The Behringer 921 is a faithful reproduction of the original 921 VCO module that was the heart of the legendary modular system from the 1970s. And like the original, the Behringer 921 generates massive, gritty tones with its six selectable waveforms that include sine, triangle, saw, inverted saw, square, and inverted square. Or, you can switch it into sub-audio mode for use as an LFO. The 921’s frequency control lets you select between stepped octaves or semi-tones, allowing you to create pseudo-polyphony when paired with one or more additional oscillators. For ultra-thick sounds, the 921 features pulse width modulation with two separate CV inputs, and you can add a heaping helping of dirt by adjusting the module’s clamping point, a type of old-school clipper. Eurorack has caught fire amongst synth enthusiasts at Sweetwater, but we realize that building a modular system can be an expensive affair. However, with Behringer’s affordable line of Eurorack gear, neophytes and seasoned synth wizards have unprecedented access to a huge selection of well-priced modules with world-class sound.