I thought it was time we had a pro- Class D thread. There's plenty of threads about comparisons, or detractors of Class D.
That's fine, you don't have to like Class D amps, and if you don't please go participate on one of those threads.
For those of us who are very happy and excited about having musical, capable amps that we can afford to keep on 24/7 and don't require large spaces to put them in, this thread is for you.
I'm afraid I haven't had time to go out and listen to a lot since the last show here in ... Long Beach? Newport Beach?
I've also gotten to a poin where I'm very happy with the sound quality at home but not the remotes. :) Seems bad for me to find a dealer to listen to gear I'm not going to buy.
Maybe I should ask manufacturers to send me gear to review instead??
I just finished reading this thread from the start. I have to say that of all the areas of audio, I find the class D debate to be the most diehard and in some ways hardheaded; its almost like politics.
I think, like a lot of things in life, the danger or pitfall comes with the broad generalizations - e.g. all class D is (crap, lacking, great, musical, whatever); or the best class D can already compete with anything (or no chance against good class A at other end of spectrum), and with having intractable positions. But to each their own. I’m not here to change minds, and I don’t have strong opinions on the class in general, just making an observation.
I think it’s much more fruitful to focus on specific models and thoughts on them, rather than trying to paint whole class with a broad brush. I’ll give an example.
Two of my three systems use class D amps, the other class AB. My main system uses class D Audio Research DSI200, and paired with my Spendor D7 and Teac NT505 to my ears sounds absolutely amazing. I don’t foresee changing anything for 10 yrs. My third system uses class D Bluesound Powernode 2, and paired with my Spendor SA1’s to my ears really leaves me wanting, to the point of hopefully I’ll soon be replacing it with similarly priced class AB Marantz pm7000n.
So fwiw I personally love one of my class D’s and can’t wait to replace the other. So I’ll stake out a new position in this thread: some modern class D is really good to my ears and some is really not so good to my ears. It’s okay to admit both : )
heaudio class D amplifier, with fairly well defined harmonics hence why they can be filtered.
Incorrect, it is you that is saying something false, if it was completely filtered out as you say, then they wouldn’t still look like this, with much residual switching noise still riding on the audio test waves 1-10khz, and with severe phase shift indicated by the inward slope of the sides https://www.stereophile.com/images/1212AM1fig02.jpg
HI @noble100 , GaN is has been around for awhile. Several manufacturers are using it. It is an interesting material, not only is it fast it is also more energy efficient. I have heard it in Class A and Class A/B products. So you can find amps using this material and they may have no heat sinks or small heat sinks.
It seems no matter how factual I am you complain about me being abusive to you.
You have made dozens of posting on this thread, and ignored the request in the OP and myself and others to start an anti-Class D thread if you are so inclined.
You've also made the same arguments dozens of times.
Would you please be a gentleman and go start your own Class D bashing thread?
Thank you Erik for starting this thread. Since I am a manufacturer and of Class D at that. Therefore, I am obviously biased. So I think my comments isn’t worth much and rightly so I suppose. Anyway, I won’t get into endless debate on the technical mumbo jumbo, rather to say that class D CAN (and this is the key word) sound extraordinary. Then again, the same can be said for tube, conventional class A and class AB design.
As a young electronic technician, and PCB designer, I was entranced at the idea of ultra-wide bandwidth electronics.
We often made gear for theaters that was flat to 100kHz. Very transparent sounding stuff. Tandberg was one of the brands I remember sounding great at the time, with astonishing slew rates.
However, in modern times, I can’t say it has been the slew rate or bandwidth that has won me over at all. Spectral is one such amp, which I heard, and it was OK, but no, it didn’t stop me from buying anything else. That is, if the ultra-wide bandwidth had benefits, it didn't win me over to it.
Thanks to all of the recent kind words. As pointed out, I can't believe this thread is really 3 years old. I can't believe we are still reading and dismissing the same old arguments.
I hope to read more about what new products have come out recently worth listening to.
heaudio , Slope on the edged is not caused by phase shift, it is caused by bandwidth limiting.
Oh dear! Which is caused by the output filter which and causes phase shift and yes if you must have that included, "bandwidth limiting" as that’s what the filter is there to do, without bandwidth limiting you have no phase shift!!!! please get it right.
heaudio
This is another ClassD no filter with a bit of overshoot likely due to underdamping also indicating from a frequency response peak.
You really need to do some more understanding, JA used his high order special testing output filters because he didn't yet have the
Audio Precision's auxiliary AUX-0025 passive low-pass testing filter, which eliminates noise
Stereophile
Audio Precision sells a precision passive low-pass filter to be used between the output of an amplifier with a class-D output stage and an Audio Precision analyzer. Unfortunately, I have not yet upgraded my test system with one of these filters, so to examine the MX-D1's performance at low signal levels, I used an active sixth-order low-pass filter with a 20kHz bandwidth and a floating input.
