Category Archives: DIY Synth

DIY Synths, basic oscillator circuits

Highly Liquid MIDI kit roundup!

SK-8Speak and SK-1 Wiimotepikachu
The top quality Highly Liquid MIDI kits have been finding their way into various circuit bending and DIY synth projects. Here is a quick roundup of the latest creations:

Animatronic Barbershop skulls singing Helter Skelter.


MIDIfied Circuit Bent Pikachu from Kaseo.


SK-1 and a Speak & Spell controlled via Wiimote and MIDI and heavily modified SK-8 with a custom filter bank (Schematic for the filter is provided below ). Awesome work! The technology is here and sky is the limit.


MIDI Controlled CMOS Synth

midi cmos synth
Jörg Piringer
was kind enough to post information about his CMOS Synth controller including the Source code and the schematics. In a nutshell the project features a MIDI note to PWM ( Pulse Width Modulation ) micro-controller circuit with LEDs connected to a CMOS oscillators. Similarly the modulating LEDs can also be connected to circuit bent devices that use Photoresistors for pitch control or bend activation. Thanks!


Dorkbot in Chicago, Nov 28th.

Liz McLean-Knight and Mike Una will be presenting at Dorkbot this month, which falls on Wednesday, November 28th ( Tomorrow ). As always, it will take place at the excellent Deadtech, 3321 W. Fullerton Ave. in Chicago, USA.

Here’s what you’ll see:
A self-proclaimed “multi-hyphenate,” Liz McLean Knight–the sole woman behind Quantazelle–is thoroughly immersed in technology, fashion, music, and the often-surprising overlaps between. She will be demonstrating and discussing the art of “micro-sampling” and other swell digital music production techniques. Once she gets going, this whole thing might turn into a dance party.

Michael Una an audiovisual artist whose work “investigates how vibrating waves of energy and human consciousness interact” will present simple-but-effective techniques for controlling audio software and hardware with inexpensive, commonly found devices like QWERTY Keyboards, video game joysticks, and bicycles.

In addition to the knowledge, beer and pizza will be served. Yum Yum. Those who can’t make it, don’t panic. The event will be caught and released into the interewebs.

Home Made Sound Electronics – The Book

This is interesting, apparently after the release of Handmade Electronic Music, Nic Collins did some workshops and was featured with an interview in a book with Andres Bosshared, Bruno Spoerri, and Norbert Möslang called Home Made Sound Electronics. Unfortunately it looks like its only available in Switzerland. The content very much intrigues me, especially this solar powered point to point circuit pictured below. Not much of a description on the page, aside the fact that most of the projects are DIY music related. The ordering site is available in English but the prices are in Swiss Francs. To get this book over the pond all said and done is about $40 USD. The publisher appears legit, but I did have issues transferring to the actual payment page, kept timing out. After my failed attempt I did stumble on to a page where you can request a review copy, so we’ll see if they respond. The book also comes with a DVD, I’m guessing of the workshops. [Found through Sendling blog]

Cellular Automata Synth


This synth is a little hard to describe, but basically it used Cellular Automata rules for generating notes with various parameters being controllable by the knobs. The actual playing interface I find very unique, it consists of 4 touch slide controllers. The entire synth is constructed from Critter and Guitari kits, which are most excellent by the way. Huge Thanks to Tommy of Roth Mobot for sending this in.

Here is a Video of this thing in action.

Minimum Theremin

Andreas has sent me a link to a fairly strait forward Theremin build. I’m not a Theremin guru, but the design seems easy to implement with only 2 4069 Hex Inverter ICs and other inexpensive parts. The description of the circuit operation is a nice read as well. From what I can decipher the pitch of one oscillator is controlled by the capacitance of the body’s relative position to the antenna. Another oscillator is adjusted and set to have a similar frequency of around 73kHz, that is roughly 4 times higher then the normal hearing range. What happens next is the key to Theremin operation. These 2 frequencies are actually subtracted from each other, giving a frequency that is within audible range. This typically is not the way most Optical Theremins work where a single oscillator is controlled by resistance and the resulting frequency happens to be within the audible range. Either way there are lots of cool case designs and info on this page.
An audio sample of the theremin can be heard on this arrangement.


Atari Punk Console + Filter + Amp = Cigar Box Modular Synth

Atari Punk Console Filter and Amp
Tuomo from Finland has posted this neat video on the OikoSulku blog. It contains an Atari Punk Console circuit patched to a Filter stage and then to an LM386 Amp stage. The filter on a square wave synth sounds pretty cool and creates an ADSR Envelope to shape the sound. I dig the little cigar boxes in particular and also the aesthetics’s of the exposed speaker. One time I remember a band whose name I can’t recall was headlining after my band at a bar. Their instruments were 2 laptops and a bunch of speakers turned upside down with mics on them. Needless to say the ambient sounds of the bar crowd getting rowdy ruined any chances for a glitchy micro house set.

MIDI to Potentiometer


Finally the dream of having MIDI controlled potentiometers on circuit bent toys and DIY synths can be a reality with this newest Highly_Liquid MPA Kit. It features 4 independent variable resistance outputs that can assigned values from 100 Ohm all the way up to 100k Ohms via MIDI! But if that wasn’t enough the kit also features 8 Digital outputs that can be turned on and off by MIDI notes. One obvious application for this controller would be to have the digital output pins connected to sound triggering buttons on a toy and the variable potentiometers to the pitch resistor. Instantly a very simple toy would become a dope lofi MIDI drum machine! I’ve always wanted to build something like this, but the research and development time involved into this kind of a project can be tremendous. Certainly for $47 once can bypass all that and get right to making cool instruments.

Product Link.