Well, my brother wanted a small bass amp, so I figured a TDA2003 circuit would work well...well, no. It sucks actually lol. Virtually no useable clean headroom, I would dare say the lm386 is better. Its no looker either lol.
(http://cordova.asap.um.maine.edu/~raymondj/imagehost/TDA2003inside.jpg)
(http://cordova.asap.um.maine.edu/~raymondj/imagehost/TDA2003outside.jpg)
**edit**
I should say that it worked pretty well with guitar. However, I like the lm386 better even though its not as loud.
Have you tried it with a strong(1 amp or better) supply? That'll get you more headroom.
RDV
Yeah. I tried it with a 10AH 12v battery, then 18v AA, neither one made a huge difference, although the 18volts was louder.
I am also working on a tda2003 based amps i found that if you change the 2.2 ohm resistance for a 68 ohm and the 220 for 1k you get a clean sound. There is still some work to be done but really can play clean bass ,may need some type of freq cut off because at max volume it distorts a little when you play the big string. I use it to drive a speaker with amp sim pedal and fx .please post if you know how to fix big string issuse .
Dear JoeCool. I think thay your BIG problem was not so much with the amp chip itself, but with the speaker. Guitars work anywhere, bass guitars don´t. Please try it again (powered by the 12V battery) with two 6 or 8 inch woofers, 4 ohms each, in parallel (yes, the optimum load is 2 ohms), in a closed box at least 10" deep (WxH depends on speakers used). You´ll see that the result is more than usable. (No, not with a drummer ) Please try it and post the results . MP3s and pictures would be most welcome.