Tube Lab  

Great question! Well first off at 85db you are just below average speaker sensitivity, so not great, but not bad either. If i owned those speakers I'd be taking them apart and modding them like crazy, so it's probably a good thing i don't have a pair! The manufacturer specifically says the minimum power is 30w and the R8 in Triode mode puts out 25w and in ultrlinear 40/44w depending on power tubes used. I wouldn't be too worried running in triode mode at moderate listening volumes (not loud). What is important, is to get the impedance matched correctly (8 ohms tbc). Tube amps will soft clip when driven hard (you probably won't even know it) before they hard clip. What is always in danger is your tweeters, they don't like a hard clip and will often decide they don't like living at your place anymore and would rather hang at the dump instead! So i think you are good and if you have a party planned stay in ultrlinear mode and put your wife in charge of the volume!

Yes, remember the signal needs to pass through every tube in circuit, so yes it would and does make a difference. The distortion I was talking about, in a well designed Class AB amp is low, it's not something you would hear, unless you did some careful AB comparisons between a similar Class A and AB amp. But it is a major part of the sonic signature of a class AB amp - it's unavoidable. And of course each design topology has it's plusses and minuses. Good question!