Check the listing for details. Behringer 921B OSCILLATOR - Analog VCO Eurorack Module. Condition: New. Listed at 55.90 USD. Old-school Voltage-controlled Oscillator for Eurorack A historically accurate reproduction of a legendary 1970s synth module, the Behringer 921B OSCILLATOR is filled with vintage grit and old-school growl. This straightforward all-analog VCO simultaneously outputs sine, triangle, sawtooth, and square waveshapes, and it includes two CV inputs for pulse width modulation and AC-Coupled and DC-Coupled inputs for frequency modulation. Sync in with selectable weak and strong modes lets you slave the 921B to another oscillator for deep waveshape manipulation. Just like the original unit, the 921B is not a standalone unit and requires a Behringer 921A OSCILLATOR DRIVER. When paired, these two units generate some of the creamiest, grimiest oscillations synthesists at Sweetwater have ever heard.