"Serge Modular" is an analogue modular synthesizer system developed by French composer and electronic designer Serge Tcherepnin in the 1970s at The California Institute of the Arts. Serge's vision to create a "people's synthesizers" led to a unique modular music system with an iconic design.
In collaboration with and under licence from Serge Tcherepnin, Random*Source offers a range of Serge modules, combining the original Serge circuits with the advantages of today's technology. Original dimensions ("4U" panel height) and the typical look and feel of banana jacks, classic knobs and the grid arrangement of panel elements are preserved.
The modules on this page are all in the classic Serge format - dimension ("4U" panel height) format The modules on this page are all in the classic Serge dimension ("4U" panel height) with classic Serge dimension ("4U" panel height) and the typical banana jacks.
Looking for Serge in Euro (3U)?. Check out our Serge for Euro page.
The TRIPLE WAVESHAPER (TWS) is a non-linear modifier which can transform a sawtooth wave into a sine wave. This classic module incorporates three independent waveshapers for modifying synthesizer waveforms or for processing signals from preamplified instruments. Although originally designed as a waveshaper for early Serge oscillators, this module has been found to be a excellent modifier of electronic and acoustic sounds, and is highly recommended for subtle timbral modifications beyond the range of simple oscillator/filter patches.
The R*S version extends the classic TWS concept:
The Random*Source version is a licensed and authorized adaption of the original Serge design.
The 2017 RING is an improved version of the late Serge Ring Modulator (R9), designed by Serge himself for Random*Source in 2017, more than 40 years after the launch of the Serge Modular system. According to Serge, the RING is one of the most sophisticated modules in the Serge system. The new version has been developed by Serge for and in close cooperation with Random*Source.
Some details of the Random*Source TWS+RING module:
The TWS+RING is available as a DIY (semi-)kit or - upon request - as complete (built) module. The kit contains:
*** This is 4U format - not eurorack! ***
The Serge Wave Multipliers, one of the essential modules of a Serge Modular system, dynamically process the input waveform to produce new harmonically-related overtones. According to the 1982 catalog, "The nearest we can come to describing the unique sound qualities (there are three different sections) is to say that they alter the timbre in exciting new ways, producing interesting alternative forms of signal processing which are unique in the Serge Modular Music System. Since there are three entirely separate and different types of Wave Multipliers in this module, an enormously varied palette of new effects can be synthesized."
Again to quote the catalog: "The Serge Resonant Equalizer (EQ) is a unique ten-band filter designed specifically for electronic sound synthesis and processing. Except for the top and bottom frequency bands, all other bands are spaced at an interval of a major seventh. This non-standard spacing avoids the very common effect of an accentuated resonance in one key, as will be the effect from graphic equalizers with octave or third-octave spacing between bands. Spacing by octaves will reinforce a regular overtone structure for one musical key, thereby producing regularly spaced formants accenting a particular tonality. The Resonant Equalizer's band spacing are much more interesting, producing formant peaks and valleys that are similar to those in acoustic instument sounds.
New: Resonant EQ now in a new version by Random*Source - SMT - with lots of fancy parts.
The Random*Source DIY Kit contains:
The VCM/Res-EQ 4x4 module is available as a DIY kit (see content above - not a "full kit") or as a complete and calibrated module (including fine part choices such as low tolerance Styrene caps in the resEQ)
4x4 module: € 750 AVAILABLE (may take 5-10 days)*** This is 4U format - not eurorack! ***
The NTO is Serge's legendary and most ambitious oscillator. The R*S XFader is an equal power design using highend THAT VCAs and features a variable VCA character to emulate the behavior of vintage Serge VCAs.
The new NTO by Random*Source has been developed in close cooperation with Serge. It took about 2 years to replace obsolete parts and bring the NTO to SMT with some optimizations (precision references and parts) for stability. It also features a new Pulse Out (square wave) in addition to the classic outputs.
