Class D

This statement is wildly incorrect! So this isn’t just about power!!

It’s more about power, because you can’t see the forest for the trees, with what Mark Levinson tried to do by series up "low order" output filters (so they don’t burn out) and trying to get a steeper roll off as not to introduce phase shift into the audio band in the upper mid/highs, which they achieved, but it had then other problems. https://www.stereophile.com/images/1212ML53fig02.jpg
Instead the simpler fix of of doing what Technics SE-R1 did and just raise the switching frequency to 1.5mhz.

It’s more about power, because you can’t see the forest for the trees, with what Mark Levinson tried to do by series up "low order" output filters (so they don’t burn out) and trying to get a steeper roll off as not to introduce phase shift into the audio band in the upper mid/highs, which they achieved, but it had then other problems

This comment really says you don't understand what's going on here. ML didn't do what you're describing. Its obvious from the internal photos that the circuit employs what is known as an 'H' bridge output (which tends to be common in higher powered class D amps). Its also common to see two chokes as a result- one for each half of the bridge circuit. Without knowing further details of the circuit its unwise to speculate further, but the fact of the amp being an H bridge is easy to see if you know what to look for.


The waveform at the link is a 10KHz squarewave. There is a small amount of overshoot, and what looks like a bit of an oscillation on top of the waveform as it is consistent with each iteration so does not appear to be a measurement error. As square waves go, that's not a bad looking one- most power amps will round the leading edge (if open loop/zero feedback you need 100KHz bandwidth to make that leading edge look right).


So I don't see the 'other problems' to which you referred by including that link. I might add though that more modern class D amps do make a better showing of this sort of thing. When you attack a technology based on older examples, it really doesn't help your argument!

Must be soon, you really have gone into full product protection mode, and there’s no stopping you.
Good luck is all I can say, for your new Class-D venture.

And Class-D technology has not progressed as much as you want all to here to think (for sales), sure the GaN transistors that I first showed here years ago as a far better alternative for Class-D, you were quite negative about back then, and now you say you use them. How ironic.
I first showed the GaN power transistors from EPC (https://epc-co.com/epc) inventors of the Mosfet, to all here many years ago, and yes they have improved things a little, but the only one to use them fully and make a dent in Class-D’s Achilles Heel "switching frequency/switching noise/phase shift" has been Technics with the SE-R1 and hopefully the new SU-R1000 integrated has the same genes.

Do what I did. Call a tech/sales rep at Sweetwater. Couldn't be nicer and more thorough if he tried. The first purchase was a Crown XLS 1502. Really couldn't be more pleased with that unit. Quiet and tons of headroom; ran a set of Ohm Walsh 5's like nothing. Those have been sold and replaced by a well loved pair of JMLab Mezzo Utopias with a little preamp and a Crown XLS 1002 which to my ears produce nothing less than aurel bliss.
Good luck.

Please don't be stupid.  It is stupid to respond to George.....he is a rock....he will never move from his position.....and he has to have the last word.......so it will always go on and on and on.  Don't be stupid....he does not want to learn....he just wants to be right.  Let it go.....let him go.  Just let him post what ever nonsense he wants and pretend it does not exist.  You will be much happier, if you do.

What we really need is feedback from those that have listened to the latest class D amps versus the latest class A and class A/B amps (within the same price ranges).  We need actual listening test impressions.....not all this guess work.....it is just a bunch of noise.

The Technics amp that is about to be released has tons of stuff inside that could make it sound great.  Technics does not even mention 1.5 meg or phase shift in their literature.  This thing could be really fantastic.....but there is no way you can say it is because of 1.5 meg or phase shift.  Please read all the info....very revolutionary.  It has 4 switching power supplies that switch at 500K....It is not really a standard class D at ALL.....it is fully digital (like the original Tact amp and Lyngdorf).  It takes an analog signal and converts it directly to high speed PCM and does all kinds of low jitter manipulations to make the distortion go down.  The PCM signal is then changed in software directly to PWM (class D).  Please read all the lit.

https://www.technics.com/us/products/reference-class/integrated-amplifier-su-r1000.html

https://www.technics.com/us/about/press/releases/20200901-su-r1000/index.html

https://www.youtube.com/watch?v=b-BJifbtjbI

George did start a thread on this new goodie....so when this comes out and people have listened then we will have a REAL idea of how good it is.  It looks great....I do hope it sounds great too.