I play guitar so that helps me understand what you are getting at. You've got some sort of voltage-controlled analog effect box circuit that you'd like to put under digital Arduino control by using PWM and an R/C filter to generate the control voltage for the effect. I've thought of that before, and it would seem to be fine in theory (if your circuit is happy with 0-5V for your analog control, and doesn't take too much current); otherwise as mentioned you'll want an op amp to get a different range.
PWM driven led coupled with a 'slow' photocell?
TCCR1B = TCCR1B & 0b11111000 | 2;[/quote]Will bring the PWM frequency on pins 9 and 10 to about 3.9KHz.
If you want to use PWM for clean audio, I suggest you reprogram the registers to crank the PWM frequency up. It will make filtering ALOT easier while keeping the audio intact.Code: [Select]TCCR1B = TCCR1B & 0b11111000 | 2;[/quote]Will bring the PWM frequency on pins 9 and 10 to about 3.9KHz.