Building a Tubescreamer 1/3

I got it in my head that I wanted to build a tubescreamer foot pedal. I used a layout and schematic found on TonePad.com. I have heard that someone should attempt to build an FX pedal before attempting a guitar amplifier. I'm not sure that I agree with that. Sure, the build is faster, but everything is so tiny!

I have never messed with circuit boards, and definitely have never etched anything. So, this was all pretty new to me. But, what better way to learn than to just dive in and do it.

I bought most of the stuff from Mouser and Small Bear Electronics. I get most of my electronics stuff from Mouser, but Small Bear did have more reasonable shipping costs for such a small order. Of course, it wasn't too small of an order because I ordered enough to make two, bought some etching supplies, and two high-quality pliers. The weird looking blue stuff that I taped to a piece of paper and printed on is called Press-n-Peel. Using the clothes-iron, I am affixing the image that I printed (borrowed from Tonepad, but heavily edited and re-done in Illustrator).

I cut the board first. It is a fiberglass circuit board with a layer of copper on it. The idea is to cover the traces with toner (and fill in any planks with a Sharpie or other pen). Then, etch all the other copper away. I'm going to be honest and mention that I did not get a good transfer on the edges. I read about 5-6 tutorials on this and they all mentioned that the edges were the hardest part. Luckily, I was able to draw back what was missing.

Here you can see the board about to be etched with a bottle of etchant (ferric chloride). By placing the board into a small amount of the etchant and gently rocking it for about 15-20 minutes, all the copper that you don't want is removed. The plastic tub is nothing special, the etchant doesn't bother it any. I had visions of the ferric chloride eating the entire thing up (including the fiberglass, lol) and having to start over. As it turns out, this part of the process is just as easy as described. Except for the waiting part - that was a little brutal.


Here about 1/2 of the copper has been removed. The traces are protected by the material that the Press-n-Peel left behind (and my pen marks). Apparently this ferric chloride can really stain your hands and rubber gloves are recommended. I didn't do this, but lucked out somehow. The copper etches off from the outside in, so the center part of this board still has a bit of copper all over. The edges are etched perfectly up to the traces.

This process really did take the full 20 minutes or so. But, eventually the board was etched and I ran it under cool water for a while to stop the etching process.

Next, a tiny drill bit was used to drill the holes that the component leads will fit through. Before I etched the board, I did make sure that the components would fit (which is why I re-made my own board layout entirely in Adobe Illustrator). Some of the items just didn't fit right, and I moved some of the things around. This little drill bit looks like something a jeweler would use, I was afraid I would snap it off.

This is such a horrible out-of-focus picture, but here is the finished product. The traces worked perfectly (and I double-checked continuity on quite a few of them with the multimeter). This is easily 1/3 done at this stage. The next step is to start populating the circuit board with components.

--gh