DIY Kits

George is a Boolean logic module which can supply 6 different logic functions from the two inputs – OR, NOR, AND, NAND, XOR & XNOR. The logic functions are all obtained from 4011 NAND chips configured to deliver the different types.  

Based on the Isolators on the SP-808. They are simple EQ filters, all manually controlled. The core circuit is based on a section of the PGM Isolator, don’t know where that came from, probably a 70s electronic hobby magazine. The input stage boosts...

This is a solid VCO using the SSI2131 chip. It is very stable and will track nicely over 10 octaves. It has the stock outputs; saw, triangle and pulse, along with a pan-pulse waveform. Moldy Rapture was the working title of Jack Smith’s 1963 epic,...

Macrame is a 6 channel mixer with voltage controlled level and panning. It uses two SSI2190 chips to do all the work. You can use the SET pots to operate the level and pan manually, or use CV to get things moving around and up and down. It has two synth...

Logorrhea is kind of a vocal filter; basically it is the back half of a vocoder crammed into 8HP. There are two inputs, 10 filter channels, a white noise channel and a thru channel, to feed thru the original signal(s). It uses two SSI2190 chips to do all...

This module uses the SSI2140 chip which is based on the SSM2040 VCF, with a few updates. The initial concept was to design a module that could switch between a phaser and a VCF. Looking back at old SSM2040 designs, it seems most of the usual...

Pseudo is a pseudo-random binary sequence/noise/tone generator based on ideas presented in Electronotes #76. It can be used in 2 ways: 1. Pattern generator supplying 4 different CV signals and 2 gates. It can be locked into loops of 8, 16 or 24 steps,...

This VCF uses two SSI2144 chips, which are based on ladder filters. It has outputs for each chip and a mixed output. Controls include the usual cutoff and voltage-controlled Q, along with ‘spread’ controls for cutoff and Q. If nothing is...