CEM3340

The CEM 3340 is a self contained VCO, originally produced by Curtis Electromusic Specialties. With both exponential and linear control inputs and up to four output waveforms: triangle, sawtooth, square, and pulse with voltage controllable pulse width. It has full temperature compensation making it extremely stable. Also included is provision for hard and soft synchronization of the frequency, and an output for easy adjustment of high frequency tracking.

In 2016 after twenty or more years of diminishing availabilty, in response to Coolaudio's V3340 re-design of the part to the same specifications, OnChip Systems remanufactured the 3340.

Projects
The Digisound 80-2 and 80-3 are well designed and versatile analogue VCO and VCLFO. To prevent the IC being put under too much stress if/when the outputs are shorted, all outputs should have a series 1K resistor. The triangle wave output is unbuffered and should never be used to drive an output directly, add a J201 FET follower to buffer it. A better sine output can be achieved by using instead the Thomas Henry VCO-1 waveshaper.

Projects

 * Digisound 80-2 VCO, 1980
 * Digisound 80-3 VCLFO, 1980
 * Build a Precision Controller Clock by Thomas Henry, Electronotes, May/June 1984, Special Issue E, pp. 11-17.
 * Low-Frequency VCO Gives Exponential Response by Thomas Henry, Electronics, January 13, 1983, pp. 168-169.
 * VCO Deluxe by Thomas Henry, Polyphony, Nov/Dec 1981
 * The VCO Maximus by Thomas Henry, 2017
 * andrewF CEM3340 VCO, Muff Wiggler forum, Oct. 2016, for Eurorack
 * Datasette OPECEM3340 – v3 (True Zero) on its way soon – Morph delayed, Muff Wiggler forum, Nov. 2016 and on Github, for Eurorack
 * TimoRozendal &#x0005B;pcb+panel&#x0005D; CEM3340 VCO for eurorack (8hp), Muff Wiggler forum, Oct. 2016
 * Hyperflange + Chorus by Craig Anderton, Modern Recording & Music, Jul/Sep 1983