"Moog" Modules - Oddballs

These are eurorack reproductions of rarer Moog (early and custom) modules.

As with my other "Moog" eurorack modules, these complement the Behringer "System 55".

The general design philosophy behind these is:

• "Moog Modular", but in eurorack format.
• Modify the Moog designs only to correct errors.
  
• Support the Moog Modular workflow
  
• Panel aesthetic matches the Behringer “System 55” modules.
• Use of through-hole components (where possible) and the standard eurorack power supply. 

I can supply panels for all of the modules below. These are 2mm aluminium, anodised black with natural aluminium graphics (all production panels include the vertical side "stripe" to match the Behringer System 55 modules) and are manufactured in the UK.

I try and keep a stock of the more popular panels - see below for current stock levels. Some panels are  "made-to-order",  the lead time for producing these is normally 2-3 weeks.

See page "Moog Modules" for the more common modules.

901C "Output Stage"

The 901C provides waveform amplification to allow a 901B (or 901) Oscillator to be used as a modulation source. It also generates positive-going and negative-going pulse waveforms (for "trills" etc.). There are two complementary outputs.

8HP, single PCB design with easily obtainable through-hole parts.

The original Moog module is rare - only about 15 were made.

The  Moog module used a 3-pole 6-way switch, which is expensive and not suited to the smaller Eurorack format. My design substitutes an electronic switch for the output switching, all other parts of the circuit are as the Moog original.

Can also be used with Behringer 921B or 921 Oscillators!  

901C Build document 

901C PCB  Reduced Price GBP 4.00, or free with any order of 901A  and 901B,  or with 901 PCB sets, while current stocks last. (5 in stock).

(Note: the slots for the jack socket pins are not correctly cut, hence the reduced price offer. The build document shows how to modify the PCB.)

901C 8HP Panel GBP 20.00 (0 currently in stock, please email if interested)

                                               (2 "B grade" (no stripes) in stock at GBP 12.00 each) 

995A Reversible Attenuators

This module is a Eurorack implementation of the Moog 995A reversible attenuators, or “attenuverters” in modern terminology.

As far as I am aware, this module was produced as a “special” for the Keith Emerson Moog Modular, and therefore included in the recent reproductions.

The module uses my interpretation of the Moog op-amp based attenuverter circuit based on the CP3A PCB.

 The following build options exist when building this module:

• Normalising of the lower two circuits to the input above.
• Normalising the top circuit to a reference voltage, with various reference voltage options.

995A Build document 

995A PCB Price GBP 8.00 (10 in stock)

995A 8HP panel GBP 20.00 (5 in stock)

Triggered Controller

964 Triggered Controller

One of a number of custom modules that Moog made for the University of New York CEMS system in 1969.  Also known as the "one step sequencer".

The module generates three controllable output voltages actuated by either push buttons or V-trigger inputs.

This design is derived from pictures of an original module on the modularsynthesis.com website. The Moog PCB for this specific module had been modified to provide negative output voltages; the assumption being that as originally designed it generated positive voltages.

In my implementation, the output range for each potentiometer can be configured using jumpers.

964 Build Document

 

964 PCB Price GBP 8.00 (7 in stock)

964 8HP panel GBP 20.00 (1 in stock)

"Emerson" LFO 

Emerson LFO

One thing missing from Moog Modular systems is a simple LFO. Moog expected users to use the 901 (and later the 921) VCOs for LFO duties.

However, Keith Emerson’s custom Moog system did include three simple triangle/square LFOs, which is the inspiration for this module.

As in the original, the panel represents a “converted” 902 VCA panel, complete with “dymo” style labelling.

-          Outputs:

o   Triangle: ± 3V

o   Square: ± 4V

-          Typical Frequency ranges:

o   Low range: 0.06 to 2.5 Hz

o   High range 0.2 to 17Hz

o   Use of the CV inputs will extend these up to approx 35Hz

Emerson LFO Build Document 

 

LFO PCB GBP 8.00 (7 in stock)

LFO 8HP panel GBP 20.00 (1 in stock - panel cut-out is for APEM toggle switch).

Parts for LFO:

APEM toggle switch (as pictured) GBP 4.90 (2 in stock)

CA3080 OTA Original RCA brand, new/unused old stock (NOS) GBP 4.00 each 

902-A Bandpass Filter Adaptor

902-A Adaptor

This is a Eurorack reproduction of a very early R. A. Moog Modular (5U format) filter module from 1964-1965

It is not a stand-alone module, but an add-on for a standard (in this case Behringer) 902 VCA that turns the VCA into a voltage controlled band-pass filter.

It is not known whether this is an accurate reproduction of the original Moog filter, as it is based on photos of a single module, and no original Moog schematics are currently available. As such, the module should be considered “experimental”.

902-A Build Manual (PDF)

902-A PCB  GBP 8.00 each (10 in stock)

902A PCB + Daughter PCB for 902 GBP 12.00 (10 in stock)

902-A 8HP panel GBP 20.00 (made to order)

 Future Concepts:

Sequencer Controller. The "963" Sequencer Utility module from the University of New York CEMS system for use with the 960 Sequencer and 962 Sequential Switch.

Frequency Divider. A module from 1969/70, giving a /2 to /16 pulse output. Looks like only two were made (serial numbers 1016 and 0003).

For orders and enquiries, contact me at enquiries@fitzgreyve.co.uk