doepfer
System A - 100
MCV 16
A-191
5
Fig. 1
:
The sawtooth (1/2 note cycle) generated by
a MIDI controller value of 8.
Table 2
: Typical values for controller #92 and the
resultant length of the LFO cycle.
H
Because the A-191’s LFO is purely a
soft-
ware
device, the following considerations
apply, which it’s well worth remembering.
The A-191 uses an 8-bit D/A converter, whose maxi-
mum resolution is 256 steps per 0.02 V. Conse-
quently, the
sawtooth
and
triangle
waves can’t be as
smooth as, for instance, those of the A-145 LFO. The
waveforms on the A-191 LFO are
digital
("stepped").
If you use it to control, eg, a VCO, the result is less of
a smooth continuous pitch sweep, and much more
akin to a glissando. How audible these steps are
depends on the MIDI-Clock
tempo
, and the
divisor
you’ve chosen.
P
If the steps are audible (and unwanted), you
can use a
Slew Limiter
(A-171) to smooth
out the waveforms.
Erratic or sudden changes of tempo
or the
divisor
will take a whole note to register, before the LFO
changes to this new frequency.
Controller value
LFO cycle
0
LFO off
1
1/16
2
2/16 = 1/8
3
3/16
4
4/16 = 1/4
8
8/16 = 1/2
16
16/16 = 1 whole note
32
32/16 = 2 whole notes
64
64/16 = 4 whole notes
4
4
