It's an O2 thing as far as I am concerned. They need more than the 007t or 717/727 can offer to sound even decent. They can sound good on the Woo GES, but not great. They can sound pretty great on the ES-1/2, but not fantastic. And they are probably taken to their greatest level by the KGBH/SE as far as I have heard them. I wonder if a really powerful amp, say my McCormack DNA 500 with massive wattage could power a Stax trafo box and make the O2s come to life a bit. Should have tried it with Gene's Accuphase in Tampa but I just forgot.