The Future of Audio Amplification

As kosst alluded to, class D is not a new technology and was developed largely by Phillips for the sake of specific engineering requirements such as one would find in an hearing aid for example.  Class D has had a renaissance of late due in part to engineering or rather manufacturing convenience (who wouldn't want a kit you could pop in an aftermarket box).  

No one has provided a logical, technical counterpoint to kosst's argument regarding class D other than experiential vignettes.

I for one have owned the gamut of amplification (including several class D variants with multiple iterations of Hypex and a DIY amp from Class D Audio).  Class D was pleasant enough (with a tubed pre-amp), but failed to hold my attention and seemed vaguely flat and bleached for lack of a better description.  I have regressed back into the archaic world of tubes (Trafomatic 300B integrated) and the music is back.  To each his own.  With audiophiles, the rubber meets with the road with duration of ownership.      

No one has provided a logical, technical counterpoint to kosst's argument regarding class D other than experiential vignettes.

No one has proven the measurements Kosst has alluded to are audible on the other side of a speaker.

All Kosst has done is noticed 1 measurement.

There are plenty of ways in which Class D is as good or better than many SS and Tube Class A, Class A/B amps.

Noise and frequency response and low output impedance in the audible band among them.  Why don't we count those 3 as better than Kosst's single measurement?

Why do you think Stereophile uses an output filter in the first place? Because it is more meaningful that way.  What makes Kosst such an authority that he can disregard it?  Puhleese.

plga,

Congratulations on the Nord. I too have the LM508IA and largely prefer it over the W4S ST-500 mkii class D. The W4S had great lows and mid bass but sterile mids and hard highs. Heck I even liked a 20 year old parasound HCA-1200ii better. I can see how a tube pre could work wonders instead of my DAC-2 pre on a class D amp.

What get's me is how much a positive difference quality room correction makes. How many commenting on Class D vs. A/B, SS, tubes have made these comps with room correction and separates? My experience was that class D was stark, bleached, just plain fatiguing. I'm sure a better/new class D amp would sound better. 

The exacting results of RC may have synergy with one amp and not another and knowing the differences RC makes, I never A/B compare without it. Could the Lyngdorf 2170 buzz be largely attributed to room correction?

I for one have owned the gamut of amplification (including several class D variants with multiple iterations of Hypex and a DIY amp from Class D Audio). Class D was pleasant enough (with a tubed pre-amp), but failed to hold my attention and seemed vaguely flat and bleached for lack of a better description.

This common even with those that persevere with it as above.
But some don’t hear it, and because they can’t hear it, they say those that do are full of it, even if measurements are backing them up.
Bet you thought there was nothing wrong with the bass though
.
I still believe it is the future, just not yet, I think the Technics and Merrill ones with GaN technology, are going to lead the way, and take Class-D where it needs to be to compete with the hiend linear amps.
The others at the moment are great bass amps, but not hi-end yet elsewhere in the audio band..

Cheers George

20kHz is hard for any amp to do, much less well???

http://www.firstwatt.com/pdf/prod_f5_man.pdf

Look at page 17 where the FW F5 absolutely nails a 200KHz square wave at 1 watt. A lot of amps are designed to roll off at or past 20KHz more for purposes of self preservation than technical limitations. You’re always going to have that guy who wants to try Litz wire ICs and create a high power oscillator.

@erik
I don’t recall the amp model, but Pass installed a pot on the front of the thing to dial in the distortion character ranging from a few hundredths % positive phase second harmonic to a few hundredths negative phase. Anybody looking for proof that .0X% distortion does make an audible difference, there it is. The exact same effect can be achieved with the F5 and I’ve done it. Nobody is going to tell me .05% means nothing because I can hear it and I’m definitely not the only one. Nobody is going to tell me noisy, overshooting, sloppy amps are great when I'm looking at measurements like the F5 and hundreds of other well regarded amps which have been designed by guys correlating measurements with perceptions through thousands of hours of listening trials by skilled listeners. 

Sorry folks, but I’m very unimpressed with an amp that has 75mV of overshoot on a 1V 1KHz square wave. 800mV of high frequency noise on the outputs isn’t real sexy either. I’m not expecting every amp to drive 200 watts DC into a 1 ohm load, make text book square waves at 200KHz, roll off 3dB at 1MHz, have less than 60mV of noise on the outputs, or make .002% 3rd order distortion, but it’s nice.