Doepfer A-101-3 Vactrol Modular Phase Filter - Manual (Page 4)

A-101-3 Modular Vactrol Phaser System A - 100 doepfer
4
that no plug is inserted into this socket. To obtain a
phaser with more or less stages the output of the corre-
sponding stage has to be connected to the socket
"Shifted Audio In". To obtain e.g. a 12-stage phaser the
output of stage 12 has to be connected to "Shifted Audio
In" of mixer 1.
The polarizer is intended to control the feedback
loops. In principle a polarizer is an attenuator. But in
contrast to a normal attenuator it enables both positive
and negative attenuations (i.e. amplifications in the
range -1...0...1). Negative attenuation resp. amplificati-
ons means that the signal is inverted (look at the manu-
als of A-133 CV Polarizer or A-138c Polarizing Mixer for
details). The middle position of the polarizer control
corresponds to full attenuation (or amplification = 0).
This corresponds to the fully counterclockwise position
of a "normal" attenuator. The fully clockwise position
corresponds to amplification +1 (i.e. the signal passes
unchanged), the fully counterclockwise position corre-
sponds to amplification -1 (i.e. the signal is inverted).
The "Polarizer In" socket is normalled to stage output 6.
Consequently the output of stage 6 is used as polarizer
input provided that no plug is inserted into this socket.
The polarizer output is normalled to "Feedback In Stage
1". Consequently the feedback loop "stage 6
→ → → → stage 1"
is active without external patches and the polarizer
control is used to adjust the feedback intensitiy and
polarity (remember: zero feedback corresponds to
middle position). On our web site a lot of examples of
single and multipe feedback loops are published
(available via A-101-3 information page).
And this is the result from all these response curves:
• The number of notches is defined by the num-
ber of stages used as output (number of not-
ches = integer of the stage number/2)
•
The number of resonance peaks is defined by
the number of stages used for feedback
(number of peaks = integer of number of feed-
back stages used/2)
•
The height of the resonance peaks is deter-
mined by the amount of resonance (adjusted
with the polarizer)
By means of the open modular concept of the module
A-101-3 different numbers of notches and peaks are
possible by using the corresponding patch for output in
use and feedback loop(s) !