This circuit takes a square wave signal from 0 to +5000hz and convert the signal to 10% or what ever you wan't.
you can try to chance the values of the capacitors connected to 2 and 6 of the 555t and the resistor.
I have tried to connect this circuit to my own DRSSTC and it worked perfekt and played music using an arduino.
If you is interested in this try look up my youtube channel (hanberg engineering) here I'll upload it when I'm finish with everything.
