Lured by the siren song of modular synthesis and DIY electronics, but not sure how to navigate the piles of requisite knowledge – or uncertain what the trip down this rabbit hole might have in store?

For years, Tom Whitwell’s Music Thing was a beloved daily read, as that site and this one were among the early blog-format destinations for music tech. Tom moved on – something about a major day-gig at a paper called The Times, perhaps named after the font? – but that makes us all the more delighted to get a dispatch from him. In this guest column for CDM, he introduces one project, a brilliant FM radio sequencer, but also helps us catch up on reading on modular synthesis and electronics dating back to the origins of the technology. And he has a realistic look at what this will do to your life – all inspired by “pure enthusiasm,” as he puts it, “this is fun, you should try it.”

Hey, isn’t that what the drug dealer said in those just-say-no instructional videos we watched in the 80s? Coincidence, I’m sure. -PK

Since buying a Eurorack modular synth a year ago, I’ve spent a lot of time building DIY synth modules and reading about synths and the people who build them. (See reading list, below, if you’d like to do the same.)

The hardest part of DIY electronics is starting out. My first step was building a few guitar pedal kits and learning by reading the Beavis Audio site. Other people start with noisemaker kits like the Atari Punk Console or circuit bending. They all lead in the same direction — down a very deep rabbit hole. 

There’s a lot to buy – a kind of infrastructure you need before doing anything – soldering kit, a multimeter, and a stock of components. None of it costs much, but it’s hard and disconcerting to buy. Online megastores like Farnell or Mouser will stock 50 versions of every component. Get the part number wrong, and you accidentally order capacitors as small as grains of sand, or as large as golfballs. Smaller stores – in the UK, I use http://www.bitsbox.co.uk/ - are easier because they only stock common hobby-friendly parts. 

After making a few guitar pedals, I moved onto synth modules. They’re a great DIY platform. The infrastructure is all there, in terms of power supply, case, inputs, and outputs. Parts are cheap, there’s a healthy and helpful community, and a nice learning curve, from basic utility modules to mind-bendingly complex frequency shifters and vocoders. 

In a year, I’ve built:

• a super-simple, chiptuney oscillator
• a tiny spring reverb driver
• a stupidly-complicated and blinkenlights-covered Arduino-powered Euclidean beat sequencer
• a very useful Arduino MIDI clock
• and a simple but handy 8-step sequencer (see video, below)

For this project, I was inspired by this quote from Don Buchla, the legend of west coast synthesis: 

“My studio at that time was ten feet wide. It was so crowded in there we hauled the workbench out on the sidewalk on good days and set up my oscilloscope and worked out there. [John] Cage came by and for voltage control I had hooked up my keyboard to an FM module that I’d built, a little module that was an FM receiver and I could play stations on it because I had one of the first varactor tuned FMs. Cage, as you can imagine, was just enormously interested in the fact that I could tune each key to a station and then proceeded to play the radio” ( Source [PDF] )

Thirty years later, Don released the 272e module (see Matrixsynth on the announcement), a $ 1250, four-channel polyphonic FM Tuner. There’s also the ADDAC102, a very fancy stereo €270 Eurorack module [see Synthtopia, with a video]. I wanted something quick, cheap and easy that would let me follow in Don and John’s footsteps. After a lot of searching and a few dead ends, I found the wonderful video demo, below, of a battery-powered FM sequencer based on a €15 radio kit from Germany. 

Projects like this follow a predictable curve. There’s a burst of experimental excitement at the start; receiving the crucial part, building the circuit on breadboard and realizing that — YES! — it’s going to work. 

Then comes a period of frustration and tedium. Re-buying a crucial part you blew up. Fiddling with the circuit so it responds just how you want it. Transferring the breadboard layout to a piece of perfboard, or designing a PCB and waiting for it to be made in China. If you’re using an Arduino or other programmable controller, there’s a long period of writing code, battling feature creep, debugging. 

During this period, you have to really, really want the thing you’re making, dreaming of how cool it will be, how much fun you’ll have playing it and telling everyone about it. 

Tom's FM radio-sequencing module project, in all its glory.

Building music gear is more multidisciplinary than you might imagine. The interface and the feel is as important as the functionality. My Euclidean sequencer is a cool-looking thing, with a big LED matrix. It’s really useful – turning trains of pulses into Afro-Latin rhythms. But it’s fiddly and annoying to use. The FM Radio module could be 50% smaller – and size is important in any modular synth – but this time I wanted good big knobs for fine tuning the signals and control voltages. 

So, as the project continues, you’ll spend time designing a front panel, deciding how many knobs you need, removing ones you’ll never use. And along the way, you’re learning. This time round, I wanted to get the control just right – precise, stable tuning so that stations would stay locked. That meant experimentation and [asking for help on the MuffWiggler forum]. I also spent ages reading ham radio sites, trying to work out how to make a voltage-controlled Shortwave radio (I gave up). 
Eventually, the lacquer is dry on the panel, the parts are all in, debugging is complete and the module is working. The result: either elation and fun, or almost immediate maker’s remorse. It’s bad enough spending money on a piece of music gear that you never love. It’s really annoying spending time building one that you can’t then flip on eBay. 

So far, this FM module is pure fun, an injection of random audio in the heart of the system. Every time I turn it on, something else comes out – pirate dubstep stations, Turkish music, news reports and Bryan Adams. You can filter it, sequence it, use it as a noise source, or let it modulate oscillators or open filters. Listen:

Radio sequencer 2 by MusicThing

Photos of the module:

Reading List

Great online resources for learning about modular synths and the first golden age of experimental electronic music include: 

Ubuweb’s electronic music resources section 
Also at Ubuweb, several editions of Electronic Music Review, a beautifully-designed but short-lived journal boasting Robert Moog as Technical Editor. 

The Red Bull Music Academy includes long, detailed interviews with Don Buchla, Tom Oberheim, Peter Zinovieff of EMS, Robert Moog and Morton Subotnik.

Synapse magazine was a mid-70s journal of electronic music, where you’d find DIY projects from people like Serge Tcherepnin

Vasulka is a huge and rather poorly-organised archive of documents, interviews and transcripts, containing some gems.

Source Magazine was, back in California in 1967, a plush avant-garde journal. Many editions came with 10″ vinyl records, pages printed on transparencies or fur. John Cage was a guest editor, and the magazine carried experimental scores from composers like Steve Reich. Original copies sell for $ 500+, but the articles and scores have been collected in a book: 
Source: Music of the Avant-garde, 1966-1973 [Amazon]

What’s Next?

Tom is already on to the next build since he finished up the radio sequencer. This time, it’s a shift register sequencer. A what?

A 16-step random sequencer, something between the Wiard Noise Ring, the CGS Gated Comparator and Nav’s BITSY.

It takes random noise to fill up 4 x 4 step 4015 shift registers, shifted by a clock input. The shift registers are looped – either after 8 or 16 steps. 8 of the steps are fed into a DAC0800 analog/digital converter, which produces a 0-8 volt output.

See also the prototype:

AudioProFeeds-1