I had the same question as tls49. I would not expect an amplifier change to affect the bass, as the woofers for the bass are powered by their own amp.
I do sympathize with the cost of tubes, though, especially given your high usage of the system. Going solid state makes sense, and the Parasound is a nice unit, with the DAC being a plus for handling redbook CD over the Sony's built-in DAC. However, if you like the sound of the Rogue, do you have the ability to audition their Sphinx or Pharoh hybrid integrated amps? As solman989 says, the small signal tubes in those amps should last a long time. Downside to that is not improving the DAC over the Sony, which was good in its time but can be bettered these days.
As an aside, that's a lot of use for a "secondary" system!