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CEM and SSM chips are analog integrated circuits (commonly called "chips") used in many synthesizers.

Curtis Electromusic Specialties

Founded by Doug Curtis in 1979, CEM developed a family of signal processing products for electronic music synthesizers and audio equipment. In 1988, Doug migrated the company to become OnChip Systems. In 2016, it was announced that the CEM3340 VCO had been remanufactured by OnChip using the original design, the CEM3340 RevG. Other manufacturers manufactured copies of the Curtis Chips as well since the patents had expired. Cool Audio produces the V3340 and the V3320. AS ALFA RPAR released the AS3310, AS3320, AS3330, AS3340, AS3345 and AS3360 in DIP and SMD packages.


CEM3318 ADSR (microprocessor-controlled via two voltages)
CEM3320 24 dB/Oct. VC multimode filter
CEM3328 24 dB/Oct. VC LPF
CEM3330 exp/lin VCA
CEM3335 exp VCA
CEM3340 VCO (Saw,Tri,Pulse)
CEM3345 VCO (Saw,Tri,Pulse) with comparator
CEM3350 12 dB/oct Multimode Filter x2 (no notch)
CEM3360 VCA x2
CEM3371 Envelope x2
CEM3372 24 dB/oct. Filter, Mix, VCA
CEM3374 VCO x2 (PWMable Pulse, Tri, Saw)
CEM3378 24 dB/oct. VCF, 2-channel mixer, VCA
CEM3379 24 dB/oct. VCF, VCA, VC pan
CEM3381 / PDA381 VCA x2 linear
CEM3382 / PDA382 VCA x2 log
CEM3385 24 dB/oct Filter (LoFi)
CEM3387 signal processor 3-4 pole cascade Filter, VC Pan/VCA
CEM3389 signal processor 4 pole Filter, VC resonance, VCA, VC Pan
CEM3391 Microprocessor Controllable: VCF, VCA, Env (ADSR)
CEM3394 Microprocessor Controllable: VCO, VCF, VCA, external input (complete synth voice)
CEM3396 Microprocessor Controllable: Wave-Shaper x2, VCF, VCA
CEM3397 same core design as CEM3396 but with separate external signal (noise/sub/wavetable) input and VCA to mix stage and additional Pan VCA and L/R output stage. Originally labelled MS1215 and designed for Marion Systems MSR-2. Relabeled as PA397 for DSI.
CEM5508 / PD508 Octal Sample&Hold (8x)
CEM5530 30ch multiplex sample&hold (Prophet VS)

Solid State Music / Solid State Micro Technology for Music

Solid State Music, later known as Solid State Microtechnology for Music or simply "SSM," was founded by Ron Dow and John Burgoon in 1974, with assistance by Dave Rossum of E-MU Systems. The company originally produced synthesizer chip sets, and provided bare boards for the hobbyist to experiment with early SSM chips. In an unusual pairing, they also produced S-100 bus computer cards, including a Sound Synthesizer Card.[2] SSM was acquired by Precision Monolithics in 1988, who was in turn acquired by Analog Devices in 1990. New SSM-badged IC's continue to be introduced by Analog Devices, but bear little resemblance to the original SSM line. Several early members of the SSM team reformed in 2017 as Sound Semiconductor to develop audio IC's in the spirit of early SSM products.


SSM2000 Dual Linear-Antilog Voltage Controlled Amplifier SSM2013 Voltage Controlled Amplifier
SSM2014 Voltage Controlled Element
SSM2015 Microphone Preamplifier
SSM2020 Dual VCA
SSM2024 Quad VCA
SSM2030 Voltage Controlled Oscillator: Sawtooth, Triangle, Pulse (with PWM) and Soft Sync
SSM2031 High Frequency Oscillator/Voltage to Frequency Converter
SSM2033 Voltage Controlled Oscillator
SSM2038 Voltage Controlled Oscillator: Sawtooth, Triangle and Pulse (with PWM)
SSM2040 4-Section VCF (Exponentially controllable Cutoff over a 10,000 to 1 range, i.e. >13 octaves) SSM2044 4-Pole VCF
SSM2045 Music Voicing System : VCF (2-Pole and 4-Pole Low Pass) and Mixer/VCA
SSM2047 Music Voicing System
SSM2050 Voltage Controlled Transient Generator
SSM2056 Voltage Controlled ADSR type Envelope Generator
SSM2100 Monolithic Log/Antilog Amplifier
SSM2120/22 Dynamic Range Processor/Dual VCA
SSM2164 Low Cost Quad VCA (16 pins, intended to replace the SSM2024, although not a drop-in replacement) SSM2300 8-Channel Multiplexed Sample&Hold

