Maker and musician Pierre-Loup M. has recreated the iconic Minimoog synthesiser — using a Teensy 4.0 and two Arduino Mega Pro boards, plus a keyboard salvaged from an old electric piano.
"The Teensymoog is a re-creation of the legendary Minimoog, using a Teensy 4.0 running the awesome audio library from pjrc.com, and two Arduino Mega Pro[s]," writes Pierre-Loup. "It implements the same functions as the real one, plus or minus a few ones. The keyboard has been taken from an old Bontempi electric piano, everything else is custom build around, comprising the oil-finished walnut enclosure."
The original Minimoog was an analogue design, released by Moog Music in early 1970. Unlike its bulky modular predecessors, the Minimoog — as the name implies - was designed to be considerably more compact, reducing its feature set in favour of bringing prices down. Manufactured for 11 years, and becoming the first synth to be sold in retail stores, the Minimoog remains a much-loved device — and was even given a reissue in 2016 following Robert Moog's restoration as the head of the Moog brand.
"Two Arduino Mega pro are used to poll all the switches and potentiometer and sending any update to the Teensy," Pierre-Loup explains of his digital recreation. "The communication between the boards uses MIDI messages, mainly control change (or continuous control) messages. I've tried to stick as close as possible to the MIDI specification, and using the existing and available control numbers. There are cases where it's not the case (e.g. filter cut-off frequency uses a two bytes control change to increase resolution).
"A Pimoroni's phatDAC is used to output high quality audio from the I2S stream generated by the audio library. A USB B port is mounted on the rear panel so the synth can be connected to anything, as a USB midi device or USB audio device (not available in Arduino IDE for Teensy 4.0 yet, but I know it will come!). There is also provision for (not implemented yet!) MIDI in and out (DIN-5 pins, but maybe 3.5 jack would be a better idea) sustain and expression."
The housing of the synth is created from a mixture of wood and acrylic: A plywood base plate is joined by salvaged walnut — "from a table I found in the street two years ago," Pierre-Loup explains — treated with tung oil, then the control panels and rear enclosure are laser-cut acrylic.