Doepfer A-156 Dual Quantizer

The module A-156 is a dual quantizer for CVs, converting a continuous positive input voltage into a stepped output voltage. The steps have an interval of exactly 1/12V, ergo one semitone with the 1V/oct characteristic. This makes tuning an analog sequencer pretty easy but the module can of course quantise other control voltages like envelopes, noise or random signals.

The bottom unit allows you to chose from a number of different scales like minor and major scales, major and minor chord, fundamental plus fifth and addition of seventh or sixth when chords are selected. The operating mode is selected with toggle switches. Usually the upper unit works with chromatic scaling but after relocating an internal jumper the upper unit can quantise in the same scale as the bottom unit.

The A-156 quantizes constantly. If you put in a square signal to the trigger input the quantisation happens only at an incoming rising edge. This makes possible to synchronise the quantisation rhythically. A trigger signal is being output at the trigger out each a quantisation process happens. Additionally the A-156 has a common transpose input for a CV.