Sounds a lot like a tube to me. Easiest way to check is to simply swap the present tubes, in pairs (though I assume there'll only be one pair on the phono stage...?), between the two channels. If the noise moves between the channels with the tube, then there's your culprit. Most tubes will have some level of "tube rush" (much like the pink noise your talking about). But if it's loud enough to bother you, then it's definitely not one you want to keep.
Bad tube?
I just bought my first piece of tube audio equipment, an all original HH Scott 299. I'm a bit green when it comes to tubes so I'm asking for a bit of help. When I'm using the turntable I get this noise out of one channel that's almost like pink noise, but at a very very low level. It doesn't appear when I listen to the two line level inputs. Could it be a bad tube in the phono section? Or could it possibly be a result of the way the Regas ground their cable in the plug? It should probably not go without mention that since the Scott is original it has an original, un-grounded power cord.