Are you saying there becomes a point in time, when buying more and more expensive SS amps, where it's pointless because SS amps are too bright and will cause listening fatigue and a tube amp won't?
In other words, a $1000 SS amp isn't useful but a $1000 tube amp would be useful at the same price-point?
That's his take but hold off on taking his feedback as the only perspective on it.
First off, I don't find SS amps being too bright; in fact, I find too many tube amps to be too dark and the notes too smoothed out. At the same time, I have encountered a lot of SS circuits (amps and sources) that sound too soft, just like what we associate with tubes. An example of an SS circuit that sounds like a tube which I didn't like was the Rega Apollo - the treble was too smoothed out that I can barely hear the cymbals vibrating, and there's a bump in the midrange region that made some voices sound like the singers had a cold (it sounds worse than my Aurisonics ASG-1, which has nothing audible above 16khz). I also encountered circuits that used tubes but I liked them a lot better than this - like Cayin's products. The CD50T sounds even, smooth, and the midrange is only slightly "sweeter," but nothing like singing while pinching your nose holes; the CDT23 has a powerful sound that sounds very "live," and some dismiss it for being too bright but there's nothing like hearing
Fanstasmic on it, while Norah Jones' voice is nicely extended in the treble. Both were with my Cantate.2 amp and HD600. Cayin's amps were also used while I was in that shop (the whole afternoon actually) and I didn't hear anything immediately unnatural about the tone, and the A88 was powerful enough to rein in some Aurum Cantus floorstanders.
Second, if anything, some cheap SS amps with weak power supplies have a tendency to sound shrill and thin, likely because the power supply can't supply current when the impedance swings on louder, lower frequency notes when you have a lot of other instruments playing already. On the flipside, a poorly-designed tube amp will have the tendency to make it seem like someone's got the vocalist's nose while they were singing and they aren't about to let go of that nose. Maybe even try to twist it off.
Third, nowadays it's actually hard to find SS amps and sources that are shrill-sounding. Sadly, that's not always because they have better designs, but because companies know that people like buttery creamy warm sound to the point of someone's got the vocalist's nose and might twist it off, they deliberately design the circuit (mostly the op-amps) to sound warm, maybe with a bump in the midbass also. Of late the only noticeably shrill sources I've listened to are DVD players (sometimes you get desperate when your CDP's broken), and to a much lesser extent, the NAD C515, the iPad2 (not really a problem in my case because the IEM I use with it is a bit too warm; also, I wouldn't know about other iPads since this is what I have), and my MSI Z77 motherboard. Even my laptop only has shrill treble if I play it too loud, so it's likely a distortion characteristic instead of a not flat response outright.
Fourth, when SS amps are observed to be bright, one has to ask what other gear was in that system - specifically, what source and headphone? If you have an amp that only does what it should do by definition - that is, to
amplify an input signal into one that can drive a given speaker or headphone - then basically it is allowing the source to shine through more, or at least as much as the headphone or speaker would allow. I've tried my Cantate.2 with a variety of sources and the changes in overall sound of the system is more audible with it than with the Little Dot MkII and a CMOY I had before, for example (the latter two were too warm with everything), and I've heard a Rega Apollo squeezing nasal cavities while a Cayin CD50T was just the right amount of different over the USB DAC - that is, nothing unnatural outright, but the midrange is a little sweeter and the placement of instruments was clearer.
Fifth, for all we know my ears could be losing response/sensitivity at high frequencies as I'm approaching thirty. Just to balance that out theory however, even younger me never dated anyone with a shrill voice, although the real reason isn't solely that I wouldn't be able to talk to someone like Kristin Chenowith without flinching, but that I'm more likely to date someone with Kathleen Turner's vices (all my exes smoked and drank copious amounts of tea or coffee) and her voice. Or Bonnie Tyler's defiance of medical advice (sums up my exes) and her scratchy voice too (or at least so around finals week, or the bar exam). So basically as much as my ears' health might be suspect, I also have a history of finding nearly any female voice too shrill it's a wonder I have cats instead of dogs (and I have to talk to them in a cartoon voice because my normal booming voice is scary to them).
