A 4-pole

**voltage controlled filter** from

*Curtis ElectroMusic Specialities*.

**Features:**
from the original data sheet
low cost
voltage controllable frequency: 12 octave range minimum
voltage controllable resonance: from zero to oscillation
accurate exponential frequency scale
accurate linear frequency scale
low control voltage feedthrough: -45dB typical
filter configurable into low-pass, high-pass, all-pass, etc.
large output: 12V,P,P. typical
low noise: -86dB typical
low distortion in passband: 0.1% typical
long warm up drift
configurable into *low distortion voltage controlled sine wave oscillator*
±15 volt supplies

**Synthesizers using the chip:**

with the amount used

CMI Fairlight II (earlier versions) 8
Crumar Trilogy 6
Elka Synthex 8
Linndrum 2
Oberheim OB-8 16
Oberheim OB-SX ?
Oberheim OB-Xa ?
PAiA Proteus 1
PPG Wave 2.0 4
Sequential Circuits Prophet-5 rev.3 5
Sequential Circuits Prophet-10 10
Sequential Circuits Pro-One 1