Greetings! I'm bidding on an AK auction, and suppose I should ask before I *acutally* win...does anyone know / care to opine on how well some RCA 5963s would work in my Conrad Johnson PV-12? I'm totally new to tube-audio, so I have no idea what I'm doing... I presume if the slot calls for a 12AU7 tube, I can put any 12AU7 tube in there and it will work, albeit with differences based on the particulars of the tube in question. Is that correct? And I have no idea what my PV-12 uses its AU7s for, whether it's for a phase splitter function or not. I guess what I'm really asking is, would this be a dumb auction for me to win if I'm planning to use these only in a PV-12?