Tzh21y, do you know how to read schematics? I'm guessing you don't, because if you can make a statement like "I don't care what the schematic says" etc., then you'll never understand that there is a cause-effect relationship behind ALL audio experiences. Whether a person prefers one kind of sonic experience over another is their call! But that doesn't change the science.
I've used all kinds of 12AX7A/5751 tubes in the MC275 V-1 slot while driving the amp in BAL mode; and they don't have ANY effect on the sound; a result which understanding the schmatics would make clear for you; unless of course you subscribe to 'audio voodoo' ;--) And if you are in fact being sincere and objective (and good manners demands I assume you are ;--), the only explanation I can offer for your "experiences" it that you've got some 12AX7's with badly damaged filaments, gas or perhaps shorts!
Further, it's been my experience that when a listener says they sonically prefer SE operation over BAL operation, it's because;
1.) Some other hardware in their system is skewing the result for reasons contained in that hardware.
2.) Or the quiet and more accurate BAL operation is revealing some nasty condition or component elsewhere in the system that the less precise and less dynamic ("natural sound"?) of SE mode is masking.
My point here, is that instead of throwing up one's hands and pronouncing that the Gods of Science and Audio somehow or other work differently in THEIR listening room, it would be far more instructive (and productive of better sound) to learn some of the science behind the things we hear (both good and bad) and not just chalk it up to the weather or the color of the listening room ;--) I've looked at your system and would be happy to discuss these things in greater detail if you want to send me an email.
Neil
.
I've used all kinds of 12AX7A/5751 tubes in the MC275 V-1 slot while driving the amp in BAL mode; and they don't have ANY effect on the sound; a result which understanding the schmatics would make clear for you; unless of course you subscribe to 'audio voodoo' ;--) And if you are in fact being sincere and objective (and good manners demands I assume you are ;--), the only explanation I can offer for your "experiences" it that you've got some 12AX7's with badly damaged filaments, gas or perhaps shorts!
Further, it's been my experience that when a listener says they sonically prefer SE operation over BAL operation, it's because;
1.) Some other hardware in their system is skewing the result for reasons contained in that hardware.
2.) Or the quiet and more accurate BAL operation is revealing some nasty condition or component elsewhere in the system that the less precise and less dynamic ("natural sound"?) of SE mode is masking.
My point here, is that instead of throwing up one's hands and pronouncing that the Gods of Science and Audio somehow or other work differently in THEIR listening room, it would be far more instructive (and productive of better sound) to learn some of the science behind the things we hear (both good and bad) and not just chalk it up to the weather or the color of the listening room ;--) I've looked at your system and would be happy to discuss these things in greater detail if you want to send me an email.
Neil
.