If you feed a sine into both inputs of a ring modulator, you get a sine an
octave higher, not a rectified sine. It outputs the sum and difference
signals, so the sum of "1" and "1" is "2 (doubled frequency)," and the
difference is zero. This only works for sines, of course, because any more
complex signal gets immediately non-linear.
I'm not sure where you're getting the rectification from. You can do some
rectification with a few diodes, but that's usually used for AC power. For
audio applications, there're ways of rigging an op-amp to do that, I think.
I wonder if you could... have your signal split up and fed into two VCAs,
one inverted phase, and also use the signal as the control signal for the
VCAs... naw, that's crazy... ;)
-----Original Message-----
From: Thomas Hudson [mailto:
thudson@...]
Sent: Wednesday, 05 December, 2001 7:33 PM
To: MOTM
Subject: [motm] My failed experiment
I had this bright idea for creating an envelope follower
from the current offering of modules, and while it does
work somewhat, it is not quite "there," and I'm trying to
figure out why.
Here's what I did. I took the output from my guitar preamp
and ran it into both sides of the ring modulator. This
should create a sort of rectified signal. I then took the
output and ran it into the lag processor, which should
give independent attack and release times for the rectified
signal. I set UP (attack) to min and DOWN (release) to about
5. I ran this output to the FM input of a filter, and my
guitar preamp out to the input of the filter. The filter
does follow the input amplitude somewhat.
I guess I'm wondering if my assumption about the ring mod
doing rectification is correct. I know it is true for a sin
wave. Perhaps if I used the 700 to switch between +/- 5
on the zero crossing of the guitar signal, and used this
for the Y-input of the ring mod?
Tomy