hello,

yesterday i checked the bleed-through of the
a101/2 lowpass gate in vca mode. well, there
is a noticeable bleed-through in vca-mode, but
not in the other two modes (lp and lp+vca).
the bleed-through can be heard when the a101/2
output is the only audible signal. this shouldn't
happen too often in standard applications, but in
certain cases it can be problematic of course, for
example if you use a compressor afterwards.
if such problems occour, i'd advise to use a noise gate
or move over to a dedicated vca like a130 or a131.
on the other hand the a101/2 has a very nice
sonic quality and i use it in vca mode quite
often, because the sound is so nice.
but thats the deal with vactrols, they also
have their disadvantages. technically the
typical vca's like a130 and a131 are better,
they respond faster, more exact and they can
fully attenuate a signal. but sometimes the
slow a101/2 is the better choice soundwise
(my taste of course, others may disagree).

in the following example i used a swept a110
sawtooth wave at the lpg input.

a101/2 settings:
f/a = 0
cv2 = 0
lev = 3
res = 0
mode = vca

then i used a gate signal coming from an a179
at the cv1 input to open the lpg.

http://www.selfoscillate.de/a100files/a101-2-bleed.mp3

listening at normal volume you shouldn't hear too much
of a bleed-through, but if you load the example into a
wave editor and zoom in, you can see it. if you cut out
the loud part of the recording and turn up the volume
you can also hear it. you have to decide on your own if
this is a problem. for me it is no problem at all.
i mean, this is an analogue system and a bit of
background noise is normal. in 99 % of all cases the
bleed-through will be masked by other sounds and noises.
in the end, nobody will notice it.

best wishes

ingo