I'm looking for a good volume control. Just a volume control. I am helping a friend build a 2 channel system who is looking for a way to control the volume going from his source to amplifier. He's looking for something cheap and only has one source to deal with, so I was thinking that there might be a good component which has only one input/output attached to a high quality dial? However, I don't know of any and am looking for suggestions or other work arounds.