List of synthesizers and which CEM/SSM ICs they use


AX80: 8x CEM3372 uP Signal Processor -CEM3372 Filter/Mix/VCA AX60: 6x CEM3394 uP Voice
AX73: 6x CEM3394 uP Voice
S-950: 8x 3387 (Marion Systems MS-9C upgrade only)

VX90: 6x CEM3394 uP Voice

VX600: 12x CEM3374B (IC1), 12x CEM3378 (IC5), 9x SSM2300 (IC 10-14 & IC 20-23) Aries System 300 modular

AR-338 oscillator: 1x SSM2030 AR-341 dual oscillator: 2x SSM2030 AR-344 dual envelope: 2x SSM2050


Banana created by Synthesizerstudio Bonn, since 1999 the SSB is closed..
Poly Synth: 12x CEM3310 EG, 12x CEM3340 VCO, 18x CEM3360 Dual VCA, 6x SSM2044 VCF


296 Programmable Spectral Processor: 8x SSM2020 VCA, 1x CEM3360 Dual VCA Cheetah

Cheetah MS6: 6x CEM3396 VC Waveshaper Crumar

Performer-2: SSM2040, SSM2050
Trilogy: 6x CEM3310 EG, 6x CEM3320 VCF, 6x CEM3330 Dual VCA, 1x SSM2020 VCA
Stratus: 6x CEM3310 EG, 6x CEM3320 VCF, 6x CEM3330 Dual VCA, 1x SSM2020 VCA, 1x SSM2055 Composer: 2x CEM3310 EG, 2x CEM3320 VCF, 2x CEM3330 Dual VCA
Spirit: 2x CEM3340 VCO, 2x CEM3350 Dual VCF, 3x CEM3360 Dual VCA
Bit ONE: 6x SSM2044 VCF Early Models, 6x CEM3328 VCF Late Models
Bit 01: 6x CEM3328 VCF
Bit 99: 6x CEM3328 VCF

Digisound-80 modular

80-2 VCO: CEM3340 VCO
80-3 VC LFO: CEM3340 VCO
80-4 VC Mixer: 3x CEM3330 dual VCAs
80-6 VCF: CEM3320 VCF
80-7 VC State Variable Filter: SSM2040 VCF
80-7A VC State Variable Filter: CEM3320 and CEM3335
80-8 Dual ADSR: 2x SSM2050 EGs
80-9 Dual VCA: CEM3330 dual VCA
80-10 Voltage Controlled Envelope Generator: CEM3310 EG
80-16 Dual Resonant Filter: CEM3350 dual VCF
80-18 Dual Multi-Function EG: 2x CEM3310 VCEGs
80-19 Dual VC LFO: CEM3374 and CEM3360
80-C9 Voice Card: 2x CEM3310 VCEGs, 2x CEM3340 VCOs, CEM3360 dual VCA, CEM3372 signal processor


A-105 24db SSM Low Pass Filter: SSM2044 A-106-6 XP Filter: CEM3379
A-107 Morph. Filter: CEM3379
A-109 VC Signal Processor: CEM3379 A-111-1 High End VCO: CEM3340

A-111-2 High End VCO II/A-111-3 Micro Precision VCO: CEM3340 A-111-4 Quad Precision VCO: CEM3340
A-111-5 Mini Synthesizer Voice: CEM3394
A-121 Multi Mode Filter/A122 LPFilter/A123 HPFilter: CEM3320 A-122 LPFilter: CEM3379 in later versions

A-130 VCA (linear)/A-131 VCA (exp.)/A-134 VC Panning: CEM3381 A-132-3 Dual Lin/Exp VCA: CEM3360 (early versions)
Dark Energy, Monophonic Synthesizer: CEM3394 (original model only)


