noisy tube preamp


I'm fairly new to tubes but have recently acquired a tube preamp. I'm really liking the air and the soundstage it provides, something the solid state stuff haven't done as well but the one issue I have is the elevated noise floor. It's really only audible when no signal from the source is being played, like when the system is simply on or when the song stops. Also there is an occasional quiet, short lived buzz from the speakers that pretty much goes away after the preamp warms up and lastly, after the unit has been on for several hours, like 24+ it will start to emit a high frequency pitch that also is only audible with no music playing but it is louder than the inherent noise floor of the pre. My question is, is this something I can remedy by rolling tubes or is it something that has to do with the pre itself like the design or a failing part? Btw, it's a jolida fusion preamp.
lukaszwk
@lukaszwk,

You might get better help if you disclosed what preamp.

Sounds like it might need new tubes.
@atmasphere Huh... That did not occur to me. I kind thought of the preamp/tube as a single entity especially when new but I see how that could be misleading.
Make sure tube pins are cleaned  and tubes  of high quality .vintage Matched pair New old stock are best lowest distortion.  If that doesnot lower noise to not be audible unless ear us up to the speaker Then your preamp either have problems needing to be fixed or is of Lesser quality and poorly designed.  My tube amp is Trans former based and Very quiet. with tube preamps quality is even  more important then with solid state  ,but when done correctly  the soundstaging and 3 dimension realism aspects it brings no Solid state preamp cannot quite match.
Upscale Audio for a tube overhaul.  Good information on the website.  Probably will fix the whole thing.  Enjoy.