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.[1]
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.[2][3][4]
Projects
The Digisound 80-2 and 80-3 are well designed and versatile analogue VCO and VCLFO.[5][6] 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.[7] A better sine output can be achieved by using instead the Thomas Henry VCO-1 waveshaper.[8][9]
References
- ^ CEM3340 data sheet at CEM3374.com
- ^ Curtis Electromusic Specialties, Facebook, 5 June 2016
- ^ Curtis Family Speaks Out Against Behringer Synth Clone Plans Using CEM3340 by Rounik Sethi, Ask.Audio, 21 Mar 2017
- ^ CEM3320/V3320, SDIY list, Sep 2017
- ^ Digisound 80, Modular Synthesizer (Retro), SOS Jan 2000 by Paul Nagle
- ^ 80-2 Voltage Controlled Oscillator
- ^ Does the A SOL MC-202 modular kit work on the SH-101?, Muff Wiggler forum, Nov 2010
- ^ The VCO-1 Project
- ^ VCO/LFO PCB for CEM3340 chips, Muff Wiggler forum, Aug 2015
External links
- The VCO-555 by Thomas Henry an approximation of the CEM3340
- CEM 3340 data sheet
- Picture of de-encapsulated defect CEM 3340 at Stromeko Synth World
- Dual VCO (CEM3340-based, with thru-zero FM and various types of sync) by Juergen Haible
- Things to come: CEM3340 VCO, nonlinearcircuits, 17 August 2016
- CEM3340 VCO (Voltage Controlled Oscillator) designs by Tom Wiltshire, 27 August 2016
- ICs for Electro-Music (Part 1) by Charles Blakey
- A look at the VCO's of some famous analog synthesizers. by Chris Meyer, The Secret Life of Synthesizers, 25 Oct 2016
Projects
- Digisound 80-2 VCO, 1980
- Digisound 80-3 VCLFO, 1980
- VCO Deluxe by Thomas Henry, Polyphony, Nov/Dec 1981
- Low-Frequency VCO Gives Exponential Response by Thomas Henry, Electronics, January 13, 1983, pp. 168-169.
- Hyperflange + Chorus by Craig Anderton, Modern Recording & Music, Jul/Sep 1983
- Build a Precision Controller Clock by Thomas Henry, Electronotes, May/June 1984, Special Issue E, pp. 11-17.
- andrewF CEM3340 VCO, Muff Wiggler forum, Oct. 2016, for Eurorack
- TimoRozendal [pcb+panel] CEM3340 VCO for eurorack (8hp), Muff Wiggler forum, Oct. 2016
- Datasette OPECEM3340 – v3 (True Zero) on its way soon – Morph delayed, Muff Wiggler forum, Nov. 2016 and on Github, for Eurorack
- The VCO Maximus by Thomas Henry, 2017