The CS-80V is really two single oscillator synthesizers in one box, with an additional Sub Oscillator, Ring Modulator and Arpeggiator. It also features a Tremolo/Chorus effect and stereo Delay line.
CS80V in full effect
The two lines of synthesis each feature an oscillator which can generate either a square, triangle, saw or sine signal which is then modulated by a midi syncable LFO and fed through a VCF using two filters in series, one high pass and one low pass each with its own frequency and resonance controls. These filters can be switched between 12db and 24db per octave and independently turned on or off to free up processor power.
The filters are modulated by one ADR envelope, which also has an initial level function that alters the envelope relative to the filter frequency.
Next the VCF output is fed into a VCA and mixed with the initial signal before passing through a standard ADSR envelope and finally an overall level control.
Four faders at the end of each line allow velocity and pressure sensitive control of the filter frequency.
The output of the two lines can then be balanced and a master brilliance and resonance control adjusts the filters of both VCFs together.
Each oscillator can be transposed down one octave or up a fifth, an octave, an octave and a fifth or two octaves. This is unusual on a synth and bears more resemblance to the organs from which the CS-80 descended.
A couple of handy features are an oscillator Sync button which allows the frequency of the second oscillator to be heard whilst the just first adds harmonics, a Link switch which bypasses the VCF and VCA for the second oscillator and feeds its signal through the VCF and VCA of the first oscillator, and the ever present detune to alter the pitch of oscillator two against oscillator one.
The Sub oscillator affects the mixed signal and has controls for speed and amount of effect on both VCOs, VCFs and VCAs.
Finally the Ring modulator has settings for attack, decay, speed, depth and overall mix. This adds some great harmonics and can either be a subtle enhancer or extreme destroyer of sounds.
There is an interesting bank of 24 switches in the middle of the synth, which access the original presets for the two synthesis lines. When working with a preset that you almost like this is a great way to quickly alter one or other of the sounds as it changes not only the oscillator, but the VCF and VCA as well.