Brimar vs Tung Sol 12at7

Depends on inside construction and production year they are, but in general, Brimars are warmer, so, if you are going to use TS 6550 plus 12AT7 TS you may get to much of the same sonics, not that it have to be bad, but than again, depends on the rest of you system. I would say, try them both and you will hear the differences directly.

I like Brimar - Very Low Noise & superb dynamics.
I use a quad of 12AX7's in my mc phono stage & they can't be beat.