I love the Tung Sol 12ax7's in my 100w BM, I'm using Svetlyna 6l6GC's now for power tubes.
The Tung sol's are my preferred tube, I've tried just about every brand and for OD they kill. JJ's sound decent too but they lack the detail that the TS's give.
I had Sovtek 6l6's in before the Svetlyna's and they lacked something IMO
I'm going to try some old Telefunkin and Mullard (ecc83's) some time this week!! Got a guy that wants $25 a piece for them /tested just under good on a B&K 707