On top of that, Guy will attempt to select resistor values to match your source gear and gain of your system if you can give him some info about your current setup. He did this for me as my cd player source is a bit on the hot side at 3v out of the RCA jacks. I can barely even detect the difference in sound level between a single step and at moderately loud (normal) volume levels I'm approximately midway on the control range at a little under 64 steps of 128 available.