@H2Oaudio nailed the crux of the matter on the proverbial head. Like amps of other topologies, some class D amps do sound extraordinary... The Rowland Daemon integrated that I am reviewing is definitely one of these. It is already trending to sound extraordinary, after just a little more than 300 hours of break-in.
You've repeated the same 2-3 points on this thread, over a dozen times, with basically the same set of logical debunking happening immediately afterwards.
Are you offended if I ask you to go make your own thread to bash Class D?
It is not appropriate to use an oscilloscope to measure the audibility of signals. If you are having trouble using one, I suggest going to an electronics forum to help ensure you are using it correctly, and are not connecting it in a way that leads to incorrect results.
I just replaced a Schiit Vidar with a Parasound Zonemaster 2305 and find it a great addition to my system (and I really like the Vidar!).
I can’t speak to the technology points being raised however for myself Class D gives me a level of performance that I could never afford in a Class A, A/B amp.
So while not perfect, however when compared to a similarly priced Class A amp a well implemented Class D seems to me to be a significant improvement.
That's right, what I said and why you can't see much switching noise on the square waves Without those "special testing filters" the square wave will look like this https://cdn.stereophile.com/images/1212AM1fig02.jpg Sorry it's is you that needs to get some tutoring on this, as I said the output filter limits bandwidth and also because it's a low order creates phase shift down into the audible frequencies.
So, My two cent begins with , "Have you ever heard of (Flying Mole), amps"? I imported some of these a few years back after a friend in Japan recommended them. The one's I received were about the size of a paperback novel. They weighed under 2Lbs. and were housed in a really beautiful, single piece of "Brushed Silver finished", aluminum extrusion. With a rounded front face. Beautiful piece of gear! And at that size and weight? 160Wpc @4Ohm! They use a, "Bi-phase tech.", that they invented. Paired with a "Schiit", "Freya", tube pre? I found that the Freya, with, "Sofia Princess, Carbon plate", type tubes sounded amazing! Alas I didn't need them as I went in a different direction. I am kind of sorry I sold them all! They were just $220 a pair from Japan at that time. And the story was that they were being developed by the top engineers at "Yamaha", in Japan when word came down that Yamaha would stay, "A/B", when it came to their component separates. The Yamaha crew quit, and started the, "Flying Mole" company. They finished the amp and debuted them to a people un-willing to embrace the tech. "At that time". I also had a 13.6.4.3, surround system for a bit in which I used three, "Rotel", "RMB-1575", amplifiers with allot of success. Five channels each, 500Wpc, @4Ohm, weighing in at 22Lbs. and making LESS heat than my, "Chihuahua"! I did go to, "All tube, All the time, though", awhile back. With, "Manley Lab's", but that will eventually change. The "ZOTL", tube amps do interest me. And since I do live near to Mr. Bern and his Company. I shall be hearing a few of those soon.
with In my experiences with good quality class D ampsThey just faithfully amplify the inputted signaout adding or subtracting anything. They’re like the audio amp ideal of a "straight wire with gain".
which I have proved couldn’t be further from the truth
jollygreenaudiophile2 "Have you ever heard of (Flying Mole), amps"? I imported some of these a few years back after a friend in Japan recommended them.
Yes it was the very first Class-D I listened to and tested back in around 2004, sorry wasn’t pretty, in sound or test against my Threshold Stasis S500 Optical at the time on the ML Monoliths. Then I got a Channel Islands Class-D with linear supply, better but still not near hiend.
Since then the only Class-D that has piqued my interest was the BelCanto 600M monoblocks but only on a 2 way speaker with a very benign 6ohm load, with Raal ribbon
That's fine, you don't have to like Class D amps, and if you don't please go participate on one of those threads.
I'm curious why you'd want to participate in this thread, with exactly the same 3 arguments you've made before. Over and over again, especially since it seems to most readers you keep attempting to hijack it.
Is there a new argument? Is there some reason why you don't actually go start a Class D bashing thread and leave this one for those of us who like Class D?
Also, you have been debunked 50 ways from sundown. Over. And over. And Over. By everyone.
The admins keep removing posts of mine which are factual and impersonal. So I’m going to keep posting smaller and smaller posts to see what exactly it is they are objecting to.
I have Bel Canto 500 monos and a BEL mk V. This is my second BEL, and is kind of the ultimate expression of Dick Brown’s old lineup. Back in the 90’s I had an earlier BEL which I preferred to the smaller Krell and Mark Levinsons. It was really kind of a giant killer, at the time. Now, I’m really surprised at how good the Bel Canto’s sound. Depending on the speakers, I prefer the Bel Canto’s ICE class D to the BEL’s class A. At some point I will have to try the 600M’s.
coffee-jerk At some point I will have to try the 600M’s.
