Telefunken ECC83/12AX7, are good. But so are Amperex Bugle Boys, Mullard CV4004, and for that matter, Sylvania Black Plate 12AX7's. They're just different sounding. In the right system, to the right tastes, all of them will produce magic. Telefunkens, are smooth, rich, warm tubes, with a rounded bass. Amperex, are robust, dynamic tubes, with an excellent bass. The Sylvania's are lively, not as rich sounding, tubes. So only with system, and personal tastes matching, will you acheive, the magic, you are looking for.
12ax7's
PARAGON PREAMP THAT USES 12AX7'S....I NEED TO KNOW
WHICH ONES WILL CREATE MAGIC...
WHICH ONES WILL CREATE MAGIC...