Behringer System 55 Complete Eurorack Modular Synthesizer

Modular Synthesis
The first System 55, 35 and 15 synth modules came out in the early '70s and tended to be extremely expensive. They were mainly all discrete transistor designs as op-amps at the time were very high cost. The discrete circuitry gave the modules a very distinctive sound and were used by artists like Keith Emerson, Stevie Wonder, Tangerine Dream and so many more, giving us some of the greatest records we’ve ever heard. Modular synths were a landmark development in electronic music and today, it’s about to get better.

Voltage Control (pitch)
Source
Destination

External MIDI Keyboard – MIDI Out
CM1A MIDI Interface MIDI In

CM1A CV Output
921A Frequency Input

21A Frequency Output
921B Frequency Link (in series)

Audio
921B Waveform Outputs (three of four)
CP3A-M Inputs

CP3A-M Output
904A Signal Input

904A Signal Output
902 Signal Input

902 Signal Output
Your mixer/amplifier/DAW

Voltage Control (amplitude)
CM1A s-trigger Output
Multiple

Multiple Output (three of)
2 x 911 s-trigger Input & 911A s-trigger Input

911A Output
3rd 911

1st 911 Output
1st 902 Control Input

Voltage Control (modulation)
2nd 911 Output
904A Control Input

921 Aux Sine Output
2nd 902 Signal Input

2nd 902 VCA Signal Output
CP3A-O Input 4

CP3A-O Outputs
921B DC Mod Input (three of )

3rd 911 Output
2nd 902 Control Input