Anyone using a Class D amp w/ribbon tweeters?

I don’t hear top end sibilance on either the NC500 or 1200as  based amps nor on the proprietary modules from Nuprime. You can try the first two types for right around $1000 new. Just like the other types all Class D implementations are not the same or equal.

but particularly in improving the high end sibilance and listener . Apparently we are in the 3rd generation now (?)

Yeah we’re getting close to me selling my hot, energy sucking, boat anchors.

When future technology allows the switching frequency of Class-D to be taken from 600-800-khz to around 2-3mhz so the output filters can do their jobs properly. This is day the day my boat anchors will become obsolete.

Technics with their $20k usd SE-R1 is on the right path with a switching frequency of 1.5mhz using the new limited gallium-nitride (GaN) semi conductors, who’s designers were the same guys who invented the Power Mosfet

Here’s what one reviewer said about the SE-R1
" Listening to tracks that we’ve heard 100s of times — and on excellent systems at that — is now a revelation of once hidden nuance and detail. Not only are we hearing things we’d never heard before, we’re hearing it in a way we’ve never heard it before. A music system that sounds like a live performance is a tough goal to attain, but Technics’ flagship nails it."

I don't know if this is real or a hoax, but there was one actually for sale on Audiogon
https://www.audiogon.com/listings/lis8hiab-technics-se-r1-power-amplifier-solid-state

Cheers George

George

See if you can get a listen to these.

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

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