Semi-Modular Noise Synth Demo

This is only a ridiculously small taste of what this thing can do, it's definitely a fucking monster in sheep's clothing. I built this thing as a birthday present for Daniel in January 2014, but he left it at my place all summer so I took it back to Atlanta with me for school, I'll give it back to him sometime. The VCOs are a brutally simple classic lo-fi triangle core ripped right out of the lm13900 app note, modified a bit for sync in/out, range switch, and an output buffer to boost the signal for use as an LFO. The EG is a modified version of the one Ray Wilson designed for the WP-20 mini synth using a 555 timer, and the VCF is a very simple adaptation of the Steiner design which was originally used in a guitar synth, but I found the design on the yusynth page for the old Steiner filter. I also added a buffer to this one to boost its signal level up so that it could be used to modulate anything else. The VCA is another one taken from the wp-20, using just one transistor and one norton op amp, but I removed the lowpass network on the CV input for audio rate modulation and the DC blocking caps on the input and output so I could use it as a modulation VCA as well. I'm very proud of the fact that I got the whole thing to run on just one 9 volt battery without a step-up converter. Here's a picture of the finished circuitry on a protoboard: https://plus.google.com/+Vlazhnyefission/posts/GYUap7dKXEs?pid=6082856395865844770&oid=118412769924153801374

Видео Semi-Modular Noise Synth Demo автора Euro-Car Enthusiast Rally