There are a million and one MIDI controllers and synths on the market, but sometimes it’s just more satisfying to make your own. [Turi Scandurra] very much went his own way when he put together his Diapasonix instrument.
Right away, the build is somewhat reminiscent of a stringed instrument, what with its buttons laid out in four “strings” of six “frets” each. Only, they’re not so much buttons, as individual sections of a capacitive touch controller. A Raspberry Pi Pico 2 is responsible for reading the 24 pads, with the aid of two MPR121 capacitive touch ICs.
The Diapasonix can be played as an instrument in its own right, using the AMY synthesis engine. This provides a huge range of patches from the Juno 6 and DX7 synthesizers of old. Onboard effects like delay and reverb can be used to alter the sound. Alternatively, it can be used as a MIDI controller, feeding its data to a PC attached over USB. It can be played in multiple modes, with either direct note triggers or with a “strumming” method instead.
We’ve featured a great many MIDI controllers over the years, from the artistic to the compact. Video after the break. Continue reading “DIY Synth Takes Inspiration From Fretted Instruments”







The device is inspired by the Theremin, and was built to celebrate its 100th anniversary. The Nanoaetherphone II is all about using sensors to capture data from wireless hand-wavey interactions, and turn it into MIDI messages. To this end, it has an LDR sensor for detecting light levels, which determines volume levels. This is actuated by the user’s thumb, blocking the sensor or allowing ambient light to reach it. At the front of the handheld unit, there is also an ultrasonic range sensor. Depending on how close the sensor is to the user’s hand or other object determines the exact note sent by the device. As a MIDI controller, it is intended to be hooked up to an external synthesizer to actually generate sound.