Quality and TONE!!!
Just received a pair if these for a Mesa Express 5:50. As soon as I grabbed one outta the box, I knew these were quality tubes. The thick glass envelope is heavy in your hand, and the tube pin soldering looks great! Tonewise, these are BIG and BOLD sounding! Big deep lows, punchy clear miss and really nice sweet highs. My favorite thing about them...Headroom! Clean tone for days. I gotta say that these really do give the NOS Philips 7581A's a run for the money. Very satisfied with these!!!