Some details of the Random*Source NTO module:
The NTO is available as a DIY (semi-)kit or - upon request - as complete (built) module. The kit contains:
*** This is 4U format - not eurorack! ***
The Serge Dual Universal Slope Generator (DSG) can easily be defined as the essence of Serge and the west coast approach. Probably the most versatile analog module ever designed, often copied, never reached, is now avaulable in an XL version, that never existed before: it contains a full Serge DSG mk2 as well as:
While the regular DSG is already a massive, complex (dual) oscillator, the XL version adds a number of new dimensions. The PEAK and TROUGH can be used as a pseudo-VCA, a mean drone-machine, for effects similar to ring modulator or for prseudo-stereo outputs.
The DSG mk2 version has been optimized for audio performance and speed/precision. The top section covers a frequency range up to more than 10kHz. It also offers improved tracking (up to 4 octaves or more) and some temperature compensation.
DSG mk2 XL is available as complete module (built and calibrated) or a DIY (semi-)kit (comprising a 2mm aluminum front panel and 2 pcbs with all smt parts already installed, but no other parts - this is not a full kit!).
*** This is 4U format - not eurorack! ***
“Carnivore” combines three key Serge modules in only 4 inches: a Serge Smooth & Stepped Generator (SSG), a Serge Noise Source and a Dual Universal Slope Generator mk2 in a slim, oscillator-oriented version covering the functionality of what’s sometimes called “VC TIMEGEN” oscillator (and more). The SSG is a complex multi-functional module which can be patch pro- grammed to provide various slew and sample functions. The Serge Dual Universal Slope Generator (DSG) is probably the most versatile module of a Serge Modular system, incorporating a wide range of functions for both CV and audio. Serge Noise Source provides both white and pink noise waveforms as well as a S/H SRC that generates a special (“noisy”) waveform as an ideal input for Sammple & Hold functions to produce random voltages of equal probability.
The DSG mk2 version has been optimized for audio performance and speed/precision. The left side covers a frequency range up to more than 10kHz. It also offers improved tracking and some temperature compensation.
Some details of the Random*Source "Carnivore" module:
*** This is 4U format - not eurorack! ***
This 4x4 module combines a Dual Universal Slope Generator mk2 in a slim version with an Extended ADSR. The Serge Dual Universal Slope Generator (DSG) is probably the most versatile module of a Serge Modular system, incorporating a wide range of functions for both CV and audio. This 2" incarnation is powerful both in the audio range as well as clock and envelope generator. Thanks to the audio inputs, it can also be used as a filter / LPG. The DSG mk2 version has been optimized for audio performance and speed/precision. The left side covers a frequency range up to more than 10kHz. It also offers improved tracking and some temperature compensation.
The Extended ADSR is a complex envelope generator that not only uses the four segment envelope normally encountered in synthesizers, but is designed with extra features such as an initial voltage controllable delay time, voltage control of each segment, switchable slope forms, and a master voltage control. Each segment may be manually set and voltage controlled. In addition to the normal Attach, Decay, Sustain, and Release segments, an Initial Delay time is included. A master 1V/OCT inout allows to control all slope times for effects such as decreasing the entire envelope time as the pitch of an associated oscillator increases - a phenomenon is typical of many acoustic instruments.
Some details of the Random*Source DTG-ADSR module:
"Slopes / ExtADSR" is available as a DIY (semi-)kit or - upon request - as complete (built) module. The kit contains:
*** This is 4U format - not eurorack! ***
CURRENTLY SOLD OUT!
The Serge Dual Universal Slope Generator (DSG) is probably the most versatile module of a Serge Modular system, incorporating a wide range of functions for both CV and audio. Some functions for which one Slope Generator can be used: VC Transient Envelope Generator, VC LFO, VC Portamento device, Envelope Follower (Detector), VC Pulse Delay (Monostable), Sub-Harmonic Series Generator (Divider), Audio Oscillator with variable waveform symmetry (saw to triangle), Non-Linear Audio Processor (low-fidelity VCF).
From the catalog: "The Universal Slope Generators are unity gain voltage followers with voltage controllable slopes. The range of control is exponential, extremely wide, and the Rise and Fall times can be controlled independently. The range of the Slope Generator is from sub-sonic to high audio frequency. Trigger inputs and trigger outputs allows each section of this dual module to function as a transient (envelope) generator, pulse delay, or in a "cycling mode" (to produce an LFO or clock). Since the Rise and Fall times are voltage controllable, this adds another dimension to the above functions.
