A voltage controlled oscillator integrated circuit from SSM. It provided pulse (with pulse width modulation), sawtooth, and triangle outputs (the triangle required a bit of supporting circuitry). Both soft and hard sync / reset inputs were provided, and there was a provision to add an external trimmer to implement high frequency compensation for accurate scaling up to 10 KHz. It accepted a V/octave input with an internal exponential converter circuit.
Two variants were available. The 2033 implemented an internal heater for the exponential converter, keeping it at a constant high temperature so that the IC would not require the designer to add an external tempco. The 2031 was a simplified (and smaller) version, with only square wave outputs that were compatible with "TTL" voltage levels. It was intended for voltage-controlled clocking and logic applications, such as clocking a sequencer or drum machine.
The 2030's most notable uses were as the VCOs in the Rev 1 and 2 Prophet-5, and the Voyetra 8. The 2033 was used in the Mono/Poly.