Shuguang 845B vs Shuguang 845M

That's funny, Jeff. I have the Gallo Ref 3s and much prefer the metal plate "C" 845s to my 845Bs because, among other things, the Bs are a touch too warm :-)

Just to further confuse the nomenclature issue, I'm using 845s from Sophia Electric, but they're the 845C, not 845M. I thought the "M" was proprietary to SuperTNT. In any event I like the 845Cs well enough that I recently bought TWO new pairs when one of my old ones bit the dust. I'm not good at describing sound, but these are the most musical 845s I've ever had in my amps. Good luck, Dave

PS The only downside is that some of the 845Cs fit so tightly into my tube sockets that they're very difficult to remove.

Jeff, I would guess that having an active preamp (in my case, CJ Premier 17LS2) in the system would indeed make the difference, I've tried eliminating the linestage at various times, always went back to one because the "direct" route sounded too threadbare to me. Obviously YMMV. Dave