The DSG mk2 version has been optimized for audio performance and speed/precision. The top section covers a frequency range up to more than 10kHz. It also offers improved tracking and some temperature compensation.
Some details of the Random*Source DSG mk2 module:
The Random*Source DSG mk2 comes in 2 variants which differ in the top section (only):
*** This is 4U format - not eurorack! ***
Stereo Mixer V1.2 in SMT with balanced outputs:
The combination of the extremely versatile Serge Variable Q Filter (VCFQ) and the R*S Stereo Mixer / Panner is an ideal output module which combines high-end audio specs (including balanced outputs) with massive sound-shaping power.
The unique Serge Variable Q Filter (VCFQ) is an excellent general-purpose VCF that provides simultaneous low-pass, high-pass, band-pass and notch (band-reject) outputs combined with unique flexibility. Its trigger in, LOW mode and self osciallation allow a variety of uses from Oscillator to VC processing. With the support and approval of Serge Tcherepnin, the Random*Source version of the filter uses high-end VCAs by THAT for superb audio performance.
The Equal Power Stereo Mixer / Panner by Random*Source is designed to emulate the behavior of the famous Serge VCAs. It uses some of the best audio components available today including THAT2180 VCA chips. Version 1.1 contains a number of additions and improvements that were adopted in surface mounted technology (SMT):
*** This is 4U format - not eurorack! ***
The Serge Sequencer / Programmer 8 (SQP8) can be used as a push-button, manual programmer and/or sequencer. The pushbuttons not only allow to select a certain stage, but also to set the length of the sequence in performance while a sequence is running. Other sequencieng capabilites include RESET, UP/DOWN and HOLD pulse inputs as well as a GATE output which allows to use the pushbuttons as a simple mini-keyboard. Another unique feature is the A minus B output which outputs the difference between the A and the B output.
The R*S version is optimized for speed and use in the audio range. This allows the use of the sequencer similar to a wavetable oscillator - using a clock of 8kHz (eg from a DSG mk2) generates output waveforms with a base frequency of 1kHz that still have sharp edges.
Some details of the Random*Source Sequencer module:
*** This is 4U format - not eurorack! ***
The Serge Smooth and Stepped Generator (SSG) is an essential Serge module with an enormous variety of uses both for CV and audio. According to the 1979 catalogue, “it is a complex multi-functional module which can be patch programmed to provide various slew and sample functions. The Smooth section will place a postitve and negative slew on input voltage transitions for lag effects, voltage controlled portamento and for low frequency filter applications.” In Cycle-mode (cycle jack patched to the input), the Smooth side “will oscillate yielding a voltage controlled traiangle wave LFO. A high level into the HOLD input will enable the Smooth Function to be used as a track-and-hold circuit with voltage controlled slew rate. The Stepped funtion can be used as a sample-and-hold with voltage controlled slew rate limiting. In Cycle mode, a pulse applied to the Sample input will generate complex staircase waveforms for control voltage applications and for use as audio signals. The Coupler is an internal comparator which compares the output levels of the Smooth and the Stepped Generators. This output is useful for generating complex control voltages or random voltages.
The Serge Random Source (RS) combines a Serge Random Voltage Generator (RVG, left column) and a Serge Noise Source (right column) in one module. As the name suggests, the Random Voltage Generator produces random voltages which vary in a smooth or in a step-wise manner. Random timing pulses are also available. The Noise Source (NOI) provides both white and pink noise waveforms. The S/H SRC generates a special (“noisy”) waveform as an ideal input for Sample & Hold functions to produce random voltages of equal probability (similar to a 1/F distribution function). In addition, the Noise Source features a random voltage output which can be stepped through random voltages by sending trigger pulses or using the pushbotton.
Some details of the Random*Source SSG + RS module:
The Random*Source SSG+RS module is available as a DIY (semi-)kit containing:
Available now - DIY set: € 320 - BACK IN STOCK!
