[sdiy] Digital control

[Johannes Öberg]

I'm thinking about building some simple analog FX modules, mainly a
compressor and a filter. However, I would really like digital control
over them; at least patch memory. What's the simplest/cheapest way of
implementing this? I have some experience with PIC programming, so I
guess what I need help on are some digitally controlled resistors or
something, to replace the pots.

Sorry if this is a silly question but I don't know much about analog
circuitry. I guess I could use digital potentiometer IC's but all I've
found seem quite expensive and offer very poor resolution. I'm hoping
there are some DIY circuits. I wouldn't need fast settling times or
anything as I only intend to replace semi-static pots with digital
control (like attack and release knobs etc. on a compressor).

Greets
/Johannes