The Black VCO, from Erica Synths, is a refinement of their dual oscillator set, the Black Varishape VCO 1 and 2. It is roughly inspired by the architecture of the Polivoks VCO, but instead of harsh logic-divided suboscillators, the Black VCO uses transistor based circuits to generate a slightly more rounded square wave. It contains simultaneous Sine, Tri, Saw, Pulse and Suboctave outputs, with 1V/Oct tracking over 8 octaves, an FM input with attenuator, a Sync input, and Pulsewidth mod with a pulsewidth offset control. 

When paired with the Black VCO Expander, waveforms can be mixed in a variety of ways, providing a larger timbral sound palette. It also provides two octaves of suboctave outputs. 

• Simultaneous sine, triangle, saw and pulse wave outputs
• -1 octave suboscillator
• Manually adjustable and CV controlled
• Pulse width control and mod input
• Great tracking across 8 octaves
• Exponential FM input with attenuator
• Synchronization input
• Octave switch – 5 octaves
• Skiff-friendly design