Module description

A Voltage Controlled Oscillator based on the CEM 3340 chip.

Exponential response of 1V/octave. Fully temperature compensated. Very accurate in the range 5Hz to 10kHz (suitable for polyphonic use) but will operate over a range of 0.1Hz to 50kHz. Six outputs available simultaneously : 0-10V sawtooth, pulse, sine and triangle together with ±5V sine and triangle waves. Linear and exponential frequency modulation. Voltage and manual control of pulse width from 0 to 100%. Three synchronisation techniques may be used at the same time: hard negative, hard positive and soft.

Construction information

• ETI February 1980 (3.5MB pdf file)
  Note: the original ETI article covers both the 80-2 VCO and the 80-3 VCLFO
• Digisound document (1.8MB pdf file)
• PCB foil diagram (46KB gif file)
• PCB size (mm) 160 x 82

Front panel designs

• Original 9 x 3 inch (3KB fpd file)
• MOTM-format 5U x 2U (3KB fpd file)

For more Digisound-related documents, please refer to the Other Digisound documents page.