Sonic Chessboard, optical octophonic audio/cv panner (DIY kit)

How it works

Under each of the 64 squares sits a light-dependent resistor. Covering a square with a chess piece or a hand changes how much light reaches it, and so how much of each of the 16 inputs reaches each of the 8 outputs. The board is passive: no power, no software. A strong, bright light above the board works best. Routed to eight speakers, the board becomes a octophonic audio panner, with the chess game steering where the sound goes. You can also use it with CV signals to make complicated patches on a modular synthesizer that are constantly changing while you play a game of chess.

Why I made it

I first made the Sonic Chessboard in a small series for my installation Indeterminate Structures (2023). It follows Lowell Cross’s board for John Cage’s Reunion, where a game of chess between Cage, Marcel Duchamp and Teeny Duchamp decided what the audience heard.

Since the Sonic Chessboard found its way into the world, it has been fascinating to see how people make it their own. Users in Los Angeles, Cologne and Osaka have written to tell me about evenings of octophonic chess playing, where every move on the board sent sound travelling through the room and the game itself became a performance. Hearing how a piece designed in homage to Cage and Cross’s Reunion is now being played in such different places is one of the real pleasures of making these instruments.

The chessboard is not limited to audio. Because it is a fully passive circuit, the 64 light-dependent resistors pass control voltages just as they pass sound. Send a CV source into the inputs, whether a fixed voltage, an envelope or an LFO, and the eight outputs become eight independent control voltages, each shaped by which squares are covered. Patch those outputs into VCAs, filters or oscillators in a modular system, and every move on the board redistributes modulation across your patch.

Building it

Building the Sonic Chessboard takes around two hours. Everything is through-hole soldering, and I designed the PCB with generous pads, so the kit is approachable even if you have only held a soldering iron a few times. There are no tricky parts or specialist techniques involved; what the build asks for most is patience. Beyond that, all you need is a set of hands, a soldering iron, a bit of solder and a flush cutter. The repetition of soldering 64 light-dependent resistors has its own calm rhythm, and by the end you will know your instrument from the inside out.

Specifications

DIY kits are not covered by the two-year warranty, since you are building it and not me. When you have experience with soldering and take your time, it is hard to mess it up, but I am happy to help if your build does not work. Write to me.