Yes you should, as they to me and others sounded better than the Belcanto Black mono’s and Ref 1000 mono’s, still wouldn’t put them in with linear hi-end territory driving hard loads especially
Yeah, I would have to agree, GeorgeHiFi. The ML speakers you tried the Flying Moles with wouldn't be exactly conducive to a great listening experience. Too bad. I was using Mag-Planar that were really fast and efficient. But still eventually went back to the tubes.
I auditioned Flying Mole at RMAF several years ago. To say that they sounded utterly uninspiring to me would be a magnanimous instance of audiophilic kindness.
Thankfully, even back then there already were phenomenal music makers running in class D... One obvious example was the Bel Canto REF1000 Mk2, which I listened with immense pleasure at the rame show.
And then without their output filter, the input wave form will be
unrecognizable from the output, because of the HF garbage, and melt your
tweeters silently in a nano second.
The operating principle of a class D amplifier is that it uses a filter to eliminate the switching waveform from the output. In this manner Class D shares the function of the filter used at the output of the Berning amplifiers. In either case, this is part of the operating principle and can't be separated out; the idea that anyone would run one without the filter is ludicrous.
The operating principle of a class D amplifier is that it uses a filter to eliminate the switching waveform from the output. In this manner Class D shares the function of the filter used at the output of the Berning amplifiers. In either case, this is part of the operating principle and can’t be separated out; the idea that anyone would run one without the filter is ludicrous.
the idea that anyone would run one without the filter is ludicrous.
Your scare mongering. No one said run or listen to class-D without the output filter, it said to "look" at it. Whichimplied to see it on a scope as that’s what was being discussed, comparing input wave form to output wave form, far from the same or what your implying.
For those that wish to see what goes in and what comes out between Class-D v Linear amplification which is closer to the original input, or closer to "straight wire with gain" as what was the start of this
For those that wish to see what goes in and what comes out between
Class-D v Linear amplification which is closer to the original input, or
closer to "straight wire with gain" as what was the start of this
But here we see a 10KHz waveform, which is difficult for many amplifiers. Imposed on top is the residual, which is about 250KHz, which is low by modern class D standards:
Note the scale on the left side of the image- its not there! There's no way to tell how strong this signal is, but the residual is a clue; its about 1/4 the total waveform amplitude. Since we don't know the power of the amp, we can't say how high this should be but if its 0.25 that would fit for an amplifier that makes 100 watts. If that is so, the amplitude here is half that of the waveform in the the next image, which is 1KHz instead of 10KHz!
George's attempt to put class D amps in a bad light on this account is debunked.
It appears instead there is an attempt to mislead people by a of slight of hand, which doesn't win street cred. The factor of 10 between 1KHz and 10KHz is pretty significant! In order to reproduce a 10KHz squarewave the amp needs bandwidth past 100KHz. That's hard for most amplifiers, tube, solid state or class D.
George, if you want to show how class D falls right flat on its face, show a 10KHz input waveform and the same 10KHz output waveform **at the same amplitude** of two example amplifiers. Make sure the outputs are shown at the same amplitude as well. Doing what you've done here is not just sloppy, its looks deceitful as well.
Well I just picked up a used Spectron MKII to drive my .7's Maggie's. This class D amp was designed my John Ulrick and who was co founded of Infinity with Arnie Nudel back in the late sixties. This amp is a beast and weighs 52lbs! Has all kinds of power and with do 65 amps fo 500 milseconds when needed. The pre I use with it is the VAC LS 15 and I think it's a very good match. Songs that I've listen to for years now have a intensely close to a live event that I've never heard before. At first I thought it was a little on the anilitical side, but now my Maggie's are projecting more inner detail with the proper energy and now I'm thinking at least to my ears anyway very precise and accurate would be more fitting.
Actually Georgehifi, YOU made the claim the the output of Class-D is not recognizable, and then you compared the switching residue internal or external,
Go back and read a bit more carefully, please🤦♂️.
If the Class-D output filter is removed, then "input test signal" (not switching noise as you say) is not recognizable at the output terminals because of the switching noise monsters it. With the filter in place, it still sad with residual switching noise, but recognizable, as to what’s going into the input.
I recently purchased a used Belles 150A V2 for my second system and I’m amazed at the sound. The rest of the kit is a Luxman C-300 pre, Cambridge Audio CNX V2 streamer, Ryan R620 speakers and Clear Day double shotgun speaker cables and Silnote Audio Morpheus Reference classic interconnects. Every time I listen I have a smile on my face. I never thought class D could sound like this after all the negatives I’ve heard...they just haven’t heard the “right” class D equipment I guess.
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