⭕ Up for sale is an analog synthizer: EMS Synthi AKS, with KEYBOARD Prestopatch. This synthesizer needs no introduction. It is one of the very early models with the 18 dB/octave filter response, indicating it was built before 1974. This unit has a 30 note touch capacitive keyboard. Keyboard Prestopatch is included. Printed dope sheet of control setting for the patch is in the manual.
This Synthi is all original. Bulb for envelope shaper was replaced, reverb IC was replaced and resoldered wires to the reverb. These repairs were made using parts ordered directly from EMS. This is a vintage machine and as such has the some slight wear patterns and case scratches you would expect in an old machine. The numbers around the levels on channel 1 and 2 have some fading and are not clearly visible. The face plate around the umbilical plug in show signs of wear. Minor fading around the oscillator frequency labels but readable. Closing the case is tricky, the ABS bottom portion where the keyboard is housed for travel, has a slight warp and must be pulled slightly to fit into the ridge for proper closing. Included is the manual, power cord, umbilical cable, and an EMS synthesizers bumper sticker.

Technical Specifications

Oscillator 1: Range: 0.5Hz - 20kHz

Output: Sine (with variable shape) and Sawtooth

Oscillator 2:Range: 0.5Hz - 20kHz

Output: Square and Triangle

Shape control gives variable pulse width and rising or falling ramps.



Range: 0.025Hz - 500Hz

Output: Square and Triangle (shaping as per Oscillator 2).

Noise Generator:White and variable colored noise.

Range: 5Hz -- 15kHz

Oscillator: Cut-off Rate: 18 Db/octave max.

Low-pass with variable resonance and sinewave oscillation

Ring modulator: Transformerless integrated circuit design.

Input Rejection: 60dB

Envelope Shaper:A programmed variable gain amplified of trapezium format with analogous voltage output.

Timing: Attack: 2mS - 1s

On: 0 - 2.5s

Decay: 2mS - 15s

Off: 10mS - 5s + recycle inhibition

Triggering Modes: Via +4 volt from keyboard socket

Manual trigger from attack button

External signal input level threshold detector

Self-triggering in recycle mode

Decay time is voltage controllable from patchboard

Reverberation:Dual spring-line unit with delays of 25mS and 20mS. Max reverb time 2s.

Meter:For Signal Level or Control Voltage monitoring Also indicates memory availability when used with sequencer keyboard.

Inputs:2 input channels (1/4 mono jacks)

High-level line inputs: 2.5V into 50Kohms

Microphone inputs: 5mV into 600 ohms Both channels suitable for external CV inputs


Outputs: 2 output channels (1/4 mono jacks)

Signal Outputs (via VCAs): 2.5V into 600 ohms (with filters and panning).

Control Outputs (pre-VCAs): 10V into 10Khoms Headphone output: 10V into 50 Ohms (stereo 1/4 jack)

Scope output: 10V into 10Khoms (via meter row on patchboard)

Power supply:240 or 115 Volts AC. 50-60Hz. 25 watts.

VCS3: 43 x 44 x 42cm.

Synthi A: 48 x 38 x 12cm.

Weight: VCS3: 9kg

KS Specifications:Synthi A: 7.5kg

Power Supply:+12 and -9V through umbilical from synthesizer power unit.

Sequence Length:Range at least 700mS - 100S (time for 256 clock pulses).

Storage Capacity:1536 bits in 256 x 5+1-bit words.

Memoty:Shift register.

Keyboard:30-note capacitive touch keyboard, plastic coated for protection from humidity and damage.

Real Time Pitch Voltage:Mean 1V/octave adjustable +/-10%

Sequence Pitch Voltage:Mean 0.32V/octave adjustable +/-10%

Sequencer Ripple:30mV p-p (worse case--5th transpose pad only)

Touch Pads: Record; Play; Random Voltage; Transpose 1/2-tone, tone, major 3rd,5th.

Controls: Clock Rate; Pitch Spread (x2); Trigger Select.