"D" amps, general discussion who's 1 and why?

Tan43, kindly list in detail your system set-up and your friends.

I first became intrigued about Class D after hearing that Von Schweikert and Gallo were using the Spectron Musican II to demo their products at trade shows, with generally better sonic results than many rooms showcasing costlier gear. After reading a few reviews, the Spectron Musician II became my first entry into the low end of the high end, and my results have been very impressive. The first combination of the Spectron and Totem Forest speakers provided one of the fastest, most dynamic and detailed setups I have ever heard, and very, very impressive imaging and soundstage as well. Exactly as advertised in reveiws of the Spectron.

I recently decided to upgrade speakers, which resulted in my taking my CDP and the Spectron to a dealer, where I played it with Sonus Faber Grand Piano Domus and Dynaudio S3.4's. I thought both systems sounded fantastic. To my ear, the Spectron sounded as good as, but different than, the BAT tube amps that had been driving the Dynaudios. Not as warm but faster and more detailed. My impression was that I was hearing more of what had been recorded in the studio with less coloration. Others might disagree or simply subjectively like the other sound. The Spectron ran circles around the Moon Audio integrated that was driving the Sonus in the store. The dealer seemed genuinely impressed.

During my speaker search I also spoke to high end dealer of lines like Audio Physic, Silverline, etc, who confided that he is using the current Spectron Musician II Mk2 SE in his personal system to drive MBL's.

I ended up buying Dali Euphonia MS 4's, so I have now heard my amp with four different sets of speakers, some more revealing than others. I never heard anything approaching a bad match, frankly just different degrees of excellence.

My Musician II is at least two generations old, and the technology has reportedly advanced a great deal in the last couple of years. Listen with your ears and with no preconceived notions. I have nothing against other technologes, and I am not trying to be a cheerleader for Class D. I truly don't understand why anyone would become ideological in this hobby about a certain technology over another.

If you have the time and the gear is available, I encourage you to listen for yourself. If the sound of Class D is as good or better than competing technology, then you can also start to consider that these amps generate literally no heat, that there are no issues of tube life or possible damage or degradation, etc, etc. These are just incidental benefits to a product that, to my ears, has outperformed most everything I have heard in absolute terms, but especially dollar per dollar.

My recent, limited experience with a Class D amp mimics quite closely that reported by several others above.

I bought a bel canto 300 to use in a second system. For fun, I tried it in my main system (Dynaudio S 3.4, Rogue 90 tube amp, Rogue 99 tube pre, Cary 303/300, Acoustic Zen cables). My overall impression was that it really is a very good amp, warm and musical across the board with a remarkable amount of detail in the mids.

After a few days of pretty careful listening, I decided the class D amp gave up depth in the harmonic overtones relative to the tube amp.

I'm not sure if that is standard audiospeak, but it is standard babble among instrument builders. When you strike a note on a guitar (or any resonant object, really), you hear the primary note loudest--the fundamental--but you also generate a series of higher frequencies that reverberate and these provide considerable depth to the sound. Guitars for some types of music (say, flamenco) and built to minimize overtone structure and others (say, for Celtic) and sometimes built to enhance it.

I decided that the bel canto offered a strong fundamental but considerably less overtone structure that the Rogue. Still, the differences were slight and I still like the amp a lot (and love that's it's "green"). But if you're after complex overtones, it might not be ideal.

I do appreciate the my 300 is not bel canto's best, and I suspect some more expensive designs or different implementations may be quite different.

Info on overtones: http://en.wikipedia.org/wiki/Overtone

Dev, I've heard the Spectrons and the new Bel Canto and think that they deserve serious consideration. I'm feeling no need to replace my Continuum 500 and I'm finding it's 1000 watts into 4 ohms and very refined pre-amp section up to the task of driving my speakers and managing my system.

Running the Spectrons bridged as mono-blocks yields astonishing power without sacrificing anything in detail and refinement.

I have not heard the Spectron or Bel Cantos in my system, but only in show systems, but I heard enough to tell me that they're making contenders for serious system.

The cosmetics of the Rowland are amongst the best for my taste. Those cosmetics are backed up with solid, close tolerance chassis design that's more than a pretty face. IMHO, you can't go wrong with Rowland, unless you're expecting your amp or pre-amp to warm up the sound. If you like neutral, transparent and dynamic, then you need to look at Rowland.

Dave

I can make my class D system sound sublime or miserable depending on what I hook my amps up with. I know, because I have done it time after time.

Every time someone brings over a glorified digital filtered digital source, the sound closes up, harmonics are lost, proper gradual decay becomes severely truncated.

Non-shielded power cords will strangle the sound. On the flip side, unnecessary insulation on speaker cables will transmit white noise.

Use ordinary power cords, good ol' hose speaker cables, and a wonder SACD player, and you have a class D disaster in the making.