The VCS 3 (from Voltage Control for Studio with 3 components) is an oscillation effects musical analogsynthesiser, initially made in 1969 by EMS. The VCS 3 was smaller and less cumbersome than the Moog Taurus and similar early synthesizers. It was also known as the Synthi A (a version housed in a plastic briefcase) and the Synthi Keyboard 1.
VCS 3s are used in music for reverb and special effects. A well-known example of its use is on Pink Floyd's Dark Side of the Moon, where it was used extensively, to create a multitude of effects, most noticeably with the ticking clock, and with the bass on "On the Run". The VCS 3 has a Noise Generator, two Input Amplifiers, a Ring Modulator, a Voltage Controlled Low Pass Filter (VCF), a Trapezoid Envelope Generator, Joy-Stick Controller, Voltage Controlled Spring Reverb unit and 2 Stereo Output Amplifiers. This synth was also used by Brian Eno when he was with the band Roxy Music.
The VCS 3 was quite popular among the progressive rock bands of the day and was used on recordings by Yes, Brian Eno (when he was with Roxy Music), The Who, and Todd Rundgren, among many others. However, it is most widely known for its use on the immensely popular Dark Side of the Moon album. The VCS 3, in spite of the fact that it is a monophonic synthesizer, underwent something of a renaissance in the late 1990s and early 2000s, with bands who looked to include a more retro synthesizer sound in their music.
The VCS3 was a standalone instrument; a keyboard was available but was not an integral part of the instrument and often seemed to get in the way of creative patching.
Perhaps because of its keybapord unfriendliness the VCS3 has sometimes been dismissed as a sound effects or weird noise generator and even by Wendy Carlos as a toy, which misses the point that electronic music was never meant to be about interval and key and all that other well tempered nonsense.
The matrix patch bay of the VCS3 make this an instrument for electronic composition, the patchbay is in effect the keyboard and a complex patch the score, the time variable being supplied by the rising and falling of the oscillators and envelope signals.