I am trying a trio of matched SYLVANIA JAN 6DJ8/ECC88 "Green Hornets." They sound a little better to me than the ones I usually run, a set of Matsushita / National PCC88 / 7DJ8 Cryo'd from Upscale. I haven't quantified it yet, need some more hours. Nothing wrong with the Upscale tubes, they are fantastic...very reasonably priced too at $43 for cryo'd, platinums. I can't tell anything about the cryo part, as I've never ordered any from Mr. Deal that weren't. I just sold another PH-3 running 6H23's, also from Upscale. They sounded great too, perhaps a little more laid back in my system. Call Kevin at Upscale. He can be very helpful. Across three different PH-3's I got too much sibilance/harshness from factory tubes. With the caveat that YMMV, of course.