I just picked up a used 2004 Deluxe Reverb Reissue and it has a poorly performing Russian 5AR4 in it, the center pin was snapped off and I cant get more than 29 ma per tube fully cranked on the bias pot. Yes 29 is enough but..... at full tilt that's boarder line low. I swapped out the tragically weak Groove Tube 6V6GT's for some sweet Sylvanias and put a Weber 12A150 alnico 50 watt 8 ohm speaker in there that I've had for several years. Sound Great ! However how long can I trust the sov-tech GZ34 ??? not long I'm guessing. Any way I see a bunch of 5V4GC out there and their pretty cheap ! and just as durable as the famous older versions of the 5AR4 right ? Without getting too technical and without talking about that other tube (5U4GB) Has anyone found happiness with a 5V4GA in a DRRI ??? Or did it lose too much bass response, Get flabby ???