Hey Peter- I think they must be running in Pentode if he's getting 100 watts per pair out of them. If you want to know more about the design try contacting Mike Sanders through his site. Phone is best, but you can also email. I've found Mike can be pretty brief and to the point in his email answers though. The same two KT88's give his older Silver 90 monos 90 watts per side in Pentode so it's not a far stretch to 100. Don't know how he does it, but it must be in Pentode I'd guess. Of the four Quicksilver pairs I've owned, the Silver 90's were the most punchy and probably the least refined/musical to my ears and for my tastes. Still a nice set of amps and good for rock and symphonic stuff. Depends on what you like to listen to most. The other stuff I've owned of his had a better sense of air and atmosphere and depth, and I'd prefer any of the three better over the Silver 90's. One is SET, one Push/Pull and the third was also triode but using EL34's. If we hook up when you come to Seattle you will get to hear the SET. Looks good for the 14th as I found out we are actually leaving on the 16th. I'll get in touch later tomorrow.
Best,
Marco
Best,
Marco