Cabinet!

The amp is taking shape. It’s about 10 1/2″ long, in case you can’t judge.

I’m sorry I chose to form a chassis from sheet aluminum, because the aluminum is so flimsy. It will work fine in the plywood cabinet I’m building, but I think it would have been better to make the whole thing from wood. I am told the fire risk is pretty low with tubes this small, and I think it would be easier to fireproof the wood than it is to drill and bend a chassis with precision.

It’s funny; sometimes precision woodworking is easier than precision metalworking, but usually, it’s the other way around.

I’ve learned a few things about holes in thin materials. I stupidly figured I could cut nice holes in thin aluminum, using metal bits and Forstner bits. The Forstner holes aren’t too bad, but some of the metal-bit holes are triangular. No one will ever see them, but still. Another thing: I should have pre-punched the metal to keep the bits from wandering. Even on a drill press, bits roam.

Apparently, I should have used knockout punches. These are chisely sort of things that cut round holes in metal. They’re usually used on electrical boxes. I found an incredible tool while researching this. Harbor Freight sells them for $90. It’s a hydraulic pump that attaches to a device that pops holes out of metal. You drill a guide hole, attach a die to the metal and pump, pump the handle, and pop out holes up to 3″ in diameter, in steel up to 1/8″ thick. That’s astounding. And the reviews say the tool WORKS. Think of the hilarious pranks you could do with a tool like that.

I’ve also discovered step bits, and I bought a set of 4.

I’ve been using scrap wood to make the cabinet. I can see why Doug Stowe (the box guy) uses the table saw so much. If you can rout, resaw, and thickness on the table saw, you can save a ton of time and get extremely precise results. The only problem is that there are limits to the types of cuts you can do. And anyone who knows his stuff will realize instantly that you used the table saw.

I cut dadoes inside the plywood to hold the screen and wood panel, as well as the divider between the screen and panel. I also put dadoes in the top and bottom of the divider, which, itself, was created on the table saw. I plan to run a 1/4″ radius router around the whole box when it’s done.

Someone just suggested Tolex to cover it. Maybe I’ll do that. But the wood panel will be lacquer or solid paint. I’ll hose the screen with grill paint. I have to get the rust off somehow. Maybe naval jelly.

I don’t know how to install Tolex, or if it will work with this front panel. I guess I can look at my Fenders and see how it works.

I should be able to get this thing finished and running tomorrow. The speaker hasn’t arrived, but I can use my Super Champ as a cabinet.

This is so much easier than making guitars. I can’t even tell you.

Next amp: a submini I can put in the pocket of my cargo shorts.

Ps. 37:4!

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Something I forgot to post: if you’re trying to fab an aluminum electronics chassis, don’t bother with the souped-up foil they sell at Home Depot. Buy a pizza pan for four bucks. It’s much more rigid, and it will make a fairly big chassis. You can find them at Gordon Food Service or other restaurant supply stores.