Lowering Tube power amp output

Call Rogue audio!! The only audio amps I know of that you can remove some power tubes reduce output power without issue or damage is Atma-Sphere amps.

Mike

probably off my rocker here,  "but"

i sometime mess around with some older(50's/60's) lower power tube pcs, and when first start up i always start with a variac. slow, low power. i started to realize that most all tube amps will generate sounds at a lower power. some actually start to generate music at 70/75 volts,(not a perfect sound) but good enough to tell that the unit was going to work without the magic smoke . i realized that around 100vac the beginning sound was good enough to sound ok for my old snuff box ears(older folks might get this) also actually drops transformer temperature, and i feel with less trans stress. oh, less heat by far. with a pair 6l6 amps, 50w quad each running at 100v did make a lot of difference in room temp. but still these are my winter amps, they will come down in the spring. 

you can hang me if i am wrong. so far it has worked for me. my opinion less power in, cooler internal parts, maybe even longer tube life, a lot less heat. i have been doing this for a few years with no noticeable difference in sound quality (snuff box/can) 

by the way usually i don't push the amps very hard, most time at lower volumes.

16x16 room, between 85 / 100db as loud as i like it, until after a little numbing then sometime move volume up a little. that is a lot of talking too much but(lucy said splain yourself).

sorry for being long winded  

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?

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.

@tubelvr1 The more powerful you make a tube amp (unless its an OTL) the more limited its bandwidth becomes, due to the output transformer.

What this means is that for the most part smaller tube amps sound better (except for OTLs where bigger ones sound better).

So rather than remove tubes to reduce power getting a smaller amp is good advice. FWIW the output transformer is designed to provide a certain load for the power tubes provided its output is loaded correctly (for example an 8Ohm speaker is connected to the 8Ohm taps). When you remove tubes that load that the transformer provides will change and so the remaining tubes won't be loaded correctly and most likely will be too low of a load for the remaining tubes. This will lead to excess distortion, the tubes running hotter and their reliability compromised.

So don't do it!!