Dynacord Add-one: 8x CEM3389


Drumulator: 2x SSM2044
SP-12: 2x SSM2044
SP-1200: 2x SSM2044
Emulator-I: 4x SSM2044
Emulator-II: 8x SSM2045 (24 dB/oct analog 4-pole low pass resonant filter (LPF)) Emax: 4x SSM2300 (Sample/Hold Mux), 8x SSM2047 (Filter/Amp)


Synthex: 8x CEM3320 VCF

EK-22: 6x CEM3396 VC Waveshaper


Mirage: 8x CEM3328 VCF
ESQ-1: 8x CEM3379 VC Signal Processor Filter/Mix/VCA, 1x CEM3360 Dual VCA, 4x SSM2300 SQ-80: 8x CEM3379 VC Signal Processor - Filter/Mix/VCA, 1x CEM3360 Dual VCA, 4x SSM2300 SDP-1: 10x CEM3328 VCF

Fairlight CMI II/IIx: 8x CEM3320 VCF in earlier versions, 8x SSM2045 VCF in later versions

Fender / Rhodes
Chroma: 8x CEM3350 Dual VCF, 8x CEM3360 Dual VCA

Polaris: 6x CEM3374 Dual VCO, 6x CEM3372 Filter/Mix/VCA Forat

Forat F9000: 4x CEM3320 VCF Hohner

P120N: 2x SSM2044
PK120/150: 1x CEM3391, 2x SSM2024 PK/MR250: 2x CEM3391, 2x SSM2024 L/D160: 2x CEM3391, 2x SSM2024


K3(m): 6x SSM2044 SX-210: 8x SSM2044 SX-240: 8x SSM2044


CTS-2000: 1x CEM5530 30ch S/H, 8x CEM3389 VC Signal Processor


Mono/Poly: 4x SSM2033 VCO, 1x SSM2044 VCF Polysix: 6x SSM2056 EG, 6x SSM2044 VCF Poly-61: 6x SSM2056 EG
Trident: 9x SSM2044 VCF


LinnDrum: 2x CEM3320 VCF, 1x CEM3360 Dual VCA

Linn 9000: 4x CEM3320 VCF


Memorymoog: 19x CEM3340 VCO, 26x CEM3360 Dual VCA, 12x CEM3310 EG


OB-8 & OB-Xa: 2x CEM3330 VCA (Some OB-Xa models), 2x CEM3360 Dual VCA, 16x CEM3340 VCO, 16x CEM3310 EG, OB-Xa 16x CEM3320 VCF, OB-8 8x CEM3320 VCF
OB-X: 16x CEM3310 EG (2 per voice)
OB-SX: 2x CEM3340 VCO, 1x CEM3320 VCF, 2x CEM3310 EG per voice

Matrix-6 & Matrix-6R: 6x CEM3396
Matrix-1000: 6x CEM3396 (narrow version)
Matrix-12: 12 x CEM3374 Dual VCO, 12 x CEM3372 Filter/Mix/VCA Xpander: 6x CEM3374 Dual VCO, 6x CEM3372 Filter/Mix/VCA
OB-1 (same as OBI or OB-I): 2x CEM3310 EG
Prommer: 1x CEM3328 VCF
DPX-1: 1x SSM2013 VCA, 8x SSM2045 VCF, 5x SSM2300
DX: 1x CEM3320 VCF - "Toms" Voice
DMX: 4x CEM3320 VCF - "Conga", "Timbale", "Toms", "Noise" Voices Stretch-DX: 3x CEM3328 VCF LPF

Octave Plateau

The Cat SRM: 1X SSM2040 VCF

Voyetra-8: 8X SSM2024 VCA, 8X SSM2044 VCF, 16X CEM3340 VCO PAiA

Proteus: 2x CEM3340 VCO, 1x CEM3320 VCF, 1x CEM3310 EG, 1x CEM3330 Dual VCA

9601 Stereo Compressor: 1x SSM2120 PPG

Wave 2.2 / 2.3: 8x SSM2044 VCF, 4x CEM3360 VCA Wave 2: 8x CEM3320 VCF, 8x CEM3310 EG


