Audio note potentiometer
http://www.partsconnexion.com/anote_72544.htmlI would also pick up a few pair of NOS 3s4 tubes, I have settled on two sets that I really enjoy. Some amperex bugle boy from the 60's for the majority of my listening, rock, electronica, metal, hip-hop... and a set of 40's tung-sol that have a very seductive mid-range that I like to listen to blues and jazz with. I buy most of my tubes from tubeworld.com.