Jim-on your spec page for the SS 9.5 speaker you list a recommended amplification of 150 watts to drive the speakers. The McGary SA2 amp is rated at 80 watts. You mention this combination to be a perfect fit. I’m currently driving and enjoying my new SS 9.5 speakers with an ARC VS115 amp rated at 120 watts. I’ve been considering auditioning some more powerful amps to see what the speakers can do, but now I’m confused. Any thoughts?
I mention 150 watts because that is what I used at the time the SS 9.5's came out. These are solid state watts. 120 watts is likely enough if you listen at moderate to moderately high levels. If it starts to sound a bit bright and brittle, chances are you are playing the system loud enough so that the amp clips. If this is the case, a higher power amp will provide more headroom.
Keep in mind that each doubling of halving of amplifier power is roughly equivalent to a 3db difference in output. So if you move from a 150 watt amp to a 300 watt amp, you would basically get about 3db of additional headroom.
Tube amps don't clip hard like solid state amps do. They just act more like limiters/compressors if you drive them too hard. As you continue to increase the volume, they simply don't play any louder. But they don't get brittle sounding. So you can get by with far less wattage. At the California Audio Show, we used Mike McGary's SA1, rated at 30 watts, to drive a pair of SS 9.5's. We never had a problem. So his SA2 amp, rated at 80 watts, would be more than enough.
The deeper a speaker plays, the more power is required to move more air down low. Solid State amps tend to control woofers a bit better than tube amplifiers. But tube amps have that liquid-smooth midrange that tube lovers desire. So there is a bit of a trade-off there.
I just found that Mike's SA2 amp sounds marvelous with the SS 9.5's. So that is my current dream combination.
I hope this helps.