CRTs are susceptible to external magnetic fields. Using your proposed setup, the transformers in your amp may be close enough for stray magnetic fields to affect a CRT TV. It's hard to say, since it depends on the amp's power and circuit layout - the locations of the transformers relative to the location of the CRT is crucial.
LCD, Plasma, LCOS, and DLP sets are not susceptible to magnetic interference.
BTW, I'd also worry about heat buildup when installing a tube amp inside a closed cabinet.
LCD, Plasma, LCOS, and DLP sets are not susceptible to magnetic interference.
BTW, I'd also worry about heat buildup when installing a tube amp inside a closed cabinet.