Mapman,
I'm using a lower cost class D amp ($630 ClassD Audio SDS440sc stereo amp rated at 440 watts@4ohms) than you are using but I still notice the same attributes that you described.
When I turn up the volume the sound retains it's balance and there is no compression, clipping or tonal changes. The music just gets louder while exhibiting an effortless quality.
But, what's even more interesting and impressive to me, is that it has this character when turning the volume down, as well. I enjoy this amp, whether with music or ht, much more than my previous amp (Aragon4004 that had similar power but was a class A/B type). I never heard, or at least noticed, any other amplifier type that has such good performance at both low and high volume levels.
Atmasphere,
I am definitely not implying that tube amplification is obsolete. Class D amps, imho, do not sound the same as good tubed amps. There will probably always be users that continue to prefer the virtues of good tube sound, myself included. I've achieved some of the tube sound I prefer by combining a tubed preamp in front of the class D amp.
Class D is so neutral, quiet and clean that I'm probably hearing the sound of my preamp and source more than the sound imparted by my amp. I have noticed an improvovent in sound (more tube like) with the VTL/ClassD Audio combo than my previous VTL/Aragon combo. This was further improved when I recently replaced my preamp's NOS Mullards with a fresh set.
Lastly, I just want to mention the improved bass performance of class D in the bass area of my system's performance. The Aragon had good bass with my inefficient Magnepan 2.7qr spkrs. But I felt the need for more bass and added a subwoofer crossed over at 45hz. When I substituted the CDA for the Aragon, I immediately noticed a slight overemphasis in the low bass region. I turned down the sub's high cut flter down from 45hz to 35 hz and this corrected the issue. I think the class D amp's high Damping Factor (in the thousnds) was the cause of this.
This little CDA amp took control of my spkr's woofer panels like the Aragon was never able to, even though it's 1/3rd the size, weight and price of the Aragon. There wasn't just more bass, the bass was tauter, more textured and more nuanced. I confirmed this by turning my sub off for a few days and didn't really miss it that much. I would loved to have used, or at least tried, a tube amp but my spkrs need too much power to use for both music and ht.
I would think the traditional high end solid-state companies should be more concerned with the improvements in class D technology than the traditional high end tube companies. This is probably reflected in the number of ss companies vs tube companies offering class D amps. On the ss side, Mark Levinson, Rowland, Bel Canto(started as a tube amp maker yrs ago) and, I believe, Cary all have introduced class D amps. The only tube company I'm aware of that currently offers class D amps is ARC. I'm sure others know of a few more on both sides. I was just reading that PS Audio is about to introduce a new class D amp this year, too.
As Mapman and others have pointed out on previous threads, there are a slew of new companies that are just beginning their journeys to possibly becoming traditional high end companies utilizing the new class D technology; W4S, Merrill Audio, Mola-Mola, Acoustic Imagery, PS Audio, etc.
I'm sure there will be more companies jumping on the bandwagon.
IMHO, class D just has too much going for it (good and improving sound quality, small size and weight, very efficient, very powerful, relatively low cost, cool running, neutral sound character) for it not to be the wave of the future. I really do hope you decide to jump on this juggernaut bandwagon while there's still some room on it.
Best wishes,
Tim
