small solid state amp schematic

[bobble991]

Im looking for a small (20w or 30w) solid state power amp schematic with a little oomph to build into my pedalboard case. I built a clone of a simple marshall preamp which is terrific. Im sure someone has something nice tucked away that they have used as a practice amp.
Thanks
Bob

[JohnH]

Rather than make one from scratch how about buying an module as a kit from an electronics hobby store? That way you get the parts and circuit board, and instructions. Would need power as well however...

Better yet, get a second hand SS amp from ebay, the sort of thing that people want to get rid of for not much $ when they move up to a better amp. Then you can gut out the power amp part, and also keep the power supply circuitry.

If its just for practice, do you need that much power? As an example, my little 10W MG10 Marshall will drive a 4x12 cab at volumes too loud for the house. The parts that would be needed from it to do what you suggest are on just a few square inches. (not offering it however...)
John

[bobble991]

Ive just stripped down a set of labtec computer speakers. There is a 5 watt amp complete with power supply and a couple of very small 4 ohm speakers. If i replaced the speakers with a couple of 4 ohm car speakers do you think this would be enough? Ill add an lm386 headphone amp as well.
Or how about using an lm3876 amp with the feedback just sufficient to produce 10 watts?

Bobble

[JohnH]

I dont know how efficient car speakers are. also, Ive not used those chips, but this site has some good info on lm386 circuits
www.runoffgroove.com/

See the 'Little Gem' and 'Ruby' amp designs

J

[RJB]

How about an LM4730. About 8W/Channel @ 12V. Stereo w/Bridge capabilities. The LM3876 looks like it wants 15V minimum. National doesn't offer a demo board for this series. Only for the <3W Class D types.

If you're looking for a simple solution. I would look to a computer type, powered subwoofer. Usually more power than the stereo powered speakers.