The Serge Variable Slope filter (VCFS) and Variable Resonance filter (VCFQ) is an combination of the two famous and essential filters of the Serge system. The The VARIABLE Q VCF (VCFQ) is an excellent general-purpose VCF that provides simultaneous low-pass, high-pass, band-pass and notch (band-reject) outputs combined with unique flexibility. Its trigger in, LOW mode and self osciallation allow a variety of uses from Oscillator to VC processing. The Variable Slope filter (VCFS) allows the amount of filtering to be dynamically controlled as well, from barely perceptible filtering to highly resonant, sharp cut-offs. The VCFS has an unrivaled unique, organic characteristic. With the support of Serge Tcherepnin, the Random*Source version adds abjustable resonance - expanding the filter's character way beyond what's been possible with the original version.
Some details of the Random*Source Serge filters module:
The Random*Source DIY Kit contains:
Price: € 280 - AVAILABLE AGAIN! -
The Serge Dual Extended ADSR (ADSR) contains two complex envelope generators. Each ADSR uses not only the four segment envelope normally encountered in synthesizers, but is designed with extra features such as an initial voltage controllable delay time, voltage control of each segment, switchable slope forms, and a master voltage control. Each segment may be manually set and voltage controlled. In addition to the normal Attach, Decay, Sustain, and Release segments, an Initial Delay time is included. A master 1V/OCT inout allows to control all slope times for effects such as decreasing the entire envelope time as the pitch of an associated oscillator increases - a phenomenon is typical of many acoustic instruments.
Some details of the Random*Source ExtADSR module:
The Random*Source ADSR module is available either as a DIY kit or as full module:
Status: OUT OF STOCK
Divide & Compare provides a number of mathematical and logical functions for all sorts of rhythmic effects. The module combines a Serge Divide by N Comparator with a Pulse Divider and Boolean Logic.
The Serge ÷N COM is a sought-after and essential Serge module (1" wide) covering a number of functions: comparator, voltage-controlled pulse divider, and voltage-controlled staircase generator.
As the name suggests, the Pulse Divider takes a pulse train in and provides multiple simultaneous divided outputs, including odd-numbered divisors like 5 or 7 - great for creating polyrythms. The module can be jumpered so that the top input of the Inverter in the Boolean Logic section (also) acts as a RESET input. Boolean Logic offers two inverters as well as OR, AND, and XOR (exclusive or) gates and is ideal combine triggers in various ways. Like the Pulse Divider, it can be used in the audio range, too. offering two inverters, and OR, AND, and XOR gates.
For those interested in history, the Pulse Divider is based on a core design by Ken Stone - many thanks to Ken! Pulse Divider and Boolean Logic have been part of many Serge Systems even though they are not not original Serge designs. Divide & Compare is a great companion for the Sequencer 8.
4x4 module: € 595 AVAILABLE (may take 5-10 days)*** This is 4U format - not eurorack! ***
Some Random*Source pcbs for Serge modules are available here. These boards are not recommended for beginners, some prior soldering and assembly experience is highly recommended. Please not that these pcbs are for 4U format (6" long).
The Serge NTO, Serge's legendary oscillator featuring variable wave outputs and much more, is now available as a SMT pcb set with all SMT parts already reflow soldered in.
The Random*Source pcb kit contains (only!):
Price: € 260 - LIMITED STOCK
The Variable Slope filter (VCFS) was nearly impossible to get over decades. It allows the amount of filtering to be dynamically controlled, from barely perceptible filtering to highly resonant, sharp cut-offs. The VCFS has an unrivaled unique, organic characteristic. The R*S version has a new Q knob and has been optimized for a wider sonic range. The through-hole version can be ordered here.
The Random*Source pcb kit contains (only!):
Price: € 70 - PCBs only - no parts included!
The Serge ÷N COM is a sought-after and essential Serge module (1" wide) covering a number of functions: comparator, voltage-controlled pulse divider, and voltage-controlled staircase generator. The Random*Source version of the Serge ÷N COM consists of a main pcb and a matching component pcb serving as an interface to the front panel.
The Random*Source pcb kit contains (only!):
Price: € 75 - NEW SMT VERSION including all SMT parts!