This VCO is build on the legendary 3340 IC which has been used in many classic synthesizers such as the Roland SH-101 and the Sequential Prophet 5 amongst others. Recently production of the IC started up again, so that classic analog sound is available again.
The Oscillator One is build to leverage all functionality this IC has to offer, and then some. The Saw shift adds a second saw wave that can be phase shifted to the original one, as if that’s not enough, a third saw wave can also be added to further spice up the sound. A Linear Ramp waveform has also been added and provides something that has the heart of a square wave but the soul of a saw wave. In total 7 waveforms are outputted simultaneously and offer a wide variety of timbres.
- 1V per Octave tracking
- Covers the whole audio spectrum (from 16Hz to 20kHz )
- Shifted Saw
- Linear Ramp
- Linear as well as exponential FM capabilities, accessible simultaneously.
- Octave select switch.
- Coarse (+/- 1 Oct) and fine (+/- 1 semitone) pitch tuning.
- Pulse Width modulation input.
- Soft and Hard Oscillator sync.
- Saw-shift modulation with 2 or 3 saw-waves.
- Expansion port
- Easily repairable. Through-hole components, socketed IC’s and publicly available schematics make repairs possible by any skilled technician if ever the need arises.
Links and documentation
- Board A Build Guide
- Board B Build Guide
- VCO-1 Bill of Materials (BOM)
- Calibration guide
- AS3340 datasheet