This one is based on the Sonic Reducer from http://www.parasitstudio.se. It was a bit challenging to build on perfboard, so I probably should have just bought the PCB and waited for the shipping time from Europe!
I've added relay switching to this build, so that I could use an arcade style momentary pushbutton. This is the first build that I've done with a relay switch. I've used an ATTiny85 controller, which I can program using the Arduino IDE and hardware. I've done a fair bit of Arduino in the past, so this seemed the easiest way for me to go when choosing a controller.
I put laser etched perspex on the top surface of this build, similar to the last one that I completed. With the last build, I had to countersink the inside of the enclosure a bit, so that there was enough room for the potentiometers to stick through. With this build, the enclosure was a better quality, and the metal was quite a bit thicker. I ended up having to countersink a lot of material inside the enclosure, and also on the outside of the perspex, and trim the bottom off the knobs in order to get it to all fit together. That was a bit of a nightmare.
Next time I do one like this, I'll use thinner perspex, or longer thread pots.
The finish has come up pretty well. Riley designed some suitable 8-bit graphics, which has been put on with a waterslide decal. The perspex then goes over the top. To my surprise, the etched writing lights up in the dark, which wasn't planned at all, but I'm happy with that!
Arcade button from eBay (in a pack of 5, so I'll have to find another use for the rest of them).