i made a prototype of a cheap diy instrument that can be controlled by ableton live.
it's basically a cheap cmos synth (see the schematics after the jump or better read nicolas collins book) that is controlled by a microcontroller that reads midi data.
but you could also control your favourite circuit bent synth you have at home or any other device that works with low voltages.
the midi kontrollor (that's not a typo, it's german) is pretty simple: just a attiny2313 with an optocoupler for midi and some leds. two of them can be controlled by PWM (that means analog out!) but only one is working with the current software.
the synth consists of three oscillators (schmitt trigger with feedback) and two distortion circuits (one with added fuzz). when you switch on the synth you should hear no sound but sometimes you do (mysterious...). you have to connect the oscillators to the distortion circuits either with your fingers or with wires or (best) with the LDRs that react to the blinking of the LEDs.
the sound is pretty unpredictable but fun and surprising (that's because it's unpredictable (that was the last of these parantheses i promise (this should be a description and not lisp))).
by the way: the enclosure of the synth is made of polymere clay that hardens in the oven.
see schematics and source code for the attiny2313 after the jump...
most resistors are between 10k to 1M.
the best thing is to try different values until it sound good/interesting/extreme.
you also use potentiometers or LDRs that are connected with the kontrollor.
Hey Joerg,
I love your work! Thanks for sharing the circuit, I will definitely knock one up next free weekend, fantastic noise music. I think I like it just free without Kontroller, but that is also an excellent idea. Do you know of Peter Blasser's work? http://www.ciat-lonbarde.net/paper/index.html
wooww this is totally awesome. I want to build one for my 40106 based oscillators, but i have no adr programming thingi. Is it possible for you to send me a ic (programmed)?? What is the ISP Thing in the schematic? Is it an IC? Sorry i never used microcontrollers.
btw i live in germany, so we can talk in german. my english is not sooo good...
Thank you so much
Sebastian