The Prophet VS is a synthesizer released in 1986 by Dave Smith’s Sequential Circuits. The Prophet VS introduced Vector Synthesis - two dimensional crossfading between waveforms.

Sequential folded shortly after the VS was introduced, but many of the ideas from the VS lived on in the Korg Wavestation. 

The video above, via Retrosound, demos some typical VS sounds. 

Features:

• 8-voice polyphony
• Multi-timbral (2 part)
• 96 preset waveforms + 32 user waveforms
• Two LFOs, each with own envelope generator
• Curtis analog (digitally controlled) 4-pole lowpass filter, with dedicated envelope generators
• 5 stage amp, filter and mix envelopes
• 61 note keyboarded with velocity & aftertouch
• 100 patch memory
• Twin chorus, stereo effects, panning of individual oscillators/individual voices
• Arpeggiator

Resources:

• Unofficial Prophet VS page
• VS info at Wine Country
• Info at Vintage Synth Explorer
• Prophet VS clone project
• Prophet VS Yahoo Group