Replies to This Discussion

Permalink Reply by Paul Craig on March 2, 2017 at 9:00am

Welcome David. What amp are you trying to build?

Permalink Reply by David Blackburn on March 2, 2017 at 10:03am

Hi Paul:

I was using one of these little amp modules and an old computer speaker. I have a piezo taped inside the box and I get a lot of crackling. Not a clean sound at all. It may be a bad amp unit (what can you expect for $1.50?) or a crappy speaker. I think I need to do some more experimenting to try to isolate the problem. It's frustrating, but fun!

Cheers.

Permalink Reply by Paul Craig on March 2, 2017 at 9:03pm

Piezo's can give a lot of "handling" noise and feebback. I usually apply a piece of double sided tape to the area I want to mount the piezo, place it on the tape and put another piece of tape over the piezo.

Computer speakers aren't made to handle instruments and they will distort badly and crap out fast. You need a speaker that's made for instruments and the bigger the speaker - the better the sound because it moves more air.

That amp is probably fine. It looks to be like the typical LM386 based chip amp. It's probably 1watt to 2.5watts output.

Permalink Reply by David Blackburn on March 3, 2017 at 2:10am

Good suggestion re taping the piezo. I'll give that a try.  I don't know much about speakers but since it will be driven by a 9-volt battery I can't imagine I can go too big. But I'll see what I might be able to put my hands on to try.

Thanks.

Permalink Reply by Paul Craig on March 3, 2017 at 8:14am

CBGitty sells some small guitar speakers(at least I think they are guitar speakers). Other companies make 6" -  8" - 10" - 12" speakers with 20 watt max output for guitar(Celestion, Eminence and WGS) that can be bought online for as little as 30 bucks.

Permalink Reply by David Blackburn on March 3, 2017 at 10:56am

Thanks for the info Paul. I narrowed my problem down to a bad amp. I'm going to try another type and if that works then I'll look into getting a proper speaker. Cheers.

Permalink Reply by Paul Craig on March 3, 2017 at 11:07am

There's a couple of good inexpensive little amps you can find online that put out 2.5 to 5 watts. Do a Google search for 5watt guitar amps and a lot of them will show up.

Permalink Reply by Kigar on March 22, 2017 at 2:18pm

Give this thread a try for a decent cheap amp.  http://www.cigarboxnation.com/forum/topics/bought-amp-don-t-have-cl...

Or for low wattage amps without a lot of volume, check out the lm386 based amps.  CB Gitty has some amp kits too.

Permalink Reply by David Blackburn on March 22, 2017 at 3:20pm

Thanks, will check it out.