This site is dedicated to everyone interested in Serge Modular Music Synthesizers
return to "History" main page

Old Serge Modules
(descriptions from a mysterious anonymous donor)

These modules are all from the early days, around 1974 - 76 I guess. They all featured the graphical style of panel layout and fitted on a 1" x 1" grid - only six pots or banana sockets high, but more spacious and they had bigger knobs.

Oscillator - These were the standard VCO before the PCO and NTO came along. They didn't comply with the 1v/octave standard, but had two CV inputs with variable tracking, both positive and negative and a sync input. The outputs were a pair of sawtooths and a waveshaper output, the latter giving manual and voltage control of shape from sine to a "bent" sawtooth. The waveshaper was very similar to the ones in the Triple Waveshaper module.

Filter - The early Serge filter was a simple 2 pole VCF. As with the oscillator, it had no 1v/octave inputs, but a variable scale CV input plus manual controls for frequency and Q. The audio input had level control and there were pairs of highpass, bandpass and lowpass outputs.

Gate - Later called VCA. They AC and DC inputs, linear and exponential control inputs and a manual gain pot. Often found paired with a RING module.

Ring - Unlike the current ring, this version had a DC signal in and no carrier level pot.

Dual Negative Slew (NEG) - The negative slew output follows the input voltage up, but slews it when it falls. The slew rate can be controlled by CV and manually. It will produce envelopes with a very fast attack and variable decay time. For a trigger input it gives an AD envelope, while for a gate input it will give an AR envelope. For an audio input it will behave as an envelope follower, while patching the pulse output to the input gives a sawtooth/pulse oscillator, useful as an audio source or for clocking the sequencer.

Dual Positive Slew (POS) - The opposite of the NEG, the positive slew module slews as the input voltage rises, but follows it immediately as it falls. Additionally, it has start (trigger) and sustain (gate) inputs. The slew rate can be controlled by CV and manually. Can be used as a (VC) sawtooth oscillator, ramp/envelope generator and audio divider. A positive slew and negative slew generator can be used together to create envelopes with controllable rise and fall times.

The POS and NEG were gradually replaced by the USG.

Envelope Generator - A rise/fall envelope generator with voltage controlled duration. The "start" jack behaves as a trigger input and the "hold" input sustains the envelope at it's present voltage. "Window" gives a delayed gate output with voltage controlled delay time for triggering other envelopes etc. The end pulse can be used to cycle the envelope generator as an oscillator.

Keyboard Envelope Generator (KEG) - An ADSR envelope generator with voltage control of all stages and an overall rate CV.

Rate Controlled S&H - Similar to the "stepped" section of the SSG, but without the CV amount pot, cycle out and coupler.

V.C. Slew Generator - Similar to the "smooth" section of the SSG, but without the coupler and with two pulse outputs.

Programmer - An ancestor of the TKB. It was a three row four step controller but without a sequencer. Each stage had a trigger input, a manual push-button three pots and a gate output.
There were three analogue outputs plus a trigger output which only operated when a push-button was pressed, not when a stage was manually triggered. A typical early Serge might have two or three programmers.

Sequencer - This was a ten step pulse sequencer, with clock, hold, reset and manual reset inputs and ten gate outputs. Sequences of less than ten stages could be set by plugging an output back to the reset input, e.g. stage 9 output back to the input to give an 8 step sequence.
It could be used be used to control programmers, to directly trigger envelopes or to generate pulse sequences in conjunction with a Peak & Trough module. The older version had two banana sockets per output, the later version had only one per output. It can also be used as an audio divider.

Peak & Trough - This has two sections, each with four inputs and one output. The peak section would output the highest of the four inputs, while the trough section would output the lowest of the four inputs. The peak section was often used for combining gates from a sequencer, but either section could used to combine waveforms, CVs or envelopes in unexpected ways.

Multiple - Although the panels indicated one input and three outputs, the multiples appear to have just been standard wired multiples. Sometimes jacks were fitted for connecting to external

Send & Receive - Converted from banana socket to jacks (and vice versa) for interfacing to external equipment. Two send and two receive sections per module.

Preamp - For introducing low level signals (e.g. microphones) to the Serge. Unlike the later PRNV, this did not include an envelope detector. Available as a dual preamp or combined with a Reverb.

Reverb - A spring reverb. Features a direct reverb output and a variable wet/dry mix output.
Available as a dual reverb.

Noise Source - These are early versions of the NOI module. Some have the same layout as the current NOI with the old style panel graphics, but others only had the white, pink and s/h source outputs, and have no stored random section. Presumably the stored random roles would be carried out with an SSG or RVG.

Many other modules were available in the early graphical panel style and are still available in a modern version, although the circuits may have been improved and minor features added. For example, the dual processor, dual mixer, SSG, TWS and RVG were all available, but the TWS has gained the "all" switch and the dual mixer gained a jack on one input.

[ top ]