How do Digital Amps Mfrs. compare in sound?

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.

I agree completely with one thing that Stanwal said:

"I would have a long listening session with any of them before buying"

That is because switching amps -- which in most cases are analog devices and not digital) -- like any other technologies, have a sound that is much more characteristic to a manufacturer or an individual model than to a 'class'. Thus the sound can range from bright and distorted to exceedingly musical, from extremely extended to limited in bandwidth, from 'dry' to harmonically rich and complex, from quite rough to incredibly subtle.

It is worth pointing out that the HiFi Critic article is almost 2 years old and that at least 2 of the amps reviewed there are obsolete and withdrawn. Furthermore, From a logician's point of view, the negative inductive reasoning used by the author to draw his generalized condamnation is essentially flawed. . . there may be close to 100 switching amps on the market today. . . he examined 3 and declared them to be wanting, then glibly proceeds to condemn the whole lot, based on his spectacularly limited observations. On the other hand his guilty virdict -- had been most likely decided 'a priori'.

If the same reviewer were to examine with a completely open mind current production of leading switching amplifiers such as the newest bel canto Ref 1000 Mk.2, JRDG 312, and latest Spectron monos (just to name the very few I am most familiar with)(, he may discover that the art and science of reproducing music is not the sole prerogative of traditional -- and sometimes nostalgic -- technologies.

Returning to the original question, within the very limited scope of my experience, one of the highest values in amplification -- regardless of class and technology -- may be the very moderately priced current crop of Bel Canto monoblock amps: the Ref 500 Mk.2 and the Ref 1000 Mk.2. As for which variant of underlying chip set may be best. . . it is a question for which there is no particularly valid answer. . . to paraphrase and old cliche. . . "Tubes and chips don't make music. . . designers with tubes and chips make music!"

G.