@cal3713 Yes, it is interesting idea. Not only for the possible upgrade, but also in case of power element failure. Performing musicians enjoy ease of tube change in comparison to power transistor replacement. The only negative I can see is the longer connection that might radiate electrical noise (become an antenna).
The main rule in any switching design, like SMPS, is to keep connections as short as possible.
The main rule in any switching design, like SMPS, is to keep connections as short as possible.