[sdiy] TDA7052A as VCA

[David G. Dixon]

One obvious place I can think of to use this is to add VC resonance to an
existing filter design where all the OTAs or VCAs are already tied up in
other duties (I'm heavily immersed in filter design at the moment).  In
fact, one could use this to add cheap VC to just about anything, and you get
the inverse for free (if I've deciphered the datasheet correctly).  The
"switch-off" feature at low gain may even be used to advantage in some
situations (like decisively zeroing the damping factor in a state variable
filter).