Tube Amp Noise with Klipsch Cornwall II

Sell Rogue.
As previous posters mentioned, your vintage Klipsch will pick up virtually any minor oscillations of the amp.
Technically I would experiment with adjusting feedback (obviously lowering the gain factor which may significantly help avoiding noise) along with adjusting bias current to the specified level of the THD which is more like re-tuning the amplifier.

Magfan,
Adjusting a gain very often is a feature of amplifier without any kind of re-dedign. It's rather 'adding' to an existing functionality and making the unit less-depended on tube quality. Most-likely, if higher quality tubes are purchased at the more than half-price the amp worth, the noise may still be an issue.
Tube amps are flexible in general in terms of adjusting a gain and/or lowering input sensitivity. The pot you need to install instead of feedback resistor to figure out the value at which the noise dissapears. Adjusting bias may or maynot be necessary neither on small signal or power tubes.