Synth DIY Part 2: The Noise Toaster

For my second project, I chose the Music from Outer Space Noise Toaster. This Ray Wilson design is a little synth in a box; kind of a condensed version of the classic MFOS Mini-Synth (about which I’ll write next). With one oscillator, an LFO, an ASR (Attack/Sustain/Release) section, white noise, and a legit filter with frequency and resonance control, the Noise Toaster looked like a more versatile and interactive device than the Weird Sound Generator. You can let it drone in many interesting ways, but even better, it encourages real-time tweaking. You could perhaps jam with it if you had some patient collaborators.



Here’s a recording of the Noise Toaster jamming with a drummer I know.



So, it was a more challenging project overall. I decided to make things more difficult by only ordering the circuit board and faceplate from MFOS. I felt confident I could source the other components myself because (a) I had two electronics supply stores in my neighbourhood, and (b) Ray’s book Make: Analog Synthesizers includes a whole chapter on building the Noise Toaster, with lots of pictures of the wiring and components. When faced with a wall full of potentiometers at the store, for example, I’d have a pretty firm idea of what I was looking for, and if I wasn’t sure, I could ask the folks at the stores.

Although ordering just the PCB and faceplate was cheaper than getting the whole kit, I definitely did not save any money on the project overall by buying the parts myself. If I’d had the confidence to order my parts online, I might have saved a bit—ordering the three 100k resistors I needed would have cost less than having to buy a bag of 10 at the store—but I learned a lot by going out in person and hunting things down.

The biggest pain, funnily enough, was finding the knobs. The pots I bought turned out to have stems that were too tall for the many cool-looking knobs at my favourite store. I bought a couple that had the old-school Moog style I was after (seen on the filters here), and they just perched on the pots like mushroom caps when I put them on—not flush with the faceplate as desired. Bummer. I did find the right ones once the store got some fresh stock in, well after I’d finished the rest of the project.

Also for this project, I bought a proper soldering station. My first iron had no temperature control. It seemed to get too hot, and the solder would boil. If I was going to be putting in heat-sensitive transistors and diodes, then I wanted to be able to back off the temperature a bit. So, this soldering station joined my mobile workshop. It’s rather dodgy, in that the first one I brought home did not work at all, but the replacement has behaved well since.

The box construction went much better this time. I used a simple design and learned that pre-drilling the pieces before inserting screws prevented the wood from splitting. Who knew? I also discovered a power saw in our shed, and that saved me a lot of time and trouble.

Here’s the result. Like the WSG, it worked straight away. It has an internal speaker, which in theory lets you play the Noise Toaster any time, anywhere. However, the speaker stopped working a couple weeks after finishing the project. I haven’t bothered troubleshooting it because I’m happy just plugging it into my recording interface whenever I want to use it.

Synth DIY, Part 1: The WSG

I was really into building model cars as a kid. My bedroom shelves were filled with 1/24 scale funny cars, dragsters and other exotic miniature automobilia from Revell or Monogram. In the years leading up to giving up the hobby, I was making more elaborate F1 car kits from Tamiya. I loved the activity (and I fully credit my immersion in model kit instructions and diagrams with inspiring my career as a technical writer), but there was a limit to what I could do with the tools and the money and the space I had available. On top of everything else, I was more into rock 'n' roll than farting around with plastic models.

That urge to make stuff has always been there, so when I discovered the world of synth DIY, it seemed like the perfect thing. You mean I can stick together a bunch of pieces from a kit and then make noise with the finished product? Let’s get cracking! I recalled enough of my Grade 8 Electronics class to remember that it was basically super fun to solder. That LED Roulette Wheel I made for my final project didn’t look like much, but it worked from the get-go.

I’d been looking at videos for devices like the Sleepdrone 5, and the idea of a simple noise box really appealed to me. Eventually I found what looked like an ideal first project for me: The MusicFrom Outer Space Weird Sound Generator (or WSG). It had four oscillators that could be tuned somewhat musically, along with LFOs (Low Frequency Oscillators) to mess with the main oscillators and produce various rhythmic/tremolo effects, and a basic filter to produce that classic synth “frequency sweep” akin to a guitarist's wah-wah pedal. The WSG was more versatile than the other drone boxes I’d seen, and it came as a complete kit. The only part I'd have to make from scratch was a wooden case to house the faceplate, circuitboard and clumps of wiring when I’d finished.

I sent my money to Ray Wilson, the genius behind MFOS, and the kit arrived soon after. After buying a few tools (a $20 soldering iron, solder, and wire snips from The Source), I took everything up to my family’s place on Mayne Island and got to work.

[Note: Ray Wilson passed away from cancer earlier this year. Like I say, he was a genius and a true DIY guru. His book Make: Analog Synthesizers was a huge help, and I recommend it highly if you’re thinking of getting into this sort of thing. This series of blog posts is dedicated, with thanks, to Ray.]

Oh, I forgot to say that, in order to reacquaint myself with soldering, I first built a very simple metronome from a kit I got from my neighbourhood electronics shop. Even though the thing consisted of about eight parts, it was still a thrill to plug in the battery and hear it emit a faint “click, click, click”. My Grade 8 regression was complete!

Here are some pictures I took of my WSG build as it progressed.

Preparing the front panel. Everything laid out in true anal fashion.

 

The circuit board's almost done, save for the ICs. Compared to some of the soldering insanity I've put myself through lately, this looks really simple in retrospect!

 

Preparing the front panel.

 

Wiring up the front panel. This is the trickiest part of all the MFOS projects I've done.

A successful first test.

The biggest challenge was building the box. I came up with this cunning angled design, but it turns out that I'm a useless draftsperson and my woodworking skills are no better. You can't imagine how much anguish it caused, fashioning four small pieces of wood together to form a (rough) square. The black paint hides a shitshow of splinters, splits and mangled nail heads. 

Next post: The Noise Toaster.