I've had my TRRI since 2008. (Have had nothing but Fender tube amps since 1965). I change all tubes annually, hell or high water, even though they do not need it. At about 450 volts I am able to easily bias at 38. That's fine and dandy for me. Leo designed the TR to stay clean at all volume levels. The output transformer would blow grits if one were to bias the amp up to a level where the tubes would be dissipating 30 watts each. It can't handle (OP tranny) the full wattage of 6L6's. But it also keeps the Twin the cleanest amp money can buy, which is why someone buys a Twin. Loud and clean. It still holds its own with a 100 watt Marshall. You know, local bars and night clubs are way too small these days for a Twin or similar volume amp that is way too loud by the time it hits its sweet spot.
