high power tube amps vs ss

Distortion or not, high volume levels if overdone will damage your ears . Unfortunately many musicians(this includes classical un amplified genre also) suffer significant hearing loss over the years due to excessive SPL environments. Be careful and preserve your precious hearing sense.
Regards,

My old XA100.5 monoblocks ( 100 watt classA) were superior in drive, control, slamm and dynamics compared to my older heavy Modified Musical Fidelity Nu-Vista-300. This one measured far over 2 times 350 watts ( 8 ohm)

I naturally, and I bet I'm not the only one, tend to turn up the volume until I perceive the "sweet spot". Since odd ordered harmonics are our sound pressure clue, their absence (relative term), with very clean reproduction will tend to promote increased listening levels. It does not sound loud even though it is. My solution, since I listen several hours daily, is to use a sound meter to monitor spls. I'm using a free droid app. Sometimes I even pay attention to it.

Since I have set up my system to be absent of loudness cues, it frees me to set the volume to the level that seems appropriate for what I am listening to. A solo guitar being quieter than a full orchestra for example.

For example, do the harmonic loudness artifacts you describe commonly fall into the frequency ranges depicted that ears are most sensitive to?

The answer to this question is usually 'yes'. The reason is that the amplifier has to work harder to reproduce the lower frequencies. Their harmonics will often show up in the 'birdsong' region.

I can provide a simple test that shows how important this odd ordered thing really is. It can be done with simple equipment and is quantifiable. I've offered it before. If anyone here is interested, just say so.

Thanks Jake. I think the impedance/phased angle plots are demanding as reported in Stereophile mainly because of the 2 ohm dip and 4-5 ohm range. But other than that, the impedance is quite flat between 4 and 5 ohms across the freq. band. The low bass peaks are typical. Nevertheless, it does demonstrate the VS-115's impressive performance capability. How many amps out there can push power into such low impedance loads??