Anyone using a Class D amp w/ribbon tweeters?

jackd135 posts08-24-2018 3:39pmGeorge

See if you can get a listen to these.

http://nuprimeaudio.com/product/evolution-one/?v=7516fd43adaa

Still the same switching frequency at around 600khz, to me it’s too low for the low order output filters filters to get rid of it all without having bad phase shifts (artifacts) down low into the audio band.
That why in older tests you still see switching noise across the top of 10khz square waves. https://www.stereophile.com/images/1212AM1fig02.jpg )

(Unless lately, last year or so Stereophile have been filtering it out in testing, with "Audio Precision’s auxiliary AUX-0025 passive low-pass filter". a high order "but very low power handling filter" between the tested amp and the Oscilloscope picture
https://www.stereophile.com/images/418BC600fig03.jpg just so you don’t see the switching noise on the 10khz square wave, which I believe is not the right thing to do, as that filter is not there when you listen because it can’t handle any power at all.

Technics SE-R1 switching frequency is around 1.5mhz, better, because it’s phase effects are not into the audio band so much, but 2-3mhz would be best.

Cheers George

BTW: From what I’ve been able to find out, the above "Audio Precision’s auxiliary AUX-0025 passive low-pass filter" used in Class-D bench tests, is a 60db per octave passive filter.

Cheers George

I’ve heard sibilance in some recordings over the years , and I hear no top end sibilance produced by the Bel Canto ref1000m.

The BEl Canto c5i is a newer model and the top end on that is perhaps the most relaxed of any amp I have owned.

In practice, I find fears of Class D deficiencies these days are totally unfounded. i will likely only go with Class D amps moving forward as needed. At one point I considered tube amps but Class D amps put an end to that need, though I still like tube amps as well especially if well matched to rest of system, but I do not like the additional cost of ownership due to maintenance, etc. In teh end I’d rather spend as much time as possible just listening to the music and Class D enables that very well.

My class D amps sound wonderful with my ribbon tweets...

@aolmrd1241 
can I ask which Class D amp? 
Which speakers with ribbon tweeters?