Class D Technology

3 of the main reasons manufactures choose use smp (switchmode) power supplies.
Size/weight, efficiency, and cost to manufacture.
 
Well designed linear power supplies, are still the supply of choice for performance/noise and reliability. But they are costly and inefficient.

If/when I go to Class-D amps, I would also prefer to have a well designed linear power supply powering it.

Just quickly two that I can think of that use linear supplies for the best result they believe to power their Class-D amps are. Mark Levinson and Rogue Audio, there are many more from the upper end of town.

http://www.stereophile.com/content/mark-levinson-no53-reference-monoblock-power-amplifier#OXQH9C1XSJuv27p5.97

http://www.rogueaudio.com/PDFs/Pharoah.pdf   

Cheers George  

The main reason manufacturers of high end audio (like Rowland) use SMPS is low noise and line/load regulation.  You can find it in FAQs on his (or Benchmark) website. He uses SMPS  in preamps where size or efficiency play no role.

Yes, top manufacturers still use linear power supplies, but main reason is demand from people who, mistakenly, believe that if it has to be heavy to be good.

Yes, top manufacturers still use linear power supplies, but main reason is demand from people who, mistakenly, believe that if it has to be heavy to be good.

Sez who???

Cheers George

Well, most of people on this forum (including you) think that SMPS is noisy and linear power supply is better.  This believe comes from bad rap of noisy crude computer SMPS applications.  They don't even realize that "Linear" power supply is a primitive unregulated switcher.  I addition, many believe that when something is smaller and more efficient something else has to give (that's human nature).  They apply this believe to both SMPS and class D amplifiers (that are basically controlled SMPS).  In view of that amplifier manufacturers would be stupid not to keep using "Linear" power supplies.  Only few true pioneers like Jeff Rowland had courage to develop state of the art SMPS supplies that are extremely quiet  (noise very easy to filter out at 1MHz operation).  Even 50kHz SMPS executed well are far better than "Linear" supplies IMHO.

So much noise about nothing of real consequence.

I will of course look forward to improvements in switching frequency under the assumption that things will get even better overall down the road at least on paper. How much difference it makes practically is TBD.

George I do think you are too obsessed with this one technical issue. You should do a study to see if class d amp sound quality correlates strongly to switching frequency alone. To hell with all the rest that goes into these things if that is all the story.