[sdiy] Digital pots as the gain element in a filter

[Olivier Gillet]

Hi all,

I always thought this was a whacky idea - especially since it would
give only an approximate expo response through one of those "linear to
pseudo-audio" pots trick - but someone ended up doing it!
http://hackmeopen.com/wp-content/uploads/2011/05/Rockit-Schematic.png
(From: http://www.kickstarter.com/projects/790206393/rockit-8-bit-synth-kit?ref=live)

Do you know of other designs using something like this?

Olivier