The EMS Synthi A is a synthesizer which uses exactly the same electronics as the VCS 3, but rehoused in a Spartanite briefcase. Instead of routing signals using patch cables, as a Moog did, it uses a patch matrix with resistive pins. The 2700 ohm resistors soldered inside the pin vary in tolerance - 5% variance and later 1%. The pins have different colours: the 'red' pins have 1% tolerance and the 'white' have 5%, while the 'green' pins are attenuating pins having a resistance of 68,000 ohms.

The later Synthi AKS incorporated an early digital 256 event KS (Keyboard Sequencer) sequencer in the lid, input provided by a capacitance sensitive Buchla like keyboard.

Perhaps its most prominent use is in Pink Floyd's "On the Run" from their 1973 album The Dark Side of the Moon, as well as the introduction to The Alan Parsons Project's "I Robot." Along with Klaus Schulze and Tangerine Dream, other frequent users of the instrument include Tim Blake & Miquette Giraudy of Gong, Richard Pinhas of Heldon, Merzbow, Thomas Lehn, Cor Fuhler and Alva Noto.

From Wikipedia's page on the EMS VCS3

"EMS Synthi A randomness."

Used in studio and some live performances. In the picture, it's on the right side below the MPC60.

This is likely the Synthi A and not the AKS model, as this photo does not show the keyboard found on the AKS model.

Trent Reznor in his studio with an Electronic Music Studios (EMS) Synthi model A under the computer screen.

In this article on the making of David Bowie's "Heroes" album, producer Tony Visconti recalls, "Brian brought his EMS Synthi with him, which is a synthesizer built in a briefcase, and it has no real keyboard — it's got a kind of flat, plastic keyboard which Brian very rarely used. He used the joystick a lot, and the oscillator banks, and he would do live dialing — they look like combination-safe rotary knobs on the three oscillator banks."

EMS Synthi briefcase synth c. 1972. This is the same model as used by Eno on Discreet Music & treatments on various albums, including Heroes.

Multiple EMS Synthi A and an AKS can be seen in this photo of Jean-Michel Jarre and his large collection of synthesizers. The full size image can be seen here.

Kraftwerk utilized the EMS Synthi A synthesizer on their album "Radio-Activity," as detailed in the Kraftwerk FAQ.

"Kember's aforementioned EMS Synthi A was also much in use. "We ended up using it for the screaming sound on 'Lady Dada's Nightmare',” says Goldwasser. "That was just me staying up on the last night that we were recording in Malibu, right before we packed everything up. I was just making the weirdest noises. He's had some work done on it, a couple of the kind of common modifications. It has a soft sync built in, so you can get the type of oscillator sync sounds the Cars used all the time. But it's like it gets halfway there but it needs to catch up with itself, and sometimes it does and sometimes it doesn't, so it does this kind of throaty thing that sounds like a voice. So that's what that screaming thing is, this weird function of the soft sync.”

"We used it as a guitar pedal a couple of times,” adds VanWyngarden. "We had some wild late?night jam sessions. I had it one time with a Gretsch guitar with a Bigsby on it going through the Synthi and it just sounded like a dive?bomber. I was just doing it for hours, over and over.”"

This Electronic Musician article states that Murphy owns an EMS Synthi A.

In an article from Soundonsound, the EMS Synthi A is listed as part of Alan Wilder's equipment for his project Recoil.

Merzbow's gear in this image includes an EMS Synthi A, a UB1222FX mixer, and two Macbooks.