Doepfer - A-156: Dual Quantizer

Manufacturer Description:

module a-156 is a dual control voltage quantizer. a quantizer converts a
continous control voltage in the range 0...10v into a stepped output
voltage in the same voltage range (i.e. only certain voltages occur).
normally 1/12 v steps are used to obtain semitone steps. quantizer 2 of
the a-156 allows has more sophisticated quantizing modes like major
scale (i.e. only voltages corresponding to the major scale), minor
scale, major chord, minor chord, fundamental+fifth and addition of
seventh or sixth when chords are selected. only those voltages appear at
the cv output which comply with the selection rule (e.g. minor chord
with seventh). the mode setting of quantizer 2 is done with 3 switches
(1-0-1 type with middle position). quantizer 1 is working always in the
semitone mode.

for each quantizer the following in/outputs are available:

* control voltage input (cv in): the input for the contiuous voltage to be quantized

* control voltage output (cv out): the output of the quantized voltage

* trigger input (trig.in): if this jack is left open the quantizer is
working permanently. if a rectangle voltage is applied quantisation
happens only at the rising edge of the signal (e.g. from an lfo or
midi-to-sync interface). thus the quantizing can be synchronized with
other events.

* trigger output (trig.out): whenever a quantisation happens (i.e. a new
voltage is generated at the cv out) a positive pulse occurs at this
output. it may be used to trigger an envelope generator (adsr) or for
triggering other modules (sequential switch a-151, trigger
divider/sequencer a-160/161, trigger delay a-162, ...). if none of these
functions are used the jack is left open.

on top of that the a-156 is provided with a common transpose cv input
having an additive effect on both quantizers. this input is quantized in
semitone steps. a typical application is the transposition of a
sequence generated by the a-155 by a second control voltage (e.g. coming
from the midi-cv interface a-190).

typical applications:

* quantizing the cv sequence generated by an a-155 (semitone, onyl major scale, only minor scale and so on)

* quantizing the voltage coming from the trautonium manual / ribbon
controller a-198, theremin a-178 or light-to-cv module a-179 to get
accurate semitones or major/minor scale tones

* arpeggio-like effects with lfo, random, noise, envelope generators as
cv sources (for negative or symmetrical voltages an offset must be
added, e.g. with the offset/attenuator module a-129-3, to obtain
positive voltages for the a-156 input).

this module has a maximum current draw of 50ma. it requires 8 te/hp worth of space to fit in a eurorack frame.