Tubes to Watts Ratio

Mike,

Not sure because the manual doesn't specify and I cannot seem to find much info on line. My guess is UL, as these were made circa mid 90s when triode wasn't fashionable. On the other hand, they are very midrangey and sound like what I think a triode amp might sound like.

There are a variety of factors that govern the size of transformers. In power transformers, temperature rise can be a big factor- transformers that don't get as hot tend to be larger.

In output transformers, the amount of bandwidth that the transformer has on the low end has an effect on the size, as does the power that the transformer can deliver. If the transformer is set up in a class A amplifier, it might be a bit larger as well.

This is all general...YMMV

Swampwalker, Do you mean to say Mike Sanders has marketing people rating the power output of his amplifiers?

I think its the design choice also.Sometimes,tubes sound better being pushed hard,other times,the opposite.If I didn't need the extra power,I'd lean toward the cooler,lower wattage one,if it sounded the same.I think four EL34's would give abound 30 watts in triode.Cary has some amps that put a lot of watts out for a tube type in one amp,the opposite in one of the other amps,from the same company.

I am sure that Rodger Modjeski (sp?) of RAM tubes and RM amps fame can give you an idea. Some of his amps seem to produce very few watts per tube while other an astonishing number of watts per tube. I think there are some SS in the cascode of amplification in some of his amps. I think ARC uses SS as well beyond simple rectification duties, but I am not entirely sure.
I own a Jadis DA 60 with enormous heavy trannys it weighs 80 Lbs. It's rated power is 60 wpc from 4 KT-88s. It does run in class A I am told which may account for the relatively low nuumber. In practice I use it to drive speakers that are 87Db sensitive and I never run out of power. So I am convinced that it can make more power "peak" than 60 watts.
I also own monoblocks that have 4 X 6CA7s each. These are just as heavy @ 78lbs. These however with less "plate dissipation" per tube are rated at 75-80 watts per side. The big difference may be that It runs in Parallel PP.