SH-101 and MC-202: 1x CEM3340 VCO
MKS-20: 5x CEM3360 Dual VCA
Jupiter-6: 12x CEM3340 VCO, 6x IR3109 VCF, 6x CEM3360 Dual VCA
MKS-80 (to serial #511799/early models): 16x CEM3340 VCO, 8x IR3109 VCF, 8x CEM3360 Dual VCA (4 for X-Mod)
MKS-80 (serial #511800 and higher/later models): 16x IR3R03 VCO, 8x IR3R05 VCF/VCA, 4x CEM3360 Dual VCA (for X-Mod)

Kobol Expander I: 2x SSM2050 EG, 1x SSM2040 VCF

Sequential Circuits / Dave Smith Instruments Evolver series: Curtis for Filters

Prophet-5: the first Prophet 5 series used the SSM filter; later they were changed to CEM

Prophet-5 Rev 1 & 2: 11x SSM2030 VCO, 5x SSM2040 VCF, 10x SSM2050 EG, 21x SSM2020 VCA
Prophet-5 Rev 3: 11x CEM3340 VCO, 10x CEM3310 EG, 5x CEM3320 VCF, 14x CA3280 VCA
Prophet-5 Rev 4: CEM3320, CEM3340, SSI2140
Prophet-10: 22x CEM3340 VCO, 20x CEM3310 EG, 10x CEM3320 VCF
Prophet 600: 12x CEM3340 VCO, 6x CEM3372 VCF/VCA, 4x CEM3360 Dual VCA
Pro-One: 3x CEM3340 VCO, 2x CEM3310 EG, 1x CEM3320 VCF
Prophet T8: 16x CEM3340 VCO, 8x CEM3372 Signal Processor - CEM3372 Filter/Mix/VCA
Six-Trax: 6x CEM3394 uP Voice
Multi-Trak: 6x CEM3394 uP Voice
MAX: 6x CEM3394 uP Voice
Split8: 8x CEM3394 uP Voice
Prophet VS: 4x CEM5510 Fast Sample/Hold, 2x CEM5530 30ch S/H, 8x CEM3379/CEM3389 VC Signal Processor, 2x CEM3365 Dual DAC Multiplier, 1x CEM3360 VCA
Prophet 2000: 8x CEM3379 VC Signal Processor
Prophet 3000: CEM3387
Studio 440: 8x CEM3389 VC Signal Processor, 1x CEM3360 Dual VCA, 1x CEM5530 30ch Sample/Hold
Drumtraks: 2x CEM3320


DK600: 2x SSM2031 VCO, 6x SSM2024 VCA, 6x SSM2056, 6x SSM2044 VCF DK-80: 2x SSM2045 VCF
EX-80: 1x SSM2045 VCF
Opera 6: 2x SSM2031 VCO, 6x SSM2024 VCA, 6x SSM2056, 6x SSM2044 VCF Kiwi: 2x SSM2031 VCO, 6x SSM2024 VCA, 6x SSM2056, 6x SSM2044 VCF

Simmons Drums

MTX9: 1x SSM2300
SDS9/SDS1000: 3x CEM3394 VC Synth, 1x CEM3372 (SDS9) SDS8: 5x CEM3372 VC
SDS7: CEM3340 - 1x per module; CEM3372 - 1x per module SDS5: SSM2044 - 1x per module
SDS200: 2x CEM3394
SDS400/SDS800: 4x CEM3394


TS3: 3x CEM 3360, 2x SSM 2300
TS4: 1x CEM 3360, 2x SSM 2300
SM100 analogue synthesizer (6 voices): Each voice uses 2x SSM2056 (ADSR) and 1x SSM2045 (VCA+VCF) Programmer 24: 1x CEM3350 12 dB Dual VCF & 1x SSM2044 24 dB VCF

Steiner Parker

EVI: 1x CEM3340 VCO, 1x SSM2040 VCF


SX-500: 1x SSM2045 (this synth module is a clone of the SIEL EX-80) Synton

Syrinx: 2x CEM3310 EG, 2x CEM3340 VCO, 2x CEM3350 Dual VCF, 1x CEM3360 Dual VCA Waldorf

Wave: 16x CEM PD508 Multiplexer/S&H, 16x CEM 3387 VCA/VCF, 1x Quad VCA SSM2024 for 4 voices.

Microwave1: 8x CEM3389 VCF,VCA,VCP in Rev A, 8x CEM3387 VCF,VCA,VCP in Rev B Wersi

Spectra-DX series : 1x SSM2045