TRRI hums, with all controls on 0 and nothing plugged into the input jacks. Hum volume increases as amp volume knob is turned up. Very annoying. Bought this here on TGP and it just came it today. I did a search and i see that i could get past this by some preamp tube changes. Can I use JJ ECC83S or ECC81 in place of the 12AX_7?? Have some of these from my HRDx... I plugged in and while playing the hum is of course covered up by my guitar, but in a band situation where i'll be mic'd and we break in a song, i don't want "hummmmmm" coming from my side of the stage.. what to do, what to do? ALSO - the HRDx had that page run by Justin Holton, or something like that. Does the Twin Reverb RI have such a page??