pre-amp unacceptable noise level?

How much is an unacceptable level of noise/humming etc. from a pre-amp? I just bought a new tube pre-amp and when I replaced my old solid state one with it the noise level from the speakers practically tripled. There is an audible humming from the listening chair 10ft. away. I can't say I'm particularly happy with this considering the one I replaced did not do this.
Sounds like you have a ground loop hum. This article should help you troubleshoot the problem.

Another cause of humming can be from locating a pre-amp too close to a power source, usually an amp on which some people like to stack stuff (ever noticed how many high end pre-amps come with seperate power supplies often connected to the pre-amp by a long cable), and proper cable dressing, that is, making sure all of your IC's are not near any power sources or power conditioners. I've had problems with both of those issues. Easy to cure. BTW this is generic advise - I've never owned a Rogue.
My Rowland 102 amp introduced a major hum into my setup. Turned out to be the cable TV. A Jensen Ground Loop Isolator fixed me right up.
I don't have t.v. hooked up into it. It's just a 2 channel rig with a cd player and I haven't hooked up my turntable yet.