I've driven myself batty chasing down the same gremlins in the past. I DO know that basing your noise level "frame of reference" on what you hear when your pre-amp is set to "CD" when comparing phono noise levels is a recipe for total frustration. The fact that you are dealing with the low-level phono signal, AND have tubes in the circuit almost demands you learn to tune out some low-level noise as you do with vinyl surface noice and just "enjoy the music", as they say. Want to really frustrate yourself, though? Add a step up transformer to the mix, and then spend hours trying to find the position where it causes the least amount of added 'hum'. AAArrrgh!
My latest OCD phono fixation? The motor noise I can hear from my 'table between tracks in a quiet room. Can I hear it when the music is playing? Of course not. Does that stop me from obsessing over how to get rid of it? No way, Jose' - just the idea that it's there really bothers me.
Audiophilia nervosa.
I do look forward to the responses from some of the other, more knowledgable A-goners to the good question you've posed, and good luck.
My latest OCD phono fixation? The motor noise I can hear from my 'table between tracks in a quiet room. Can I hear it when the music is playing? Of course not. Does that stop me from obsessing over how to get rid of it? No way, Jose' - just the idea that it's there really bothers me.
Audiophilia nervosa.
I do look forward to the responses from some of the other, more knowledgable A-goners to the good question you've posed, and good luck.