Serge Modular Music Systems Kits and Systems

Most musicians could not afford the Moogs, Arps, or Buchla�s that were the high end synthesizers of the 70s. Serge developed kits that they could assemble themselves, like the popular Heathkit Hi-Fi and Instrumentation kits of the day. In some cases, a person putting together an instrument would come to the factory and assemble and test the PC boards for the modules themselves.

This kind of do-it-yourself kit evolved into the panel system that�s described in the Series 79 brochure, with a beautiful detailed drawing of the open panel by Gary Chang shown here that was used in brochures and manuals.

Panels

The Serge "panel" was a 17" by 7" pre-drilled aluminum panel that could accommodate 16" of modules. In the early systems, the panel graphics were user-designed and resulted in some really wild looking systems. Rich Gold, among others, worked with Serge to come up with some geometric symbols to represent various input/output functions for the modules. This resulted in some very cryptic panel graphics. Later, things were mostly labeled with the functional names, but outputs were always surrounded with a rectangular border.

Early systems had paper graphics over the panels that were lacquered. A better technique used standard adhesive-backed paper graphic with a Mylar overlay, which could be easily applied by the assembler.

Serge located a photographic process that could expose the panel graphics on a photo-screened thin aluminum sheet. Individual module faceplates could be made this way. Paul Young found that he could lay out an entire panel on one sheet, and the Series 79 and many custom panels were laid out using this method. Here is a photo of one six-panel machine with reversed faceplate graphics, silver lettering on a black background.

During this time, largely due to Paul Young, exotic wood end panels were used to customize the look of the Serge system for particular artists.

Power Supplies

The power supplies were off-the-shelf units supplying plus/minus 12 volts, with a regulator attached to provide +6 volts for some of the earlier generation modules.

Patch Cords

The patch cords were banana plugs though out. This differs from the Buchla system, which used banana connectors for control signals and mini-phone connectors for audio signals. Jill Fraser�s hand applies a patch to the photo in the black-and-white Series 79 brochure photo above. Although the banana jacks on the panels were color-coded as to general functionality (red=trigger or logic, blue=control, black=audio, yellow or green = special), you could connect an audio output to a control input and vice-versa.

Unlike the Buchla or Moog design, Serge did not necessarily distinguish audio from control signals. As a result, a component like a "Slew Generator" could be used as an envelope generator, a vibrato source, an oscillator, or a modulator. This ability to configure modules to perform various functions was a unique and powerful feature of the Serge system and allowed some wildly diverse sound synthesis techniques.

The kits contained individual modules, which included:

• Assembled and tested PC board
• Banana jacks
• Potentiometers
• Switches
• Other connectors
• Resistors attached to front panel components
• Hook up wire to connect the panel components to the PC boards

The modules were assembled on a rack to be mounted behind the front panel. The panel assembly consisted of:

• Panel
• Panel graphics
• Rails to hold the set of PC boards behind the panel
• Standoffs to mount the PC board/rail assembly behind the panel
• Power supply wire and connector to interconnect PC boards to power supply

Case

There was no standard case for Serge synthesizers. The early panels were housed in aluminum chassis boxes and used just like that, or the owners would build custom cases --often simple frames. There were quite a few wooden frames made to house 3, 4, 6, or 8 panels. Some systems were built into Zero-Haliburton anodyzed aluminum instrumentation cases (see photo). Chas Smith made a number of very nice welded metal cases, including a large black anodyzed system for Kevin Braheny, which was dubbed the "death star." Eventually, a template was made for a side panel that could be used for 3 or 4 panels. This L shaped template was the eventual design for the Series 79 wood case: two wood panels that mount on the sides of 4 chassis boxes. This is evident on the black faced system above.

Systems

With colleges and universities adopting Serge systems, we came up with standard system packages, notably the Series 79. This was only a suggested system, however, and many choose to design their own custom panel of modules. Eventually the Series �79 was discontinued (it was just a suggestion), but when it was popular, we usually had at least one system in stock and a person or institution could order a Series �79 synthesizer and get immediate delivery.

There were probably a few Serge systems that were used with black and white keyboards, but we never made one for the system. Serge had developed a touch panel technology, and he invented a flexible 16 pad pressure sensitive keyboard/sequencer that fit into one panel. It was quite popular, but many people used controllers other than keyboards, including pitch-to-voltage converters that could be used with various acoustic instruments.

Part of the exciting thing about the Serge system was that you could set up a complex rhythm with transforming timbral shapes as an automated patch, something like a drum machine with dynamic tonal parameters, then adjust settings slightly or change things with a switch that would radically alter the rhythm and sound. Sources of random voltage combined with modules set up as pulse dividers could make some quite sophisticated rhythm tracks. Control voltages could be fed back into control inputs to change linear slope generators to exponential. The interaction with the instrument was very different from a traditional keyboard approach to a synthesizer, and the sounds and music resulting from this interaction were different than music you�d hear on a Moog or keyboard synthesizer. The closest similarity was with the Buchla instrument, but the sounds were immediately dissimilar. The dynamic range of the Serge modules was very wide, and the timbre was bright. Plus, since a control voltage could tranmogrify into an audio signal in a Serge patch, sounds and patches produced rhythms, timbers, and aleatoric sequences that were impossible on other machines.

Serge was always improving the quality and uniqueness of the instrument. He designed filters with different slopes, voltage-controlled resonance, even one that had a voltage controlled cutoff slope. He also had invented modules like the Wave Multipliers which radically transformed simple waveforms into vary rich timbrally modulated tones �very different from a Ring Modulator. The resonant EQ, phaser, the waveshaper and the waveshaping capabilities of the New Timbral Oscillator could produce complex sounds that seemed vocal and dreamlike --or rich, brassy or metallic.

It was a multi-dimensional system, not designed solely for the keyboard artist. The control modules were probably the most unique of all. The "slew" module provided accurate parametric control of pitch, timbre, and timing. It combined into one module the capabilities that were used as portamento and envelope generation in traditional synthesizer systems but were extended by Serge to filtering, pulse division/delay, and other sub-audio and audio functions. The Analog Shift Register, Divide-By-N comparator, Quantizer, Smooth and Stepped Function Generator, Sequencers, Random Voltage Generators, and Slope Generators yielded analog programming control over seemingly infinite timbral landscapes.

For those interested in both technology and music in the 70s and 80s, the Serge system allowed music to be composed, recorded, and performed with op-amps, logic ICs, discrete transistors, capacitors and resistors. Patch cords, switches and knobs were real-time controllers, along with widely diverse types of transducers. This proceeded the current era in which mass-production digital logic finally became affordable for the musician. Digital technology ultimately dominated electronic music instrument design, both in sound production techniques and instrument/computer control.

Yet Serge Tcherepnin�s designs and products remain viable and sought-after instruments today. If you are lucky enough to have access to a Serge Modular Music System, you�ve got artistic possibilities that are barely framed with limitations like decibels and microtones. Structure, timbre, composition elements are exposed �all of sound and music is interactive, intertwined and made interdependent by a complex arrangement of reconfigurable elements.

October 2001

Darrel Johansen