How do Digital Amps Mfrs. compare in sound?

Look to the technology the amps are based on. ICE, Tripath, UcD, etc. I have used both Tripath and UcD based amps and I think UcD is better. Either amp is better than most mosfet,jfet, solid state amps. They have no "sound". They will, without adding their own sonic signature, amplify what they are fed. They are "neutral", which is what you want an amp to be. I have stated many times a tube pre with a "class D" amp is a great combination. I also believe any SS amp sounds better with a tube pre. I only know, that for me, "Class D" opens up the sound, highly detailed, very wide sound stage and with the tube pre, produces a warm musical experience. I have been in "hi fi" since 1971. The debate over this new technology has been anything but stifled. Just as SS rose against tubes, cd's replaced cassettes which came out against records; chips will overshadow mosfet/jfets. Each camp will have its champions and shrill voices. There will be product for each technology. Most will go with the new technology, some never will.
Excuse me as I listen to some Bach, produced by my system of cd through tube pre to a "Class D" amp. Debating over technology is not what is important, listening to music is. Less chat, more tunes.

I have a NuForce integrated I purchased used here on the Gon. It definitely had a nasty glare on top. I sent it in to NuForce (xlnt service) for a V2 upgrade - glare is all gone and it is a very sweet unit with great dynamics - and I only use it with digital sources.

The gentleman I bought it from is, among other skills an equipment reviewer. When we were discussin the upgrade (which was the plan going in) he wrote me that "I think the learning curve is still relatively steep on this kind of stuff which means upgrades not to far out from release (a few years at best) have meaning."

As noted, at least in my experience this has turned out to be true.

I prefer UCD technology as well. I have compared it to Melos MAT-180 and a Karan KA-i180 and prefer the UCD based amp. I use mine with a tubed preamp also.

For those of us a step behind in this debate, which products offer the UCD technology?

I am running the latest and top version of Nuforce, the Reference 9 V2SE. It is very wonderful accross the spectrum, particularly the bass and including the highs. The amp is reported to have high bandwidth, low distortion, near zero phase shift, a very high damping factor and a proprietary modulating signal versus Tri Path etc.

That said I can understand the difference of opinion about these amps. Using a tubed pre (Audio Horizons) my initial sound was amazing in the bass and harsh/glassey in the highs on 2/3 of CD's, noticeable at higher volumes in a very live room. I replaced my silver IC with gold and used Hyperion vibration control discs under the amps and voila! the highs are now sweet, extended and yet tame at high volume on about 80% of CD's. So the amps are sensitive to source material, wire, FRI, EMI, and vibration. They are also psychologically challenging. You hear this incredible extended articulate full bass and look down at the puny little things, knowing you paid less than half what would be usual for this good a sound, and it doesn't add up. But it is worth giving these amps a try. The detail, soundstage and musicality can be amazing if some time is spent on set up. Added to that is portability, low energy use, and space savings.