I have two pairs of Telefunken ECC801s, and 4 pairs of Valvo 6201 - 1 - pinched waist double post o-getter blue Valvo, 2 - pinched waist single post o-getter (unbranded for export, Valvo codes), 3 - solid disc getter, single post (philips branded, Valvo date codes), 4 - o getter single post (philips branded, Valvo date codes). The ECC801s and the 6201 are the best tubes I've heard. Both have incredible dynamics, huge soundstage and depth, separation, and detail retrieval. I'd say the Telefunken seem slightly more dynamic, and more neutral in the mids, though the increased dynamics on the tele could be due to the more neutral mids not masking the transients. I'm hard pushed to pick a favorite between them. I also have a pair of Mullard 6201 on the way, along with 30 other various 12at7 types. I'll report back on findings, but I don't expect any of them to come close to the Tele ECC801s or the Valvo 6201s.