Class D audio vs James Romeyn

m-db,
That's very kind of you to mention, but I took absolutely no offense. 

For the record, there are a couple fine points Re. NC400 assembly.  On at least six occasions, clients hired me to re-wire the same subtle assembly error for NC400 built by persons not me.  The symptom of this error is NC400 works perfectly fine in one system, then moved to another system NC400 mutes, playing no music.

Again, please allow me to repeat this performance advice for all applications w/unbalanced source > NC400.  Any use of unbalanced IC unnecessarily and audibly degrades performance of this fine amplifier.  Instead, follow this IC method:
Unbalanced source > Quasi-Balanced IC (RCA/balanced cable/XLR) > NC400 XLR, or close second choice...
Unbalanced source > RCA/XLR adapter > balanced IC > NC400 XLR

The worst application, w/the greatest magnitude of AC mains noise, is the following:
Unbalanced source > RCA IC > NC400 w/RCA input and "earthed" chassis

I would like to share my experience/impression with class D amps.  I started with a Virtue Audio Sensation.  It was good but when I switched to Bel Canto S300i it was an amazing improvement in every aspect.  Just over a week ago I switched to ClassDAudio SDS-470C with upgraded power supply.  The improvement from Bel Canto is amazing.  Now I feel it is closer to good ClassAB amps.   For the remainder of my system I have a Squeezebox touch and Monitor Audio Silver 2 speakers.

bharavi,

You stated: " Just over a week ago I switched to ClassDAudio SDS-470C with upgraded power supply. The improvement from Bel Canto is amazing. Now I feel it is closer to good ClassAB amps."

Glad you’re enjoying your new ClassDAudio SDS-470C class D amp. I’m somewhat surprised it outperformed your Bel Canto class D integrated but I’m not surprised at all that it sounds very good; I own the model just below the 470, the SDS-440CS, and it was a similarly great performer in my system.

It has an extremely low noise floor, solid bass along with a very detailed, smooth mid-range/treble that is never too bright and with an overall neutral sound quality which is very revealing of upstream components. I found the neutrality of this amp allowed the system sound influence of my VTL preamp with NOS Mullard tubes to simply be accurately amplified, without any detectable alteration or added sonic signature of its own to the sound, which allowed it to nicely flavor my overall system sound with more texture, dimension, realism and warmth; just what I was wanting at that time.

I do have to differ, however, with your description of the sound as "being closer to good class A/B amps".

In my experience with the SDS-440 and several other class D amps I have subsequently used in my system after switching from a decent quality class A/B amp (Aragon 4004 MKII), I think the overall performance of the 3 class D amps I’ve used thus far (ClassDAudio, Emerald Physics and D-Sonic) have all significantly outperformed my former class A/B Aragon in virtually every positive amp quality; more neutral, better bass, a lower noise floor, better dynamics, more detail with similarly good sound staging and very good mid-range’treble performance.
In my opinion, many of the current good class D amps come much closer to the traditional audio amp ideal of a ’straight wire with gain’ than the recent and current good class A/B amps can muster. I have found them so neutral and revealing that I can now more easily detect the affects of system changes such as power chords, interconnect cables, speaker cables and changes in upstream components.
Due to the superior sound performance I perceive from the current good class D amps when compared to the current good class A/B amps along with class D’s additional advantages (lower price, smaller, lighter, more efficient and cooler running), I replaced all the class A/B amps in my combo music and HT system with class D amps. This switch has been completely beneficial in my system with zero negative affects that I’ve been able to detect in the past few years. I honestly cannot think of a single advantage that class A/B has over class D unless you oddly and sadly somehow misconstrue the imposing size,weight or looks of some class A/B amps as positive qualities.

Tim

I ended buying Class D audio with upgraded power supply. Had Audiosmile supertweeters and very happy with the result. Now looking to buy some relatively cheap (up to $1500 R2R DAC). Looks like Soekris will start shipping one for $1200  in early June.
Thank you everyone for the very useful info.

  Ouch,  that's got to hurt 
Some prices are north of 15k.  They better be damn Good ,   Who said that! 
     D class will never be as good as A or a well done AB or a great tube amp.