Synth DB

The Ultimate Synthesizer Database


Total list currently 2405 items in 330 Brands

Moog | Modular


The first Moog modular prototype was built in in 1964, with orders for custom systems being taken as early as 1965, and a commercially available product line by 1967. Moog Music continued to build and sell these analog music machines to universities, studios and musicians throughout the sixties and seventies. Eventually, the technology in these systems was transferred into more compact, portable and affordable synthesizers like the Minimoog, ultimately giving rise to the modern synthesizer.

As imposing as these systems may look, they are merely solid walnut cabinets housing smaller dedicated function “modules” which, when interconnected by patch cables, can be used to create, shape and manipulate electronic sounds into musical bliss. This modular approach allowed buyers to configure the systems to meet their needs or their budgets. The “c” referring to the walnut “console” cabinet. In addition to custom configurations, Moog Music also offered pre-configured systems in a variety of models:

Model Description Years
Synthesizer 1c Limited complexity, designed to satisfy the requirements of independent composers. 1967-73
Synthesizer 1p A portable version of the 1c plus space for an optional sequencer. 1969-73
Synthesizer 2c Moderately complex facilities, suitable for use in electronic music courses or studios. 1967-73
Synthesizer 2p A portable version of the 2c. 1969-73
Synthesizer 3c A large and versatile system suitable for commercial studios. 1967-73
Synthesizer 3p A portable version of the 3c. 1969-73
Synthesizer 10 Most compact system suitable for live performance or small private studios. 1971-73
Synthesizer 12 Same as Synthesizer 10 with new 921 series oscillators and 952 keyboard. 1972-73
Synthesizer 15 A complete studio synthesizer in a portable package. New 921 series oscillators. 1973-81
Synthesizer 35 A compact studio system with basic synthesizer functions. New 921 series oscillators. 1973-81
Synthesizer 55 A total studio system with complete synthesizer functions. New 921 series oscillators. 1973-81

The Moog modular synthesizers use the 900-series of modules. These modules, many of them designed entirely by Robert Moog, are examples of analog synthesis at its finest. The modules are actually quite musician-friendly with straight forward input and output jacks and clearly labeled knobs. There are no technical electronic diagrams silk-screened all over them or esoteric controls. They were very easy to grasp conceptually, making them perfect candidates for music labs and professional musicians alike.

The voltage-controlled oscillator modules produce stunning tones with only one real drawback...drift. Revised VCO modules (the 921-series) were eventually released that offered more stable tuning. But the legend of the Moog sound truly comes from the 24 dB/oct lowpass filter (the 904A). To this day, no one has come close to improving upon the original Moog filter and its patented ladder design. Additional modules include VCAs, envelope generators, highpass filters, equalizers, noise generators, a sequencer, and utilitarian modules such as audio mixers, control voltage processors and power supplies. There is no dedicated LFO module, however. Instead, one of the VCO modules has a rate slow enough (0.1 Hz) that it can be used as an LFO instead of a sound source.

Even the smallest and most compact of the synthesizer systems offered had everything needed for a complete and flexible synthesizer. All systems came with at least three oscillators, while the larger 3p and 55 models had as many as ten oscillators! All systems also featured a remote keyboard controller. Typically 49-note keyboards were used although a 61-note keyboard was used on the larger models. Dynamic controllers were also available, including a nearly full keyboard-length ribbon controller, X-Y joystick controller and foot pedal keyboard. Pitch and Mod wheels may not have been invented yet, but even these early synthesizers had plenty of expressive performance controls. Ribbon controllers and X-Y joystick controllers would continue to be utilized for various control purposes in the decades following the Moog synthesizers.

One common problem with these synths is their incompatibility with the Gate/Trigger systems used in most other synths. Moog equipment, for the most part, used a ‘high-state’ logic called ‘S-trig’ which maintained a +5V until a trigger was sent, and this was done by dropping the voltage to 0. This is the opposite of what’s commonly used in other synths of the time. It also can lead to a problem if a patch used an extensive amount of triggering connections, as each module would cause a voltage drop...and enough of them would send the logic over into low-state and fire the S-trigger. This problem is little-known, and can lead to a good bit of frustration for users who have never worked with Moog products before.

