Moog 904-A Eurorack clone by controlvoltage.org DEMO

Published on Aug 2, 2016 Roberto Raineri-Seith

"A 'quick and dirty' demo of the controlvoltage.org Moog 904-A clone for Eurorack that can be ordered as DIY-project on my website controlvoltage.org (production files only).

The filter is fed with a single square waveform from a Mos-Lab 921-B VCO.

Various settings, initially without, later with frequency control from the same envelope used on the VCA. No attenuators used. Delay and reverb added.

Final note: the module was only roughly calibrated and not all transistors were matched, so for purist there is some improvement margin left ;-)"

See this post from 2012 on the controlvoltage.org 904.A, and this post for another video.

Roberto Raineri-Seith | controlvoltage.org 904-A VCF clone for Eurorack first (rough) prototype test

Published on Feb 11, 2013 birbabirbabirba·36 videos

"The 904-A is fitted with a single Asys RS-95E VCO pulse wave and of course the prototype is only rough calibrated and assembled with standard components. Alpha pots and selected components will be used in the production version, along with a slightly larger frontplate (14 HP). At least the resonance levels must be further adjusted, so there's a little more job for my engineer... For more infos please go controlvoltage.org"

Update: "Audio signal is provided by a single Asys RS-95E VCO pulse wave.
In this first test the prototype is only rough calibrated and assembled with standard components, Alpha pots and selected components will be used in the production version, along with a slightly larger frontplate (14 HP).

First impressions: the frequency response works as expected, but the resonance levels and response must be further adjusted to match the original, so there's a little more job for my engineer..."

Controlvoltage.org Eurorack-format 904-A VCF

"The controlvoltage.org 904-A VCF module is a 3U 18HP Eurorack-format compatible true replica of the legendary 904-A voltage controlled low pass filter from the Moog modular series.

Hand-crafted in Switzerland with 100% discrete analogue circuitry, rugged aluminum frontplate with laser-engraved typography and scales.

Available in Spring 2012 at an estimated price of 250 €.
Pre-order it by email: controlvoltage at bluewin.ch"

via Cntrolvoltage.org

"Also coming in 2012: a complex Eurorack Format quad- triangle-core VCO specially designed for FM"

Note Controlvoltage.org is run by Roberto Raineri who won the latest IDOW & MATRIXSYNTH Modular Pic of the Week.