What 12ax7 tube brand is this?

[larryderouin]

I was thinking of the 5751's for the AUX/Line in stage, so I guess, that is a preamp but not a phono preamp/stage. But good to know anyhow. Yes, it would seem to me that the faint signal coming from the cartridge would suffer a bit from a lower gain tube like a 5751.

Exactly. This is why Gadget and I advised against the 5751. It's not much, but you need all the help you can get. The gain stages are optimized for the 12ax7. Imagine what you'd get with a 12au7 in there with a mu of 30!?!??!!! Not a whole lot of anything.

Getting back to the tubes........
The 7025's are ruggedized 12ax7's. If I had the $$ and the choices, I'd take the 7025's and the B.B.'s Put the 7025's in the Hi-Lo-Filter positions, and the B.B.'s in the Phase Inverters. Listen and then swap them. Listen again using the same source and track. Leave them in whichever position you like best. Keep the GE's for the MPX.

Because V14 and V15(Low and Hi Filter Amp's) both work the LEFT and RIGHT Channels they need to have their sections matched as close as possible. The phono tubes should be section matched. The P.I. tubes aren't that critical as each works one channel for driver and phase inverter.

So make sure the tubes at least have their sections matched. Matching the sections will ensure that there are minimal SPL imbalances caused by the tubes.

 

[davstev]

Pardon my ignorance but which are the BB's?

 

[gadget73]

Amperex Bugle Boy I'm guessing.

 

[arts]

Does that dealer start with RAD-- HOV---?

Yep, I know....besides being unscrupulous, he is also really unpleasant to deal with, so easy to avoid.

My dealer is in Toronto, Ring Music. Top notch.

Thanks for the tip!

Give the man a cigar!