Power amp?

[drewl]

Any good sites or schems for building a 10-20w output power amp?
Solid state of course.
I have a tube preamp I built into a little ss combo amp I use to drive tube power amps.
I was thinking of building a power amp into it so I could use it as a stand alone amp also,
I figure 20w should be plenty, it only has a 10" speaker.

I could use a typical driver chip like the TDA series in the little Marshalls or Fenders, but was thinking maybe something easier is around using discrete transistors.
Thanks.

[Minion]

Useing a Discrete design would be Much more complicated and expensive than useing say a TDA2030/40/50 Power amp IC.... Most discrete amps that are stable will have at least 50-100 Parts were you can Build a TDA amp with a PSU with about 10-20 parts Max and on a Much smaller PCB.....

I just finnished Designing a TDA 2050 amp that has it"s own on board Power supply and it only has about 12 parts and fits on a PCB about 2.5in x2.5in , I was going to throw a Pedal like the Guv-Nor in front of it and make a simple 30w amp.....I haven"t assembled it yet but I have the boards etched and they just need to be drilled and stuffed with parts....If you want me to share the PCB design with you let me know ,The board will work with many different TDA chips and even the LM1875.....

Cheers

[drewl]

Sure.
I've worked on enough amps with the TDA chips....think I even have a couple around....should be simple.

[Minion]

Well here is the Simple PCB I did for the TDA amp...





The resistor that is Marked 0R is just a jumper.... The Pad Marked CT is were you connect the Center Tap from your transformer and it is also the Ground Point were you would connect the negitive speaker lead , You need an about 2-4a bridge rectifier (depending on what TDA Chip you use) and the 2 Pads comeing off the bridge rectifier are were you connect the 2 hot leads of your power transformer ....It uses 2 x 2200uf Caps for PSU filtering with another 0.1uF closer to the IC power pins ,The data sheet Recomends 220uf close to the power pins but I believe because the 2200uF caps are really close to the IC that extra Filtering will not be needed.....


Cheers

[drewl]

You have a schem?
It's easier for me to read that way.

[geertjacobs]

Check out the solid state guitar amp forum:
http://www.ssguitar.com/

[Minion]

You have a schem?
It's easier for me to read that way.

The schematic is pretty much exactly the same as the app note in the TDA Datasheet.... The only differance is that this that this design has a bridge rectifier and has 2200uF caps close to the IC instead of the 220uf ,Other than that the PCB and the datasheet app note are exactly the same....