Plato,
Since you are now picking up on the phono surface noise, have you considered switching out your phono cartridge?
Some cartridges pick up more surface noise than others.
Some cartridges, like the Koetsu's, Transfiguration, etc.. are dead quiet.
Some cartridges like the Shelter's pick up a little more, but are still pretty quiet.
Some like the Benz Micro Glider pick up still more. Not bad mind you, but more than the other two.
(You did not list what cartridge you are using, so I listed the few that I have personal knowledge of.)
Just a thought. Good Luck in your search!
Since you are now picking up on the phono surface noise, have you considered switching out your phono cartridge?
Some cartridges pick up more surface noise than others.
Some cartridges, like the Koetsu's, Transfiguration, etc.. are dead quiet.
Some cartridges like the Shelter's pick up a little more, but are still pretty quiet.
Some like the Benz Micro Glider pick up still more. Not bad mind you, but more than the other two.
(You did not list what cartridge you are using, so I listed the few that I have personal knowledge of.)
Just a thought. Good Luck in your search!