Project: State Express Noisebox

Having met with some success at last with building modules for my synth, I thought it would be fun to get back to why I started, and pick something at random from the Nic Collins bible. I went with his crazy 4093 synth.

It's been a long time since I'd even had the breadboard out, so was nice after taking ten minutes to identify the chip on the board (should have known - it was a 40106), I started dig for materials. All the jobs that seemed more problematic before seem easier now - stripping wires, soldering pots and all the rest. I made use for the first time of the solder tip tinner/cleaner that comes in little pots. The bit was the first one on my new iron, which quickly discoloured and became unusable almost immediately I got it. The tinner immediately cleaned it up, and in tandem with the crazy wire wool pot I'm now using rather than a wet sponge, soldering was quicker throughout the day.

Obviously, dry-running the noisebox was important, and I found my crappy Behringer EQ pedal straight away, but took the best part of an hour to find the little battery powered amp (it has been a long time since it was needed). The breadboard version didn't take long to get making some noise, and became a lot more fun when additional LDRs were added so all the four pairs of gates available started interacting with one another.

I started the actual build quite quickly, but it took a while. My aim was to build this into a little cigarette tin I picked up at a market a few weeks. The tin is small, may 100mm x 65mm x 10mm, and the first thing I did was hack my smallest padboard so there would be clearance to close the lid. I decided a I wanted a switch for the battery, and messed about trying to work out the best locations for everything. I also decided to swap a couple of the LDRs for potentiometers. I used some random reverse log taper 100k pots I had lying around, as well as a linear 1m pot for the first gate. I also added the super simple low pass filter for kicks (just a low value capacitor and another LDR).

To get holes in the tin, I pierced the thin metal with a bradawl, then made the holes the right size with a recently purchased reamer. Very simple.

The build on the board is pretty ugly, and like the more elegant PCBs I've assembled recently, I forgot about half a dozen jumpers, so took a while to get it fired up. I think the most criminal mistakes I made were with the power. First, I cut the wire from the board to the switch to short, then forgot to add the ground bus in properly, before realising I also hadn't connected the positive power properly either.

It's a quite fun to play, tho not necessarily one which will become my main instrument.... That said, the main aim when I started was to fit a noisebox into a cigarette tin, so passed there. It was also nice to try and assemble something (almost) from scratch. As much as I still find it hard, there is an element of 'paint by numbers' to building units from PCBs and instructions, so was nice to go off track a little...



 State Express Noisebox   the guts 
 State Express    the finished box