I would like to walk any newbie to DIY audio equipment through the process of designing and building a mini combo amp for an acoustic guitar.
I would first like to say that this is a very simple amplifier, and is likely too simple for some. Other
than a volume control and an on/off switch, there are no controls on this amplifier. This is just a fun little project for someone who wants to beef up the sound of an acoustic guitar.
The first thing I did was buy a kit for a 3 watt mono amplifier at radio shack. I put it together exactly as the instructions said, and connected two small speakers
to the output. The entire amplifier runs off of a nine volt battery.
Once I had put it together, I plugged in my guitar. The volume was very low, and there was a large amount of distortion. I personally like distortion, but other people's tastes may differ. So to eliminate the distortion, I began to experiment by swapping out resistors
. These are easily found in broken radios and such. It took a little while, but eventually I was able to make it produce a relatively distortion-free tone. When you do this, however, you should not use capacitors or resistors of exceedingly different values than the ones provided with the kit. If just replacing these components doesn't change the sound enough for you, try connecting more than one capacitor or resistor in series or parallel. Many articles on this can be found elsewhere online.
Once the amplifier sounds how you would like it to, it is time to put it in a case. I used a large mint tin, as it was all I could find. The actual amplifier is no bigger than 2x2", but it also includes a battery and a switch, and a potentiometer if you choose to use one. If you want to put the speakers in the same box as the potentiometer you will need a bigger and deeper case, but this should not be too hard to acquire. The package that the kit came in originally might even make a good case.
When your amplifier is housed in a good casing, you are done your amplifier. I found it to be very rewarding project, considering the time spent, money paid, and the end result. If anyone has any questions or other feedback, feel free to contact me at firstname.lastname@example.org