Thanks very much Ooslik...I just received some of the earliest RCA 6SN7GTs, and will try them in my system. I am also waiting to receive a few nice sets of early Ken Rads as well as single set of the Tungsol Rounds. Like you, I have on hand an early Mullard GZ34, but also a Mullard GZ33 and an Amperex 5AR4. The thuds and microphonics vary, of course, depending on what tubes are being used. In most instances, I can live with those issues. I just want to scotch the glare bugaboo. Beyond that, the Cortese is a wonderful unit. I have my slightly modified Air Tight ATM-3 monoblocks, and an extremely fine ribbon/driver hybrid pair of speakers built by the brilliant friend I alluded to in my previous comments. Then there's my Dunlavy SC-IVs, which are sitting in taped boxes in another room. As much as I enjoyed them, I have enjoyed the hybrids even more. Okay, enough for now. thanks again for the [hopefully] reassuring words.