The VCS3 (from Voltage Control for Studio with 3 components) is a 3-oscillation effects musical analog synthesiser, initially produced in 1969 by EMS. It was nicknamed 'The Putney'. The VCS3 was smaller and less cumbersome than the Moog Taurus and similar early synthesizers. It was also briefly known as the 'Synthi A' (a version housed in a plastic briefcase) and the 'Synthi Keyboard 1' (with attached keyboard). The EMS Synthi and VCS3 were used on many classic rock records.
VCS3s are used in music for reverb and special effects. The VCS3 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 two stereo output amplifiers. The VCS3 was a semi-modular analog synthesizer; that is, it had patchable routing using a small matrix panel. The player would insert metal pins in this panel and connect sections of the synthesizer together. With careful design, a creative synthesist could make incredibly complex sounds from only a few components. At the bottom of the unit, the joystick allows the player to control several parameters simultaneously.
The VCS3, in spite of the fact that it is a very basic 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 used by the BBC Radiophonic Worshop on the Doctor Who television soundtrack during the 1970s. It 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), King Crimson, The Alan Parsons Project, and Todd Rundgren, among many others. A well-known example of its use is on Pink Floyd's Dark Side of the Moon (1973), where it was used extensively, to create a multitude of effects, most noticibly with the ticking clock, and with the pulsating bass on 'On the Run'.
John Paul Jones used the VCS3 on a number of Led Zeppelin songs to create various sonic effects. These include 'The Rain Song' (overdubs), 'No Quarter', and 'The Crunge' from Houses of the Holy; 'In the Light' from Physical Graffiti; Overdubbed sounds on 'Four Sticks' and 'Achilles Last Stand', and the bridge between 'Friends' to 'Celebration Day' on Led Zeppelin III. Commenting in Keyboard magazine, Jones liked the VCS3, and used it often, although he said it was 'murder to keep in tune' and 'wasn't sophisticated enough to sound like a synthesizer', which is exactly what he liked.