pre-amp unacceptable noise level?

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.

The noise is the same level whether the volume is up or down. It's independent of the volume level. The problem is during softer passages or listening at lower volumes the noises/buzz/humm/hiss whatever it is can be heard over the music. It can be heard even when the cdp is turned off and no music is playing.

You may want to try different tubes as suggested by others.

The dealer was very cooperative along with Rogue and a new one is being sent. Rogue customer service along with the dealer has been outstanding so far.