Authentically recreated, Behringer’s 921A oscillator driver delivers the circuitry, sounds, and experience of the vintage 70s System-55 module in modern Eurorack format—at a price that makes creating a customized modular synth an affordable reality for anyone.

The 921A Oscillator driver works like a master controller for up to (12) 921B oscillators (or other analog oscillator modules), driving overall frequency and rectangle wave PWM. The frequency control knob lets you dial in 12 octaves of frequency (6 up/ 6 down) or break down an octave into 12 half-steps (up/down) with the 2-way switch. The width knob gives you control of rectangle wave PW (10%-90%). Connect your performance keyboard or other modules with (2) summed 3.5mm CV control inputs for frequency and pulse width, In and Out.

• An authentic recreation of the 1970s vintage classic 921A oscillator driver module
• Two summed CV control inputs for both frequency and pulse width
• Drive up to 12 Behringer 921B Oscillators
• Size 8HP Eurorack
• Requires Eurorack case and power supply