WHAMMY #3

Woody

Here's how my made my Wood WHAMMY. I won't go into the BOM too much (see prior WHAMMY builds, and the official WHAMMY thread.

First, I got some cheap 4"x1" pine from a big box hardware store, so I could prototype and practice. I have some cheap power tools, and I'm not all that experienced with fine woodcraft.

Tools:

  • Harbor Freight 10 In. Sliding Compound Miter Saw
    • Get it with the 20%-25% coupon, or just get a much better one from a named brand for $300-$400
  • 1990s sears plunge router mounted on a Bosch router table
  • Dremel with the plunge router attachment. A full sized plunge router would probably work better, but I didn't want to disassemble my table
  • Harbor Frieght Ratcheting Band Clamp
  • Old Skill jig saw

I got 12x8 aluminum plates from OnlineMetals.com. The are cheap, so order extras in case you mess up or want to make a second amp! My wife suggested I use glass for the top, so I might get some later.

I tried box joints, just for the fun of making my own jig, but I decided on miter cuts because the rabbet on the top is hard to do correctly with box joints as the rabbet goes to the wood's edge.

First, cut the wood so that you have 9"x13" box at the outer edges. This will allow for a 1/2" rabbet to lay the top-plate into. I was a little off in my measurements, and as a result, the rabbet is not quite even, so I put that part on the back. Use the Ratcheting Band Clamp (or other box clamps) to test and make sure the box goes together correctly. Mark the joints so you can remember what connects to what.

Route a 1/2 rabbet slightly deeper than the thickness of the aluminum plate

Route a slot about 1/2" above the bottom so you can slide in the aluminum bottom plate

Measure and drill all the holes. For the power inlet, I drilled holes at the corners, then used a jig saw to cut it out. You could also use multiple passes with the plunge router. Make it a little smaller, then use a file to enlarge it to fit.

Use the plunge router on the inside around each hole that needs extra space for wire access.

Once all the holes are drilled and inner space routed, test the box again with the band clamp, jacks, and the aluminum plates in place. Adjust the rabbet and/or slot with the router as necessary.

Note: I mounted the board onto the bottom plate as far to the volume side as possible to place the volume knob as far as possible to the right. You could mount the potentiometer to the front plate then run wires to the board, but you might get EMI interference.

When you are confident it all looks good, it's time to glue. I chose to only glue the two front joints, and use screws for the rear. My theory was to glue it, then unscrew it, then slide the bottom plate with the board attached into the box, then screw the back board back on. This allowed for the easier soldering on the back board since I could unscrew and remove it as needed. You could attach the completed and working board to the bottom plate, slide it in, then glue it all. Up to you. If you are going to preinstall the board, you might want to stain the interier of the box before you glue, if you care what the inside looks like. You should also paint the bottom plate if you care about how it looks.

Once glued (and dried), I then used a 1/4" roundover bit on the router table to round the top and mitered corners. Then sand and stain. Then use poly wipe or some other protectant on the stained wood. I did 15 coats of poly wipe. If you pre-installed the board, protect it!

Solder all the jacks, attach the feet, and enjoy!

Gotta have a blue power light. It's a Pass designed amp!