When an amp puts out 90 watts....

Do NOT share that with your therapist.

Not only is consistent power output typical of tube amps, but also McIntosh amps that use autoformers have a stable power into all impedences.

Not meaning to hijack my own thread but since Mjcmt brings up McIntosh and autoformers, I bought some Speltz speaker cables and an IC from him some years ago. I recall he was also offering something called a Zero Box.

I'll go and search on this topic and see what I can find, but does anyone have any comments on Speltz's Zero Box and under what circumstances using them might be of benefit. Again, I am unhappy with my current speakers: I don't know if it is the amp or the room, or I just don't like the speakers but I do think there might be a mismatch in my system.

System:
Speakers: PBN Montana XP
Ampilifer: Butler Audio 5150 (currently in use in 2-channel mode only)
Pre-amp: Lector Zoe
Source: Raysonic CD-128

"Again, I am unhappy with my current speakers: I don't know if it is the amp or the room, or I just don't like the speakers but I do think there might be a mismatch in my system."

What is it that you don't like about your system and what do you expect from an upgrade?

Fin,
I think that is indicative of sn amp with higher output impedance, usually but not always an attribute of tube amps. An amp like that will probably perform best into higher impedance speakers, ie 16ohms, which is not common. Its a special breed that needs a special mate. My recollection is that pbn is probablyof the more typical ilk, impedance of 8 ohms or less. Probably not the ideal pairing, but workable.