Class D = Trash?

Again can't see the forest through the trees.

Not one mention of the output filter that has to address the switching noise of the switching frequency, which is the Achilles Heel with present day switching frequencies.

Cheers George

" Not one mention of the output filter that has to address the switching noise of the switching frequency, which is the Achilles Heel with present day switching frequencies."
George,
     I understand the importance of having a good well matched passive filter in class D amps to remove the ultra high switching frequencies from the signal path after their Pulse Width Modulation job has been completed. I agree that this is a critical component in the process since this is where your theory states these switching frequencies can affect the audible range if not completely filtered out.

     Perhaps I just got lucky and only bought class D amps with exceptionally good passive filters. If they weren’t so good, maybe I could catch a trace of the switching frequencies affecting the audible range that you mention so often. Thank you, George, I think you just might have solved the mystery of the missing sonic artifacts/anomalies in my, and likely boatloads of others’, class D amps. No wonder nobody believes your theory; All the evidence is being filtered out effectively just as designed.

     Please tell me the class D amp brands and models of class D amps you were able to detect some audible artifacts from. We can compare all the specific filters operating flawlessly in our class D amps to the specific filters obviously working so poorly in the class D amps you listened to that inspired your infamous and discredited theory.

Thanks again for your help,
Tim

Yes, and they are the industries top designers, nothing will change until that dreaded switching frequency is taken up much higher. So then the output filter can do it’s job properly without any effects down into the audio band.

Technics is leading the way with the SE-R1 with twice as high switching frequency, but it’s not mainstream yet, and really should be even higher, one can only hope.

Cheers George

It’s not just the switching frequency, but a combination of that..and some other potent problems. Some things can be done to fix it and I have my ideas on how to tackle these critical ’other’ problems. The solutions are all valid on paper, but the real world may say different. I have successfully dealt with these problems in other arenas of design, so the knowledge should be transferable. We shall see. That, is, if I ever manage to get to the point where I can spend time fooling with these Class D problems again. Too busy cranking cables out the door right now.

I tried to do it on my own re existing modules (retrofit), but (un)said company wanted no part of it, unless it is in their domain - so I declined.

I have a pioneer sc68 which has class D amplifier. I have it hooked to KET 205/2. The sound is just beautiful. Just clean sound with details about all the different instruments in the music. Steve Wonder ribbon in the sky feels like he is singing in the living room :)
Also I am not sure what warm up period of 1000 hours mean.. It does not make any sense to me as I read these posts. The speakers need warm up period because they are mechanically moving parts that need to settle or get flexible.  If electronics change behavior that much with time.. that's scary to me from a Computer engineer perspective.

The 1000 hours is urban legend with no basis in science or audible difference to a golden ear.