Anyone using a Class D amp w/ribbon tweeters?
I’m not a big fan of Class-D yet, but the best one I heard was the Belcanto M600 monoblocks, and this was driving a two way speaker that had Ravens best ribbon tweeter, and it was I believe because the Raven tweeter was a very benign 8ohm constant load, compared to when I heard that same amp with normal dynamic drivers. Cheers George |
@georgehifi Thx, I’ve only heard of high marks for the bel canto Ref600 Monoblocks. And I have read that with each generational evolution with Class D, that we’re getting about a 10% jump in SQ pretty much across the boards, but particularly in improving the high end sibilance and listener fatigue. Apparently we are in the 3rd generation now (?). |
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 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 |
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. |
1graber2...Sure you can ask.
I am using the Merrill Audio Veritas mono block amps driving the Acoustic Zen Crescendo Mark II's. A little piece of heaven... |
@1graber2 I am using ICEpower 25 ASP based mono blocks. One under each speaker. Literally. :) My ribbons are from Mundorf. Sound fabulous, but electrically VERY different than a ribbon. Ribbons tend to be very low impedance, and need a matching transformer. AMT's have no need for a transformer, and are almost purely resistors (relative to most drivers). Best, E |
@aolmrd1241 Yeesh, this Merrill Class D monos are ridiculous! (aka awesome), as described on the Merrill site, "Start with a 66 pound of Aircraft grade 6061 solid aluminum block. Delicately machine the chassis from this solid block isolation chambers to limit any sonic interference and minimize vibrations. Keep the walls 1 inches thick, to limit and absorb vibration. The result is a ..." |
and I hear no top end sibilanceWhat I’ve heard is either two things in the upper/mid highs from Class-D, either sibilance as mapman mentions or an opaque whiteness. This to me comes from "high power the low order switching noise output filters" either "set too high" which lets through too much of the switching noise (sibilant) and some audio band phase shifts, or "set too low" which hacks out most of the switching noise but also hacks into the audio frequencies upper mids ,highs (opaqueness) and creates not only attenuation but even larger phase shifts than the "too high" filter does. The only way to fix this to me is to raise the switching frequencies much higher so the "high power low order output filter" can do it’s job properly without any effects down into the audio band. As Technics have started to do with the flagship SE-R1 with more twice the switching frequency of today, but at $30k aud and limited supply. BTW you can see this switching frequency noise on Class-D amps in Stereophile bench tests that sits on the 10khz square waves, like a buzz saw across the top of the square wave. https://www.stereo.net.au/forums/uploads/monthly_2016_12/583f6e91157f6_Class-Dsquarewaveringing..jpg... But last year or so Stereophile have introduced a special filter (Audio Precision’s AUX-0025 passive low-pass filter) that goes between the the Class-D amp and the test measuring equipment that gets rid of the buzz saw, just for Class-D tests purposes, they always say they use it somewhere slightly hidden in the bench test reports. ( Belcanto with AUX-0025 filter applied https://cdn.head-fi.org/a/1862061_thumb.jpg) Still to me a disgusting looking 10khz square wave, but better than the buzz saw with the special filter. This is what a proper Linear Class-A/B amp square wave looks like. https://cdn.head-fi.org/a/1862052.jpg Cheers George |
Igraber2 the c5i is had to fault. Simply wonderful. About the size of a shoebox. 60 watts perfect for my second system. If it just had more watts I would put it in my main system and just forget all the separate components. My main system is ARC sp 16 pre to Bel Canto ref1000m Class D amps to large OHM Walsh speakers with 12" driver that love power and current. If the c5i did not work out I was going to go tube amp. Never happened. I've had the c5i for a few years now. |
dsycks15 posts08-25-2018 9:18amI ran BelCanto with Magnapan 1.6s for years.Yes, I can imagine it was, as in my first post about the Raven ribbon tweeter with the Belcanto M600’s, Maggies are also similar "usually" a nice smooth benign mainly resistive 4ohm load. Cheers George |
I have heard 3.7is as well as a pair of Vapor audios with Raals run on Jeff Rowland's 525 and the new Kinki Studio integrated. All gear was pretty well broken in. I listened to tracks I knew well. Class D (to me ) has come a long way. I had no issue with high frequency harshness. They seemed sensitive to the power cables we ran, different materials colored the music noticeably. The value is absolutely there for both these compact monsters and they like to be good and warm before they perform. |
dsycks "I ran BelCanto with Magnapan 1.6s for years. It was pure sex." ------------------------------------ LMAO! which bel canto’s? REF 500 Monos? Ref 1000 mons? |
