This 4HP module expands the capability of the Behringer 1027 Sequencer by adding a three channel Sequential Switch, that can generate sequences of 8, 16 or 24 steps. Whilst the Behringer 1050 can be used for the same purpose, it is a waste of a wide and feature rich module, that can be better deployed ..read more

This 14HP module is a re-imagining of the ARP 1013 octave filter bank that was announced in 1970 by Tonus as part of the 2500 Synthesizer but it never made it into production. It consists of eight band pass filters with their cutoff frequency spaced one octave apart, from 63Hz to 8 KHz. The filter ..read more

When Roland developed the System 100M they created a rather nice Dual VCA module (130). This is a fantastic module but the signal path is AC coupled, which means the VCA cannot be used for adjusting the level of CV signals. Although Roland added more modules over time, including a DC Mixer, they never produced ..read more

Overview  Back in 1974 G.D.Shaw designed the Practical Electronics Minisonic 2 analog synthesizer. It was published as a magazine project to build, and complete kits were available from a company called Phonosonics. I was lucky enough to get this kit as a Xmas present in 1974 and I gradually built the whole synthesizer with the ..read more

Elaine Radique is the most famous musician to have worked with the ARP 2500, and she has spent over 25 years making music with this remarkable instrument. Her music is well worth listening to, and a video example is attached below. ARP 2515 Elaine’s ARP 2500 is a model 2515 with 15 module spaces in ..read more

The AM8171 module has four separate channels of signal gates based on a modern analog switch. Each gate can be switched on and off by the CV gate inputs or by putting the mode switch into its upper position (preview). Green low current LED’s indicate when the gate is on.     When Roland developed the System 100M they created a quad signal gate module, the 171, which also had a ton of multiples. The AM8173 module contains the same four signal gates built with modern components, and an onboard LFO clock, making it a very useful sequential switch, for both audio and CV signals. DESCRIP ..read more

This 16HP module is replica of the 24dB Low Pass and 6dB High Pass Filters from the legendary Roland Jupiter 8. This is an OTA design that Roland first used in the Jupiter 4 in 1980, and then added Q compensation for the Jupiter 8. This is a warm sounding filter with smooth frequency control and a resonance that gradually increases up to self oscillation – a sound very reminiscent of the early 1980’s. DESCRIPTION This is a warm sounding filter with smooth frequency control and a resonance that gradually increases up to self oscillation – a sound very reminiscent of the early 1980’s. The origin ..read more

Overview  The Roland 131 was a four channel audio mixer and output stage, that was launched in 1979 along with the core Roland 100M VCO, VCF and VCA modules. It was not part of the base “D Set” system of 5 modules, but Roland sold around 1000 units over the next 3 years. It was particular useful in large multi-cabinet setups, to enable mixing of many sounds into a final output mixer with headphones and 6.35mm jack sockets. I built a couple of 100M clones in 2009 using rotary pots in a FracRac format that predates Eurorack. I designed the AM8131 in 2009 but more exciting filter projects to ..read more

A 16HP Eurorack module which reimagines the Roland prototype of 1978, with a couple of twists. The VCO and sub from the SH-101, combined with the cascaded ladder filter from the Korg Monopoly. This module produces new sounds, completely different to the standard Roland OTA filter. Both VCO and VCF chips are manufactured by Coolaudio. Background In 1978 Roland developed and launched the System 100M with an initial set of 8 modules, including a dual VCO (112) and a single VCO, with a VCF and VCA (110). Roland developed a third VCO module (the 111) as a combination of the VCO and VCF. However whi ..read more

This 8HP module expands the capability of the Behringer 1004 VCO by adding the waveform mixer from the original ARP 1004P. The module delivers all five waveforms independently, as well as mixing them into a single output. DESCRIPTION The AM1004P module enables the Behringer 1004 module to be transformed from a T (toggle) version into a P (potentiometer version). A small daughter board is attached to the rear of the Behringer 1004, and five small wires soldered to the individual waveform outputs. They attach to the middle of each toggle switch, on the rear of the PCB. The daughter board accura ..read more