Doepfer A-100(~ 40 MB) - Manual (Page 64)

A-101-3 Modular Vactrol Phaser System A - 100 doepfer
8
stages can be obtained. The output of stage 1 does not
lead to a phaser but a high pass or low pass according
to the polarity of the signal fed into socket §. E.g. one of
the polarizers can be used to define the polarity and to
fade from highpass to lowpass and vice versa. To obtain
a phaser with 7-12 stages the output of stage 7-12 has
to be connected to socket § Shifted Audio In of the left
(!) unit as only here the original signal is available as the
second input of the mixer (the mixer of the right unit
does not have available the original that is connected to
audio input ! of the left unit).
% Polarizer In / & Polarizer Out / 5 Pol.
These elements correspond to the polarizer. The wor-
king principle of the polarizer is described in chapter 2.
The two sockets % Polarizer In form a "miniature
multiple" and are the input of the polarizer. Socket &
Polarizer Out is the output of the polarizer.
The function of the polarizer (i.e. the amplification in the
range -1...0...+1) is determined by the position of control
5
Pol.
The left one of the sockets % Polarizer In is normalled to
stage output 6. The output of the polarizer is normalled
to the feedback input of stage 1 (/ Feedback In 1).
Provided that no plugs are inserted a feedback loop from
stage 6 to stage 1 is established. In the middle position
of control 5 Pol no feedback occurs. At fully counter-
clockwise position maximum negative, at fully clockwise
position maximum positive feedback occurs.
To obtain different feedback loops the sockets % Polari-
zer In and & Polarizer Out have to be connected with
the desired output stages resp. feedback inputs.
By using the second polarizer or external modules (e.g.
VCA, VC polarizer A-133, filter, distortion, waveshaper)
even multiple feedback loops are possible - leading to
very interesting frequency responses with multiple reso-
nance peaks.
Another special feature of the A-101-3 are "forward
loops", i.e. it is possible to feed a stage output to a
feedback input of a higher stage (via polarizer).
By means of multiple feedbacks and/or forward loops in
combination with the positive/negative amplifications of
the polarizers and different controls and patches of the
stages 1-6 resp. 7-12 very complex frequency response
curves can be realized that cannot be obtained in any
other way.
/ Feedback In (6x)
These are the feedback inputs of the phase shifting
stages. Applications of these inputs have been descri-
bed on the preceding pages. The feedback input of
stage 1 is normalled to the polarizer output, i.e. Feed-
back In 1 is connected to the polarizer output - provided
that no plug is inserted into socket / Feedback In 1.