AD8400 as a remote trim pot

[Toby Paddock]

Posted to synth-diy at horus.sara.nl and analogue at hyperreal.org

In Analog Devices *Analog Dialog*, I saw a blurb on their AD8400/AD8402/AD8403 *8 bit digitally controlled variable resistor*.

Seems like a possible option to a 1 turn trim pot.

It is at
http://137.71.23.20/index.html
and do a Quick Product Search for AD8400

They talk like it's a real resistor with 256 possible taps as a wiper.  Uses some standard serial 3-wire interface.  Values of 1k, 10k, 50k, or 100k.  500 ppm/C.  1, 2, or 4 per package.

And then my random thought pattern went something like this?
Trim the trimmers in an instrument when it's warm and stable without opening it up.  The discussions on Yamaha CS synths comes to mind.  Battery backup power looks pretty low.  Maybe change settings as a function of some envelope (zipper noise problem?).  Gang 2 different values as a course/fine adjust.  Set up some autotune routine.  Replacement for a LED/LDR if 256 steps is enough. Could save favorite detuned *patches*.  I wonder if there is any ice cream left?

Hoping this finds you,
Toby