Well I'm finally trying my little new V2 amp. I almost immediately changeg the stock tube. I think it sounds decent overall but on stoner rock songs the instruments are blurred and I can't appreciate the voice. Even if basses and highs are defined, mid ranges are totally killed. I am trying these new tubes now, a Philips: And a jugoslavian International Servicemaster Electron Tube I can say they improve greatly the amplifier though I prefer the second one. I think it can manage better the whole amplifier. I would like to try an RCA clear top.