although I designed my own pcb the sound is awesome and there is no sign of evil oscillation. The only problem with this simple design is that you can't short output terminals with out cooking your transistors.

Just ask if you have anymore questions

-Simon

[Jean]

Simon, do you have any pictures of the assembled amplifier ? What heatsinks and transformer , power supply caps did you use ?

Do you think I could get away with using a couple computer cpu heat sinks ?

[Vivek]

Hi Simon,
Will a handwired version be good enough for the 3A amp because that is what I am doing?
Regards,
Vivek

[hugobross]

Hi Simon,

The only problem with this simple design is that you can't short output terminals with out cooking your transistors.

If you really want to protect your amp against short ciruits at the output, you can simply add a protection circuit to the schematic, it's really simple (about 5 components per channel). OK, there are a few guys on this forum who doesn't like such circuits, because some believe they will have influence on the output signal of the amp. I don't see any reason why such a circuit will do that (under normal conditions of course). DON'T use fuses to protect your transistors, they are simply too slow to handle short circuits.

You can see an example in the included figure.

best regards,

HB.