Doepfer A-100(~ 40 MB) - Manual (Page 521)

doepfer System A - 100 Quantizer A-156
3
3. Basic Principles
A quantizer consists of an analog/digital converter
(ADC) and a digital/analog converter (DAC). The vol-
tage applied to the analog input of the ADC is conver-
ted into digital information (e.g. 6 bit = 64 steps). The
DAC converts this digital information back into a quan-
tized analog voltage in the same voltage range. For
pitch control voltage applications following the 1V/oct
standard an ADC resolution of 1/12V (= 0.0833V) is
used.
Module A-156 contains 2 quantizers. The factory set-
ting for
quantizer 1 is a semitone grid (i.e. voltage
steps of 1/12 V, see fig. 1).
H
If the position of jumper J1 on the A-156 circuit
board is changed the first quantizer has the
same features as quantizer 2, i.e. the 3 switches
determine the behaviour of quantizer 1 as well.
Quantizer 2 enables other grids than just semitones,
e.g. major scale, minor scale, major chord, minor
chord, fundamental + fifth and the addition of a sixth or
seventh to chords. This means that only such voltages
appear at the control voltage output that meet the
selection criteria (e.g. minor chord with seventh) set by
the 3 switches.
fig. 1: Quantizing in a semitone grid (1/12 V)
Quantization takes place continuously if the trigger
input of the quantizer in question is not used (i.e. if
nothing is plugged into the trigger input socket). The
internal quantizing rate is about 500 Hz in this case. If
a rectangle signal is applied to the trigger input (e.g.
from an LFO, sequencer trigger output, MIDI-to-Sync
interface) the quantization happens only during the
low/high transition of the trigger input signal. Thus the
quantization process can be synchronized to other
events.
1
12
V
: CV In
: CV Out