This was a just for fun build that has been on my list for a while.
I built a CBG amp shortly after starting this hobby. It was a simple little chip amp based on the lm386 chip. while building the amp I had the idea that it would be really easy to add this amp to a guitar. Nothing new here, it's been done before.
It takes surprisingly few components to build the amp.
Add a battery, speaker, switch and a pot and it still doesn't amount to much. Originally the pot was going to be a volume control for the amp but then I realized I could use the volume control for the pickup instead. Since I already had a hole drilled for the pot I went ahead and used the pot to control the gain of the amp.
I had a few 2 inch speakers in my parts stash that will fit between the neck and the side of the box.
The required holes drilled and cut.
I added the pickup kit from CB Gitty that I've had for a while. The speaker is wedged in the corner between the neck and a block I glued in. With the lid closed the speaker stays put.
With the amp powered up I closed the lid and got a very annoying squeal. The speaker being close to the pickup seemed to be the culprit. I tried a few things and found that by switching the leads on the speaker the squeal went away. I don't know the technical reason but it worked.
This was all for naught, the volume with the amp was only slightly louder than playing acoustically. I ended up drilling a second sound hole and mounting two speakers to the lid beneath the sound holes. This helped a bit, it's still not what I would call loud but with the gain set to max you can get some raunchy distortion and feedback. I built this for fun and that is what it is.....
One of the reasons the amp is not as loud as I expected is there are several versions of the lm386.
The lm386n-1 which is good for about 1/3 watt output, the lm386n-3 puts out about 3/4 watt and the lm386n-4 that puts out 1 watt with an 18 volt supply.
I'm sure I used one of the lower watt versions.
