This is the modified unit with no meters I was asking about. It's a heavy sucker! I was thinking I could hook up my iPhone and/or Sirius radio with a cable I have, with a mini headphone jack on one end and RCAs on the other. The amp has sockets that are bigger, I'm guessing they are the same size as large headphone jacks? Left and right, labeled "Normal Coupling" and "Direct Coupling" with a switch. I guess PL700 owners know what I mean. What can I do, I want to try this thing out, and I don't have a preamp(yet).