Oktave

The ACL Oktave is made with two main functions in mind: transposing any sequence or melody up or down by up to four octaves, and fine tuning a signal up or down by nearly seven semitones. It has three high-impedance inputs, one low-impedance inverting output and four low-impedance non-inverting outputs, so it can control the pitch of up to four VCOs at once, and it can also mix up to three incoming CV signals and add DC offsets to them. Octave tuning is set with a high-quality nine-position rotary switch spanning -4 V to +4 V, with 0 V in the centre position; fine tuning of the input mix is handled by the TUNE potentiometer, with a range of a little less than a fifth either way. A precise on-board voltage reference, low-tolerance resistors and low-noise, low-drift operational amplifiers keep octave tuning and offsets accurate.