New production tubes have left me wanting and even my favorite 6V6's drift, ping and rattle too quickly and too often. I was surprised when my Louis Electric Columbia Reverb came loaded with EH with a Sovtek 5AR4. EH has been my least favorite glass. Though they work fine in most positions in the preamp section of this amp, their grind and grit was not my cup of tea in V1 or as output tubes. New sets of Tung Sol (my used-to-be favorite new production) have been so inconsistent and have drifted into oblivion in short order. JJ 6V6's sound quite good but not what I'd call sweet sounding, and have experienced inside the glass rattles in combo amps prior, though not in my last set, which I've stashed. Enter TAD STR. I've tried the 6L6 STR (this amp uses either) and was very satisfied but long for the 6V6 qualities. When I learned that TAD released their version, designed to be reminiscent of the old RCA and GE but built to handle modern power supply and high plate voltage, I had to try them. I'm here to say I've never been happier with a new 6V6GT, nor has any new offering come close to its full dynamic range and overall sweetness. Bottoms are surprisingly big and tight, highs are bright, and mids are plump and juicy. It took a couple hours to burn them in, even though the select premiums are thoroughly tested. I've also reached the same conclusion for their 7025 for V1. All three TADs mentioned still have to pass the test of time in this amp, but so far I give them a thumbs up, particularly their new 6V6GT. Exception being their 6L6STR and 7025, which have been going strong in my Richter RS-33 for well over a year. I'm hoping their 6V6GT hold up as well. Also, I've been very happy with Antique Electronic Supply's customer service. I don't mind paying a little sales tax to my own state of AZ. They've been great.