Lowering Tube power amp output

Personally, I would sell the amp and look for a lower powered amp if you determine that you really don't need that much power.  Two hundred watts is usually way more than one really needs for almost any speaker.  I generally don't like the sound of higher powered tube amps that are running a multitude of high-powered tubes, like KT88, KT120, and KT150.  These types of amps tend to be "hard" or "harsh" sounding compared to lower powered amps running the likes of 6L6 or KT66 tubes.  I would take a 40 watt KT66 or an even smaller 6L6 amp any day over a high-powered tube brute.

Lowering voltage might do the trick without causing any damage.  In some applications, under-voltage could be harmful to transistors, but, I doubt that there is a problem with tube gear.  Does anyone know if the lower voltage might reduce the cathode/heater emissions to the point where cathode stripping might occur?