Guess I owned the wrong speakers (hell, the wrong system) to go with my Seventy...enjoy your 'new' system! ;^)
Seriously, I still find it impossible to beleive that the amp I knew could make sound to draw such raves - *unless* something was wrong with mine unbeknownst to me (it certainly didn't seem so ; the sound seemed about appropriate to what the amp was [better than the NAD it replaced], it looked beautiful inside, and it never gave me a lick of trouble otherwise), *and* we accept the notion that a properly-functioning Seventy *really is* capable of top-rank sound with no excuses (a proposition I would find dubious even if I had never owned one, being as there's no apparent reason for suspecting it to be true). System synergy can trump a lot of things in some areas, such as tonal balance or soundstaging, but IMO it's tough to give a lot of credence to the implication that system synergy could grant superior resolution, purity, imaging, or harmonic structure (as examples of other areas where I thought the Seventy wasn't strongest) to a group of components whose weaker links are known to fall short in those respects when heard in other contexts. And especially when the partnering speaker in question should be stressing the amp much more than the Thiel CS2.2's I used mine with (a pretty kind 4 ohm load of average sensitivity, and not a speaker reputed to wildly prefer the tubes which beat out my Seventy).
I'm curious: Was your independent opinion of the audition combo quite as high as your prospective buyers'? Does the Seventy beat out your own reference amp(s) in this application? If you leave the speakers and amp set up as is but swap out 'better' wires and sources, does the sound not improve? The only scenario I can think of here is that the amp/speaker cable/speaker combination, taken as a sub-system, represents a fortuitously copacetic mixture of electrical properties, that the front-end balance perfectly complements that of the back-end, and that you have the speakers perfectly set up in a room nearly ideal for them. Either that, or your customers can't hear. Or the Seventy, against all odds and reason, is one of the very greatest amps ever made...
Seriously, I still find it impossible to beleive that the amp I knew could make sound to draw such raves - *unless* something was wrong with mine unbeknownst to me (it certainly didn't seem so ; the sound seemed about appropriate to what the amp was [better than the NAD it replaced], it looked beautiful inside, and it never gave me a lick of trouble otherwise), *and* we accept the notion that a properly-functioning Seventy *really is* capable of top-rank sound with no excuses (a proposition I would find dubious even if I had never owned one, being as there's no apparent reason for suspecting it to be true). System synergy can trump a lot of things in some areas, such as tonal balance or soundstaging, but IMO it's tough to give a lot of credence to the implication that system synergy could grant superior resolution, purity, imaging, or harmonic structure (as examples of other areas where I thought the Seventy wasn't strongest) to a group of components whose weaker links are known to fall short in those respects when heard in other contexts. And especially when the partnering speaker in question should be stressing the amp much more than the Thiel CS2.2's I used mine with (a pretty kind 4 ohm load of average sensitivity, and not a speaker reputed to wildly prefer the tubes which beat out my Seventy).
I'm curious: Was your independent opinion of the audition combo quite as high as your prospective buyers'? Does the Seventy beat out your own reference amp(s) in this application? If you leave the speakers and amp set up as is but swap out 'better' wires and sources, does the sound not improve? The only scenario I can think of here is that the amp/speaker cable/speaker combination, taken as a sub-system, represents a fortuitously copacetic mixture of electrical properties, that the front-end balance perfectly complements that of the back-end, and that you have the speakers perfectly set up in a room nearly ideal for them. Either that, or your customers can't hear. Or the Seventy, against all odds and reason, is one of the very greatest amps ever made...