Doepfer A-151 Quad Sequential Switch - Manual (Page 5)

doepfer System A - 100 Quad Sequential Switch A-151
5
5. User examples
Switching VCO waveforms
In the example in Fig. 2, every time a trigger pulse hits
the A-151’s trigger input socket, the VCO switches to a
new waveform. Since very fast switching of the A-151
(by an LFO set to its fastest range, or even by a VCO)
can produce audio frequency modulation - that is,
changes so fast that the ear can’t resolve them - the
result is in effect a new waveform.
Fig. 2: Switching VCO waveforms
P As an alternative to using an LFO or VCO to
trigger the waveform sequencing, it’s possi-
ble to get the VCO to trigger the switching
itself. Simply connect the square wave out-
put into the trigger input ! of the A-151.
Four-step tone sequencing
The patch in Fig. 3 on page 6 produces a four-step
tonal sequence, with a different filter envelope for each
of the four steps.
An LFO simultaneously triggers ADSRs 1 to 4 and the
switch on the A-151, so that for each step the VCF is
affected by a different one of the four envelopes.
ADSR 5 is also triggered by the LFO, and controls the
VCA.
H It’s crucial to make the envelopes of all the
ADSRs fit the LFO’s speed.
A-110
VCO
Trig. In
A-151
SEQ. SWITCH
Res. In
O/I
I/O 1
I/O 2
I/O 3
I/O 4
LFO