Archive of the former Yahoo!Groups mailing list: eml synthesizers

While the concept of CV (Control Voltage) was fairly standard on analog synths, the implementation was not. For pitch control via CV, there are two prominent implementations:

• Volts per octave. This standard was popularized by (if not created by) Bob Moog in the 1960s; it was widely adopted for control interfacing.One volt represents one octave, so the pitch produced by a voltage of 3 V would be one octave lower than that produced by a voltage of 4 V. Notable followers of this standard include Roland, Moog, Sequential Circuits, Oberheim and ARP.

• Hertz per volt. This method (used by most but not all Korg and Yamaha synths) represented an octave of pitch by doubling voltage, so the pitch represented by 2 V would be one octave lower than that represented by 4 V, and one higher than that represented by 1 V.

The following example table demonstrates some notes and their corresponding voltage levels in both implementations (this example uses 1 V/octave and 55 Hz/V):