Solid State Micro Technology for Music

Usually referred to by the the acronym SSM which can mean Solid State Micro Technolgy for Music, Solid State Music Technology or Solid State Microelectronics depending on which documentation one looks at.

The company
Founded in 1975 by John Robert Burgoon, Solid State Music Technology (SSM) originated out the Homebrew Computer Club, an early 1970s Silicon Valley computer hobbyist group. It was one of two companies that in the mid-1970s designed and sold analog integrated circuits used in synthesizers, the other was Curtis Electromusic Specialties.

SSMs first products were computer boards for the now-obsolete S-100 bus standard, including some boards intended for music applications. As Dave Rossum told the story in a 1981 interview with Polyphony magazine, an engineer named Ron Dow had come to E-mu Systems looking for funding to develop a voltage controlled amplifier on a chip. However, the proposed design would not have been compatible with the modular synthesizers that E-mu was selling at the time, so they turned Dow down. Dow then went to SSM and they agreed to fund the project and market it. The result was the first synthesizer-specific integrated circuit, the SSM2000 VCA. The following year, Dow came back with an idea for an improved design that was compatible with E-mu's systems and E-mu became involved with SSM in the design, the result was the SSM2010.

E-mu became both a co-creator and a customer for SSMs circuits, incorporating the ICs into their modulars; Rossum consulted with Dow and SSM on the designs. Shortly after, E-mu consulted with Oberheim on their first non-SEM polyphonic synth designs using the SSM ICs. SSM chips were used in many late-1970s and early-1980s polyphonic analog synths, including the Oberheim models of the day, the Voyetra 8, and the rev 1 and 2 Prophet-5s. Connoisseurs of such things consider the SSM chips to produce a "thicker" and "ballsier" sound than the Curtis design, but the SSMs had some reliability problems and by 1985 most designers that were still specifying these types of ICs had switched to Curtis.

SSM was bought out by PMI, which in turn was acquired by Analog Devices, the current owner. Most of the classic SSM synth-specific designs are long out of production, but AD does still produce some of the VCA circuits and matched transistor arrays.

Equivalents
Functionally equivalent ICs have been produced by Alfa Rpar AS, Coolaudio International Ltd. and Sound Semiconductor Inc.

SSM ICs

 * SSM2000 – Dual linear-antilog voltage controlled amplifier (VCA)
 * SSM2010 – VCA
 * SSM2011 – Audio preamplifier system
 * SSM2012 – VCA
 * SSM2013 – VCA
 * SSM2014 – Operational voltage controlled element
 * SSM2015 – Microphone preamplifier
 * SSM2020 – Monolithic /log/antilog amplifier, also as XR5101
 * SSM2022 – Dual linear-antilog VCA
 * SSM2024 – Quad current controlled amplifier (quad VCA)
 * SSM2030 – Voltage controlled oscillator (VCO)
 * SSM2031 – High frequency oscillator/voltage to frequency converter
 * SSM2033 – VCO
 * SSM2036 – VCO
 * SSM2038 – VCO
 * SSM2040 – Voltage controlled filter (VCF), also as XR5099
 * SSM2044 – four pole voltage controlled filter
 * SSM2045 – Music Voicing System (2-Pole and 4-Pole Low Pass VCF and Mixer/VCA)
 * SSM2047 – Music voicing system
 * SSM2050 – Voltage controlled transient generator
 * SSM2055 – Voltage controlled transient generator
 * SSM2056 – Voltage controlled transient generator
 * SSM2060 – Digitally controlled voice
 * SSM2110 – Audio level detection system
 * SSM2164 – Low Cost Quad Voltage Controlled Amplifier
 * SSM2300 – 8 channel multiplexed sample and hold

Prebuilt

 * Akai VX600	- 9 SSM2300
 * Buchla 296e – 8 SSM2020
 * Crumar Bit One – 6 SSM2044 in early models
 * Crumar Performer B – SSM2040, SSM2050
 * Stratus – 1 SSM2020, 1 SSM2055
 * Crumar Trilogy – 1 SSM2020
 * Division 6 Filtare SEIII -
 * Doepfer A-105 24db SSM Low Pass Filter - 1 SSM2044
 * E-mu Systems Drumulator – 2 SSM2044
 * E-mu Systems SP-12 – 2 SSM2044
 * E-mu Systems SP-1200 – 2 SSM2044
 * E-mu Systems Emulator – 4 SSM2044
 * E-mu Systems Emulator II – 8 SSM2045
 * E-mu Systems Emax – 4 SSM2300, 8 SSM2047
 * Ensoniq SDP-1 – 6 SSM2044
 * Ensoniq ESQ1 – 4 SSM2300
 * Ensoniq SQ-80 – 4 SSM2300
 * Fairlight CMI II – 8 SSM2045 in later versions
 * Hohner P120N - 2 SSM2044
 * Hohner PK250 - 2 SSM2024
 * Kawai/Teisco K3 & K3m – 6 SSM2044
 * Kawai/Teisco SX-210 – 8 SSM2044
 * Kawai/Teisco SX-240 – 8 SSM2044
 * Korg Monopoly – 4 SSM2033, 1 SSM2044
 * Korg Poly 61 – 6 SSM2056
 * Korg Poly 6 – 6 SSM2044, 6 SSM2056
 * Korg Trident – 9 SSM2044
 * Octave Plateau Voyetra 8 – 8 SSM2024, 8 SSM2044
 * Octave The Cat SRM – 1 SSM2040
 * PPG EVU – 8 SSM2044
 * PPG Wave 2.2 & 2.3 – 8 SSM2044
 * RSF Kobol Expander I – 1 SSM2040, 2 SSM2050
 * Sequential Circuits Prophet 5, Rev 1 & 2 – 10 SSM2020, 11 SSM2030, 5 SSM2040, 10 SSM2050
 * SIEL DK600 – 6 SSM2024, 2 SSM2031, 6 SSM2044, 6 SSM2056
 * SIEL DK-80 – 2 SSM2045
 * SIEL EX-80 – 1 SSM2045
 * SIEL Kiwi – 6 SSM2024, 2 SSM2031, 6 SSM2044, 6 SSM2056
 * SIEL Opera 6 – 6 SSM2024, 2 SSM2031, 6 SSM2044, 6 SSM2056
 * Simmons SDS5 – 1 SSM2044 per module
 * Simmons MTX9 – 1 SSM2300
 * Solton Programmer 24 - 1 SSM2044
 * Solton SM100 – 6 SSM2045, 12 SSM2056
 * Solton TS3 - 2 SSM2300
 * Solton TS4 - 2 SSM2300
 * SRM Synthesizer Octave Cat -
 * Steiner EVI – SSM2040?
 * Syntec Banana – 6 SSM2044
 * Voyetra 8 - 8 SSM2024, 8 SSM2044
 * Waldorf Wave – 16 SSM2024

DIY projects

 * Aries System 300 – 1 SSM2030 in the AR-338, 2 SSM2030 in the AR-341
 * Digisound 80-11 – 1 SSM2020
 * Digisound 80-7 – 1 SSM2040
 * Digisound 80-8 – 1 SSM2050
 * Fonitronik SSM2044 VCF - 1 SSM2044
 * Synthesis Technology MOTM 440 – 4 SSM2210, 5 SSM2220
 * Thomas Henry: A four-pole lowpass VCF – SSM2040
 * Thomas Henry: A one-chip ADSR – SSM2056
 * Timo Rozendal 2044 VCF

Data sheets
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Some are also freely available from:
 * MaxMidi Rare Silicon
 * Synfo.nl