Hello Simon,
I am using a Denon 103R (0.25mV). My Chenin was set to Low gain. The phono section currently have the Mullard M8080 and Siemens 6922. I have plenty of gain! The phono gain knobs(pair) are just 1/3 setting and I can get 89 to 90 dB SPL with the linestage volume control to almost half. That is a lot! I have no tube rush or hum. I can put the phono knobs at max (both) and linestage max and cannot hear the hiss (all tubes does you are right) at about 4 feet away from a 90-91 dB sensitivity midrange driver actively driven of my Orions. If I placed my ear next to the speakers, yes there's some tube rush but no hum. That's it.
I think, its either you have a very noisy phono tubes or the FET input is out of whack. Just my opinion of course.
Goodluck
I am using a Denon 103R (0.25mV). My Chenin was set to Low gain. The phono section currently have the Mullard M8080 and Siemens 6922. I have plenty of gain! The phono gain knobs(pair) are just 1/3 setting and I can get 89 to 90 dB SPL with the linestage volume control to almost half. That is a lot! I have no tube rush or hum. I can put the phono knobs at max (both) and linestage max and cannot hear the hiss (all tubes does you are right) at about 4 feet away from a 90-91 dB sensitivity midrange driver actively driven of my Orions. If I placed my ear next to the speakers, yes there's some tube rush but no hum. That's it.
I think, its either you have a very noisy phono tubes or the FET input is out of whack. Just my opinion of course.
Goodluck