I've been rolling some EL34s through my little amp, and picked up an Apex matched pair of Valve Art. They were inexpensive, but so far out of JJ KT77. EH 6CA7 & EH EL34, they have the sweetest, smoothest midrange yet. Funny though...they aren't exactly matched - at least not physically. One is about 3/8" taller than the other. What the heck - loose quality control perhaps? Should I just use them and be happy? Thanks!