Class D Technology

I am going to chime in here in favor of current class D amps, with a big thumbs up! I have been in the tube amp camp (both SET and others) for 20+ years, and now I am happy as can be with my Red Dragon S500 amp. No, it's not like a tube amp, but it's not SS sounding either.  It does so many things right, and hardly anything wrong, that I can easily live with it. All topologies have their pros and cons.  Throw a tubed preamp in front of a Class D, and there you go! 

George , I did put my ear to the tweeter and I can hear almost complete silence - much better than class AB amp I had before.  I'm not surprised since tweeter membrane has no chance to move at 500kHz.

Modern SMPS are much quieter than linear power supplies that, in reality, are very primitive noisy switchers operating at 120Hz.  Modern SMPS switches at zero voltage/zero current while much ripple is much easier to filter out than 120Hz, that requires huge amount of capacitors (that produce unwanted inductance that is in series with the speakers).  In spite of all capacitors linear power supply in power amps is unregulated.  Because of that Jeff Rowland does not use linear power supplies at all.  He uses SMPS even in preamps to lower noise floor.  Benchmark replaced linear power supply in their latest DAC with SMPS lowering noise floor by 10dB.

Mapman is right - you're not sold on class d yet.  I enjoy my class D amp immensely.  Efficiency is not that important to me (but it should), but is always welcomed as added benefit.

Class D is for subs, or car audio. 

Ill keep my A/B amps.  

You aren’t sold on class d yet.

Correct, and Technics are showing the way with the SE-R1, why strive for higher switching frequencies by deleloping their own components, if what we have off the shelf is "good enough". Technics knows and are doing something about it, they can see the forest through the trees.

And like I said when they do get the technology to make it much higher I will be the first to change over, till then I’ll stick with linear for hiend amplification.

Cheers George