The Future of Audio Amplification

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. 

so Kosst, are you saying all class D has audible distortions? What about A and or A//B? Don't they as well?

I have a 20 amp dedicated line, Core Power 1800 PC for front end . I bought it for my amp/s too, but they sound better plugged direct to wall. I use both WireWorld PCs and a couple from Tekline Audio, which sound better, but are 2+ xs the price, although WW has more expensive PCs too

Kosst. You have repeated your stand about specifications on distortion, overshoot of square waves, etc,etc. But you have eluded the simple question many of us have asked you, "have you listened at length, (weeks, months) to any viable Class D amp in your own system. I have no problem with class D not being your cup of tea, just you and other nay sayers believing it is junk and should be dismissed. To many well trained ears here have had wonderful experiences with class D, myself included.
Tim

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.

Pass makes the opposite argument you are making. Your argument is: I can see it has more distortion so it’s bad.

Pass’ arguments are that MORE distortion is favorable.

Further, he’s adding distortion which is in the audible frequency spectrum. Your claims Class-D switching noise (i.e. distortion) are in the RF frequency range.

So, we are back to : Is switching distortion from Class D amps audible or meaningful? In fact, none of the claims of sonic inferiority here even point to that. The only counter points I hear are of sterile sounding, or lacking dimension or engagement. Which of these problems do you think come from switching noise and distortion?

George insists that high speed is where it's at, based on no particular evidence. I mean, what exactly is high speed? What is too low? What is high enough? You have to buy into the idea that you have an audible problem to begin with.


Best,
E

For years I poo poo’d Class D in the same fashion as Kosst has here. But, because of curiosity and a sense that a company I trust, PS Audio, wouldn’t be spouting off about how good these amps are if it couldn’t be backed up, I decided to try a pair of their class D monoblocks.

They sound better than ANY of the MANY of non-Class D amps I have owned in the past, not only to my ears, but to several of my audio buds who have now listened and who are both tubed and solid state (non-Class D) amp owners. They ALL agree that my system sounds significantly better than before with these amps.

I took a chance and am now convinced that the technology has arrived at level consistent, and exceeding, the sonic perfomance of ANYTHING out there.

Also, this nonsense about caps burning up early due to the switching technology is a lame attempt to scare people in an era where fear reigns supreme. Good electrolytics last a long time. Enough of this fear mongering.

Horseless carriages were deeply despised and 'destined for failure' when they started out too. Any car owners out there?