Introduction: Portable Amplifier

By Thewoodshop
About: I started woodworking with my grandfather as a young boy. I continued woodworking through high school, and started woodturning after seeing a turned project in a friends shop. Some of my fondest memories are w…

Portable speakers for your smartphone, electric guitar, and more! This portable amplifier from Trash Amps can be made from, just about anything. I made this Walnut enclosure for mine, but you can use anything from pop cans to mason jars.

Step 1: Face Plate

I started out with a piece of Birdseye Maple 1" x 4". This will hold the speaker, and amp. I used a square carbide cutter to true up the side, and the face.

Step 2: Remount on the Lathe

I used two pieces of double-sided tape, and a piece of plywood to remount it on the lathe in the chuck. I took two of the jaws out of the chuck so I can turn an off-center hole for the speaker. I cleaned up the face with a round carbide cutter.

Step 3: Speaker Hole

Loosen the jaws of the chuck, and move the plywood waste block over 1/4" this will offset the speaker hole. Use a pencil to mark the speaker size, mine is 2". I used a parting tool to cut in 1/2" for the speaker.

Step 4: Remount on the Lathe

Flip the piece over and remount using double-sided tape again, this will be the front. Turn down the front until the speaker hole opens up from the backside. I used a round carbide cutter for this. Then sand it up to 600 grit.

Step 5: Speaker Enclosure

I used a piece of Walnut 5" x 9" for the enclosure. Mount it on the lathe between centers, and use a roughing gouge to true the piece up. Put a tenon on one end that will fit your chuck jaws.

Step 6: Shaping the Outside

While it's still in between centers, shape the outside of the enclosure to desired shape. I used a spindle gouge to do this, and the lathe is running at 2000 rpm.

Step 7: Hollowing Out the Inside.

Make a small recess for the face plate, and hollow out the inside. I used the #1 East Hollower for this. It's a small carbide cutter that reduces vibration, and less chance of catches. There are two different kits, so hollow out enough room for the kit you have.

Step 8: Finish the Outside

I finished turning the outside with a spindle gouge, and sanded up to 600 grit.

Step 9: Optional

This step is optional, and takes some practice. I loosened the jaws, and kicked the piece a little off-center in the jaws. Turn the lathe speed down, (I run it at 400 rpm for this step) and used a spindle gouge to bring it down a bit.

Step 10: Remount

Remount in the chuck by expanding the jaws, and bring the tailstock up to help support it. Turn the tenon off, and sand up to 600 grit.

Step 11: Making the Base

I made the base out of Birdseye Maple as well. The body is 6 1/2" and overall length is 18". I just tried to proportion the base to the enclosure. This may very on the size of enclosure you make. I used a bandsaw to cut it out, this can be done with a jigsaw too.

Step 12: Sanding

I sanded the base with a dual action air sander, but this can be done with a orbital sander too.

Step 13: Drilling Holes for the Amp

The kit comes with a templet for the power switch, and jacks. Find center of the speaker hole, using the templet line up the center hole in the templet. Drill the three holes out with a 1/4" drill bit, a forstner bit works best.

Step 14: Drill the Base and Enclosure

Drill the base and enclosure at a slight angle with a 3/4" forstner bit. This is for the mounting riser, (I used aluminum) but you can use wood if you like.

Step 15: Finish

I used a wipe on finish for this project, it's beeswax and mineral oil.

Step 16: Phone Slot

With a chisel I cut a slot in the neck for my phone to rest. This can be done anywhere along the neck.

Step 17: Glue in the Riser

I cut a 3 1/2" piece of 3/4" aluminum tube for the riser, and glued it into the enclosure and base.

Step 18: Mounting the Amp and Speaker

I mounted the amp and speaker using the supplied hardware. Trash Amps has a great step by step on there website for soldering the components to the board if you buy the unassembled kit.

Step 19: Rock On!

In hindsight I wouldn't of used wood for the plate, it was very difficult to fit the amp. It's designed to be mounted to a thin piece of metal like a jar lid. I had to mount a thin piece of Walnut veneer on the front, because it was getting so thin. I really enjoyed making this project, and happy with the way it came out.