Monday, March 31st, 2014

Guitar Amp

I got a guitar a while back, but no amp to go with it. So I decided to make my own practice amp mostly using electronics parts that I had lying around. The amp cabinet is based on a vintage Fender Champ (5F1) practice amp that was introduced in the 1950’s. For my version, the cabinet is constructed from a single select pine board and joined together with finger joints. The speaker panel is 1/2″ plywood and holds a single 6″ speaker. The back panel cover pieces are 1/2″ birch plywood with edge banding on the tops. The cabinet is finished with Minwax golden pecan stain and two coats of tung oil.

The amplifier section is my implementation of the Noisy Cricket Mark II schematic from Beavis Audio. The Noisy Cricket amp is designed around an LM386 1-watt audio amplifier chip that is intended for clock radios, boom boxes, etc. The amp circuit is constructed on a small project board with only a few resistors & capacitors as support components. The three knobs control volume, gain, and tone. The switches control power and grit (distortion). The amp is powered from a 9v battery.

Here is a video demonstrating the Noisy Cricket amp:








Click this link for the picture of the plans that I found and used for this project.

Edit: It looks like the Beavis Audio site has gone away. I have put the plans for the amp circuit here.

Edit: Almost 6 years later, now it has a handle! I used a Penn Elcom Tan Leather (218mm), model # H1008-TAN. I used tee nuts underneath to secure it with machine screws.

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3 Responses

December 11, 2014

That is beautiful work!! 🙂
Mind sharing cab project dimensions?

December 11, 2014

BTW that is 8′ speaker?

December 12, 2014

It is a 6″ speaker that I had on hand.The case is 12″ tall, 13.5″ wide, 6.5″ deep at the top and 7.5″ deep at the bottom. I put the picture of the plans in a link above. One other suggestion that I have after looking at the pictures again would be to paint the front of the plywood speaker board black. If you look closely, the black speaker is slightly visible behind the grille cloth. Painting it all black would have solved that.