Using SSM2018

[pocino]

I just read a good article in the AES Journal about using the SSM2018 as a
voltage controlled pot. It describes a couple of different panners (the
datasheet for the 2018 has one), but also a mixer (sort of like using the
pot the other direction to mix between 2 signals).  I was thinking this
would be a cool way to do something like a voltage controlled "vector
synthesis" thing. Anyway, the cool thing I got out of the article was how
you could make a voltage controlled pot with a 2018.  The problem is that
the circuits need the same impedance on both outputs or inputs (depending
on where the source is).  This isn't a problem for something like a mixer
or panner, but it would be nice to be able to universally replace a pot
even if the impedances weren't the same. If somebody has experience doing
this, or can figure out how to get around the problem that would be great.
Otherwise, I think this is still quite a handy article. It's in the AES
Journal, volume 39 number 10 page 775 for those who have access.

If people would like to see some schematics from this thing, let me know.
I didn't want to spam with a big ascii thingy if this was old hat to
everyone. If someone wants to put it on a web page I could draw a .gif (I
don't have a scanner, and I doubt we want the whole article anyway) or
attempt an ascii one. Maybe this could be the start of a nice tutorial on
how to replace pots with something voltage controlled.

Mike