Moog Modules Synthesizer Models (Qty. modules)
Module Type Description 1c 1p 2c 2p 3c 3p 10 12 15 35 55
901 VCO/LFO Voltage-Controlled Oscillator, may used as a LFO or VCO. 1 1 1 1 1 1
901A VCO controller Used to control the frequencies of two or more 901B oscillators. 1 1 2 2 3 3 1
901B VCO Oscillator (sine, triangular, pulse, and sawtooth waveforms) 2 2 5 5 9 9 2
901C VCO output stage Used on earlier Moogs (only 15 made).
901D VCO output stage Used on earlier Moogs (only 8 made).
902 VCA Voltage-controlled amplifier, 2 inputs, 2 outputs, 3 control inputs. 2 2 2 3 3 3 1 1 2 3 5
903 White Noise The precursor to the 903A module, used on some of the first systems.
903A Random Signal Generator Produces white or pink noise. 1 1 1 1 1 1 1 1 1
904 VCF Voltage Controlled Filter used on some of the earlier Moog Modulars.
904A VCF Lowpass The Moog 24 dB/octave ladder filter. 1 1 1 1 1 1 1 1 1 1 1
904B VCF Highpass Range is from 20 Hz to 30 KHz. 1 1 1 1 1 1
904C Filter Coupler Couples the 904A and 904B filters. 1 1 1 1
905 Reverberation Unit Dual-Spring Reverb. 1 1 1 1 1 1
907 Fixed Filter Bank Equalizer. 1 1 1 1 1 1
907A Fixed Filter Bank Equalizer fitted in the Moog 15 and Moog 35. 1 1
909 Power Supply
910 Power Supply Not full height. Designed to fit at the bottom of the cabinets. 1 1 1 1 1 1 1 1 1
911 Envelope Generators This is a full ADSR (Attack, Decay, Sustain, Release) envelope generator. Attack, Decay and Release is adjustable from 2ms to 10 seconds. 2 2 2 2 3 3 2 2 2 3 5
911A Dual Trigger Delay 1 1 1
912 Envelope Follower 1 1
914 Fixed Filter Bank Extended Range Equalizer. 12-band, 125Hz to 5kHz, with high and lowpass knobs. 1 1 1
920 Power Supply
921 VCO/LFO Voltage Controlled Oscillator with a range from .01Hz to 40kHz. Replaces the 901. 1 1 1 1
921A VCO controller Used to control the frequencies of two or more 921B oscillators. Replaces the 901A. 1 1 2 2
921B VCO This 921B oscillator is said to be more stable than the 901B. It has a frequency range of 1Hz to 40kHz. 2 1 4 6
923 Filters Noise, Highpass, and Lowpass filters. 1 1
928 Sample Hold This was a separate device.
930 Power Supply This was the power supply for the Moog 35 and Moog 55. It was wired to the CP8A power switch. 1 1
950 Keyboard Controller 5-octave, 61-keys. 1 1 1 1 1 1
950B Scale Programmer Connect to the 950 keyboard to allow individual tuning of each note on the keyboard.
951 Keyboard Controller 5-octave, 61-note. 1 1 1
952 Keyboard Controller 4-octave, 49-note, Duophonic. 1 1
955 Ribbon Controller Precursor to the 956.
956 Ribbon Controller Continuously manipulates a control voltage. 1 1 1 1 1 1
958 Pedal Controller Optional accessory.
959 X-Y Joystick Controller Optional accessory.
960 Sequencer 3 rows of 8 steps. 1
961 Sequencer Interface Include voltage-trigger to S-trigger and back. 1
961CP Sequencer Interface Panel Designed for the Moog 55. 1
962 Sequencer Switch Used to alternate between the three Sequencer channels. 1
984 Four Channel Mixer Final audio summing device for up to four different inputs. 1 1 1 1
991 Filter And Attenuator Lowpass and Highpass attenuators. 1 1 1 1
992 Control Voltages Routes control voltages from a keyboard or ribbon controller to VCO, VCF, VCA modules. 1 1 1
