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.
fruff1976
You should read this 10Audio review:

http://www.10audio.com/rogue_metis.htm

Particularly noteworthy:

"Downsides? A few. The Rogue is loud. There's much more spurious noise through my 89 db sensitive Soliloquy 6.2s than I'd like, and not just tube rush. I did have some issues with hum as well. Listen carefully and you can hear this from your chair at around ten feet."
I'd say hum and hiss + buzzing. It's just noise which can be heard in the room when the unit is turned on. About 20 seconds after you turn it on the buzzing/hissing/humming starts.
UPDATE: when I switch out to my old preamp the same type of noise is still there, just much quieter. You can hear it maybe up to 1ft. away from the speaker. It seems as if this amp is just accentuating the noise to an obnoxious degree.
Dumb question- Is the noise only present when you rotate the volume control to its maximum position? Is it quiet when the volume control is in a position when the music is at a 'normal level' or even a bit loud?

If the answer to these questions you are just talking about your units noise floor or the noise from the (in your case) connected CDP. The fact that you do not hear anything for 20 seconds indicates that the 'hum' comes from your pre-amp (or source) which is muted on initial turn on to avoid transients while your pre-amp is stabilizing.

Try disconnecting the CDP and see if the noise level changes. If not then its the pre-amp. If you hear the hum/buzz etc at normal volume levels at 10 feet you've got a bummer and should contact Rogue for repair or replacement.