I'm making a digital synth for a project and I need to wire in an Arduino-controlled volume circuit.
Right now I'm outputting a 0-5V audio signal and cutting it down to a pure AC 0.5V signal with a voltage divider (1kohms and 10ohms) and a capacitor. I would like to tack on a digital potentiometer to this circuit to control the audio volume so I bought a DS1807.
The datasheet is here but I'm still not totally sure how to use this -- it refers to the resistor settings in db rather than ohms, but it feels like I should be putting in a second resistor to form a voltage divider with it. What should that resistor value be? I don't see a reference to what the actual resistance of the DS1807 varies between. Or am I thinking about this circuit completely wrong?
(p.s., the speaker we'll use is a powered computer speaker)
Here's the circuit I was thinking of-- is that correct and how do I choose R3?