993 Trigger And Envelope Voltages Route S-Triggers coming from controllers to 911A modules, and also 911 EG trigger outputs to 902 VCA inputs. 1 1 1
994 Multiples Dual jack multiples, permits multiple distribution of one signal to several different places. 1 1 1
995 Attenuators General purpose attentuators to reduce the gain or amplitude of any applied input signal, CV or audio. 1 1
CP1 Console Panel 1 3 CV and Trig outputs. 1
CP2 Console Panel 2 Lowpass and Highpass Filters, Jack Multiples, 3 Control Voltage / Trigger Outputs. 1 1 1
CP3 Console Panel 3 4 input mixer, 2 audio outputs, Control Voltage Switches, Attenuator. 2 2 3 2 4 4 1 2
CP3A Console Panel 3A Mixer featuring illuminated switches that were linked to the VCO's. 3
CP4 Console Panel 4 CV Switches, Attenuator, Trig and Env Routing Switches, 3 CV and Trig outputs. 1 1
CP4A Console Panel 4A CV Switches, Attenuator, Trig and Env Routing Switches, 3 CV and Trig outputs. 1 1
CP5 Console Panel 5 3 CV and Trig Outputs, Power switch. 1
CP6 Console Panel 6 CV Switches, Attenuator, Trig and Env Routing Switches, Jack Multiples. 1
CP7 Console Panel 7 Trig and Env Routing Switches, Jack Multiples. 1
CP8 Console Panel 8 Power switch. For "c" models. 1 1 1
CP8A Console Panel 8A Power switch. For 35 and 55 models. 1 1
CP9 Console Panel 9 Power switch. For 2p and 3p models. 1 1
CP11 Console Panel 11 4-input mixer, Jack Multiples, Reversible Attenuator, 2 CV and trigger outs, and 2 audio outputs, Power switch. 1 1
CP35 Console Panel 35 Attenuators designed for the Moog 35. 1
Some of above systems have a separate page here. Also some reissues. In 2018, the 3c (IIIc) was reissued and only 25 are/will be made.
Engine TypeAnalog
Voices (max)1
LFO1 VCO (model 901 or 921) can be used as an LFO. Range from 0.1 Hz to 15 KHz.
Engine Detailed* Typically 3 to 10 oscillators per system. Range from 0.1 Hz to 15 KHz. Waveforms - Sine, Triangle, Rectangular (pulse), Sawtooth.
Filter (VCF)Lowpass 24 dB/oct VCF. Highpass VCF (20 Hz to 30 KHz). Parametric EQ aka Fixed Filter Bank.
Envelope (VCA)Typically 1 to 5 VCA modules per system. ADSR Envelope generators. ADSR Envelope generators can control VCA, VCO or VCF modules.
FXSpring Reverb
Sequencer3 parts, 8 steps
ControllersRibbon Controller, Foot Pedal Controller, X-Y Joystick Controller
Key typeKeys
Produced:1964 - 1981
Legend: Obvious Y: Yes, N: No, N/A: Not Applicable
VCO Voltage Controlled Oscillator DCO Digital Controlled Oscillator
LFO Low Frequency Oscillator Sub Sub Oscillator
VCF Voltage Controlled Filter VCA Voltage Controlled Amplifier
Velocity As with a piano, the harder you hit a key, the louder the sound, unlike most organs which always produce the same loudness no matter how hard you hit a key. Aftertouch Pressing a key after you activated it. Channel Aftertouch, no matter which key, it will send a Channel message. Poly Aftertouch, sends the pressure per key instead of the whole channel.
Values for OSC, LFO, Filter, Envelope are per voice unless stated otherwise.


If you like to discuss or talk about synths in all forms (including VST and modular), you are welcome to join the Facebook group "The Hard, The Soft and The Modular".

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