Digitally controlled tone stack?

[stormbringer79]

Hey, i usually build analog effects, but my latest project i would like to control everything with a mcu.

I know there are digital potentiometers, but i also read alot of complaints about them. Anyone has a schematic of for example a digitally controlled tone stack? I was thinking about pwm signal controlling transistors? Any tips welcome.

[markseel]

Check out the voltage-controlled amplifiers from THAT Corporation.  You can use them to build analog filters with gain and frequency adjustments controlled via DC voltage.  You could then use an MCU to create PWM that's low-pass filtered and buffered (with an op-amp) to drive the VCA control input.  Or you could just use a low-cost SPI or I2C controlled ADC.

[snarblinge]

what are the complaints?? i have a project on the bench that will be mcu controlled. interested to know what to expect