Class D Technology

George not much buzz on the new technics gear yet. Maybe to come. I was in their room at Capital Audifest but they kept talking about the gear and did not play it while I was there. I wanted to hear and was disappointed. Nobody had it in their best of show list that I’ve seen.

No doubt higher switching frequencies done well is better. How much better practically in regards to what can be heard is TBD. I will say that each newer generation of Class D gear does seem to only improve so not at the end of the road yet.

I try to hear these high frequency artifacts in my Class D amps that I’m supposed to hear and have not heard it yet. So if it exists it is not blatant. At least to these 57 year old ears.

Again there is often more noise at the highest frequencies human ears can hear than music. So perhaps its an error of omission mostly to the extent present at frequencies that really do not matter much for listening to music.

Take a look at the audio frequency chart and you’ll see what I’m talking about in regards to at what frequencies music mostly all occurs.

http://www.independentrecording.net/irn/resources/freqchart/main_display.htm

Mapman, high frequencies are different for sure, but not for the worse.  Cymbals, for instance, sound more "brassy" and less "splashy".  To me it sounds more natural, but it might create false impression of limited extension.

Cymbals, for instance, sound more "brassy" and less "splashy".  To me it sounds more natural, but it might create false impression of limited extension.

If the switching noise output filter is set at a higher cutoff so to make the amp look to be flat to 20khz on test this will sound hard.
If it's set lower to try to rid most of the switching noise, this will already be rolling of at 10hkz and therefore rid any cymbal harmonics, this will sound more natural but not very extended.
So your compromised either way, the only solution is a much higher switching noise so it can be cut out totally with the output filter without effecting the audio band at all.

Cheers George  

I'll cast a vote with mapman re a D with a Walsh driver.  Although it's just a 'dinky' driving two pairs of my smaller DIY versions, it's a good fit.  As long as I don't get exuberant and crank it to clip, it's amazing to me how well it 'fits' them.

They'll improve as time goes on.  Pretty soon the electronics will shrink to near invisibility and we'll be left with just the interfaces and the radiators.  I'm working on the latter, myself. *S*

Again, switching noise is inaudible, unless anybody can hear 500kHz. Even bats won't hear it.  I'm not sure why is it so difficult to understand.   I addition tweeter's membrane won't move at all.  Personally, I have problem hearing 20kHz.  As for the bandwidth -  in my amplifier it is set to 60kHz -3dB.  Different sound, more tube like, of class D amp can be explained by low TIM distortion, often responsible for the sharp splashy sound (added higher order odd harmonics).  Class D is in fact so clean sounding that sibilants, for the first time, still strong are very clean and wonderful sounding on every record.

Somehow people cannot comprehend that class D amp is purely analog and switching itself is inaudible.  Switching is present all the time - even without input signal.  Place ear against the tweeter and you will hear very low typical amp's hiss - likely much less than with any class AB amp.
From the sitting position nobody will be even able to detect that amp is ON.