Class D Technology

I have two integrateds, an Audio Research VSi55 running KT120s and a Peachtree Grand X-1 (Class D).  Through both pairs of speakers I own, Wilson Benesch Arc and BMC PureVox (both retail for $6500, whether these qualify as low-fi, mid-fi or otherwise is a matter of perspective and budget), I'd choose the Peachtree every day.     It sounds every bit as nice as the Audio Research, but runs cool, keeps the electric bill low, and takes up very little space while putting out huge power.  I guess admittedly there are a few cold days each winter where it's nice to use the Audio Research to both play music and heat the room, but otherwise it collects dust.   So I guess in my case, the future arrived 3 years ago when I bought the Peachtree. 

All that stuff about switching frequencies and flux capacitors and quantum math, I don't know anything about that.   I just press the power button, hit play, and sweet music comes out.  For all I know there's a team of hamsters inside the Peachtree playing little tiny violins.  I leave all that stuff to you engineers...if it sounds good, that's all I need to know. 

George, I looked at the link you provided.  Yes they use filters for the purpose of measurements to eliminate residue of switching frequency that is otherwise completely benign. This small residue (about 1%) has no effect on the sound.  Speaker membrane will react (move) to its average value only.

I don’t buy the "gas guzzler" A/B vs. "green" class D arguments for the latter. Kilowatt hours are cheap and relatively clean until you pile up a WHOLE lot of ’em. With typical audiophile usage patterns, and the fact that we’re a VERY small segment of the population, there’s no significant ecological impact here. 

According to this pouring used car engine oil to kitchen sink is OK (does not have environmental impact) since very few people do it.

And as far as ecological impact, class D probably makes things worse overall, due to the fact that audiophiles ship ’em over, decide they don’t like the sound, and then ship ’em right off again

That's funny.

This small residue (about 1%) has no effect on the sound

Put your ear to a wide bandwidth tweeter, you will hear it’s poluting artifacts. If not the filter effects is set very low to cut way down to 10khz or even less, creating all sorts of other problems.

Cheers George

Let me add that while I do concede that my engineering knowledge falls short of what many of you possess, there's still a lot of bat guano peddled on these forums.   I like it here, and there are some very smart, very cool, very interesting people that I've learned a lot from, but oftentimes this forum is to audio knowledge what Fox News is to global news coverage.  Sometimes after I visit I have to remind myself that I didn't just spend 10 minutes on Shutter Island.

Here is just one of many that Stereophile tested, not using their test filter. It’s more than 1%.
And this Class D had a linear power supply as well, most use smd now which creates even more other noises as well.

http://www.stereophile.com/images/archivesart/805CIAfig2.jpg

Cheers George