On Board Battery Powered Amplifier & Speaker.

[Chuck Cobillas]

Hello All,
I have been building CBGs for several years now, mostly acoustic. I have seen a few videos of people playing CBGs that have a small amplifier board, battery and speaker built in to the CBG. I would like to build one of those, Does anyone have any experience with this? I bought a couple of cheap LM386 (http://www.ebay.com/itm/330941303655?ssPageName=STRK:MEWAX:IT&_...) Amplifier boards on eBay but I'm not too sure if a piezo can put out a strong enough signal to use with it and also, what type of speaker works well with this type of setup?

Any input on this would be appreciated.

Thanks,
Chuck

[David Johnson]

This one has the advantage of a small footprint & pot mounted on/off, volume control.

http://guitarfuel.com/SD2WH_Amplifier_Harness.php

or Gittys, same size...

https://www.cbgitty.com/cubecart/amplifier-parts/2-5w-artec-amp-cir...

These can both be driven with a piezo straight in, no preamp. Though not really loud.

[proudy1959]

Hi Chuck

I built a very simple amp using just 3 componenets, an LM386 chip and 2 x 47uf electrotype caps.

Hooked up with an 8ohm speaker, 9 volt battery and a 1/4" jack socket.

I built this so I could easily test piezo pickups I make, I have not tried this as an onboard but with a little bit of adapting I think it should work, connecting a piezo to the input.

Built on stripborad I have attached some photos and a rough wiring diagram. On the stripboard cut the foil strip under the Lm386 between pins 1-6 leaving 7&8 intact and also cut between connection points of the 2 caps.

Connect all grounds and off you go.

The only disadvantage is the lack of an on/off switch but a simple spst switch could be used.

Hope this helps

all the best

Chris

[proudy1959]

Hi Chuck

Been looking through my wiring diagram and found this I've attached. You can substitue the out jack with a speaker, it does have on/off switch and vol control.

Probably a better option that the first I sent you.

Regards

Chris

[proudy1959]

Just another I forgot, you will have to substitute the in jack with your piezo.

Chris

[Chuck Cobillas]

Thanks for the info Chris. I have a couple of builds I need to finish off before I start another but I am looking forward to experimenting with this.

Best Regards,
Chuck