TDA2822-based tiny guitar amp?

[SeneX225]

Greetings and salutations!

Whilst scouring for some schematics online I've stumbled upon something that pickled my curiosity:



I tried searching for details or schematics, but only TDA2822 amps I found were those phone/mp3 player volume booster types. Is this one the same or is it a proper (although palm-sized) guitar amp?

[garcho]

...or is it a proper (although palm-sized) guitar amp?

Sorry, but no diamond in the rough here. Just a tiny, weak, kinda crappy amp. Datasheets are your friends, it's 0.5W max. To power headphones on cheap consumer audio players? Maybe. Guitar amp? You can find better.

[SeneX225]

...or is it a proper (although palm-sized) guitar amp?

Sorry, but no diamond in the rough here. Just a tiny, weak, kinda crappy amp. Datasheets are your friends, it's 0.5W max. To power headphones on cheap consumer audio players? Maybe. Guitar amp? You can find better.

Aw, shame. Come to think of it, most of one-chip mini amps I've seen are LM386-based, so I guess I should know better.

Thank you!

[antonis]

Maybe with a little help from a couple of complementary MosFets..

[Ksander]

Hi, I actually built an 2822 tiny amp, taking the Ruby amp as example. I called it the Moonstone.

I used the IC in Bridge Tied Load mode I believe. It was just to try things. It works, but the output is not much different than for the Ruby. The 'tone control' doesn't really do much. One advantage over the ruby is that it distorts much less.

[SeneX225]

Hi, I actually built an 2822 tiny amp, taking the Ruby amp as example. I called it the Moonstone.

I used the IC in Bridge Tied Load mode I believe. It was just to try things. It works, but the output is not much different than for the Ruby. The 'tone control' doesn't really do much. One advantage over the ruby is that it distorts much less.

Hello! This is very cool, I like your design!

Would you mind sharing a schematic?

[Ksander]

I never drew out exactly what I made, other than the fritzing drawing.

The circuit is figure 2 from the ST TDA2822M datasheet. The guitar input goes to the buffer from the ruby amp at runoffgroove, then there is a pot which bleeds part of the signal to ground, and the is the datasheet schem. Possibly with an additional cap at the block junctions.

Edit: the circuit is a combination of the jfet buffer from the ruby amp and the BTL layout from the datasheet - just for clarification

[garcho]

Would you mind sharing a schematic?

The layout he provided is clean and clear. You should try drawing the schematic yourself based on that layout. I learned a lot from doing that when I first started building. And if you can't quite figure it out, you're in the right place.

very cool, i like your design

Me too, bravo