Audiophiles, generally don't like class D amps!

[egellings]

Yes, an SMPS obviously also has a transformer That’s still not something specific to AB amps though, as you already mentioned.

Some DC to DC converters, called buck converters, do not use a transformer. They use an inductor. There is no isolation, and they are used in low voltage applications sites on PCBs, say near a section that needs 3.3Vdc on a board using 5Vdc everywhere else. Buck converters source voltages lower than their input voltages.

 

[gorman]

I came upon this long discussion after deciding to search before creating a new one... my question was really a basic one:

If Class D produces the results I've seen measured by Amir... why don't all manufacturers use it? Ability to mark up more a more expensive product design?

Currently using a Audiophonics MPA-S250NC XLR to complement my Denon X3800 and I couldn't be happier.

 

[terryforsythe]

If Class D produces the results I've seen measured by Amir... why don't all manufacturers use it?

Class D technology has been evolving. It has not been until recent years where class D amplifiers have gotten really good with modules from Hypex and Purifi. Before that a lot of class D amplifiers were somewhat load dependent, especially with complex loads and most notably at the top of the audible range. Many of the cheaper class D amplifiers still are.

Ability to mark up more a more expensive product design?

That may have something to do with it too.

 

[GXAlan]

I came upon this long discussion after deciding to search before creating a new one... my question was really a basic one:

If Class D produces the results I've seen measured by Amir... why don't all manufacturers use it? Ability to mark up more a more expensive product design?

Currently using a Audiophonics MPA-S250NC XLR to complement my Denon X3800 and I couldn't be happier.

For AVRs, companies have said that it is cheaper to go with traditional Class AB.

For hi-fi, the premium audio has moved into jewelry and wealth signaling. Not unlike mechanical watches and high accuracy quartz watches, different brands have different approaches.

You have statement products such as those from Marantz which are class D, Linn which use SMPS with Class AB architecture, Pass Labs which is class A, and McIntosh which uses autoformers. It will be incredibly difficult to hear differences in blind testing for the most part, and I would argue that even when subtle differences may be audible, you’d find all of those systems to be enjoyable.

If you look at premium speakers from Meyer Sound, Genelec, Neumann, L-Acoustics, Bang and Olufsen, it’s all Class D.

 

[voodooless]

For AVRs, companies have said that it is cheaper to go with traditional Class AB.

Yes, they've basically been using the same amp modules for many, many years, ever optimizing them for cost and performance. If you look at the component count and cost, it's amazing how much performance they get out of these things. And apparently, it's also still cheaper to fit a massive transformer based PSU in an AVR, and not an SMPS, even though copper prices are at an all-time high right now.

 

[egellings]

It might have to do with the size and weight of the piece of equipment. A little handful of an amplifier, however powerful, is not likely to impress the owner as something with a more substantial size and overall appearance. A class D amp is much more complex than an AB one is, so there is more chance for failure due to a high electronic component count. Big advantage for class D is little heat generation that can result in better reliability. Components that run hotter will have a reduced reliability than those run cooler. It can, however, be a tossup, too. Fewer components running hotter vs. many components running cooler. Component count and heat both drive reliability. Take your pick.

 

[Pulkass]

I have class D - 3 Behringer + Crown. Elec x over. Multi amped. Sound breath taking......

 

[chelgrian]

I came upon this long discussion after deciding to search before creating a new one... my question was really a basic one:

If Class D produces the results I've seen measured by Amir... why don't all manufacturers use it? Ability to mark up more a more expensive product design?

Currently using a Audiophonics MPA-S250NC XLR to complement my Denon X3800 and I couldn't be happier.

All pro audio manufacturers do It’s only stuff marketed to consumers which persists with other topologies.

You can perfectly well have hi-fi jewellery with class D you just have expensive casework, linear PSUs and fancy input buffers…

 

[atmasphere]

If Class D produces the results I've seen measured by Amir... why don't all manufacturers use it? Ability to mark up more a more expensive product design?

There is the phenomena of 'it wasn't invented here' that is an influence as well. IME that often holds back advancement...

 

[oleg87]

If Class D produces the results I've seen measured by Amir... why don't all manufacturers use it? Ability to mark up more a more expensive product design?

I think you probably overestimate how much measured performance moves units vs. the marketing story, brand recognition, etc.
"We bought a module from Hypex" is a less compelling story in high-end audio vs. "our golden-eared guru tinkered for decades sprinkling the right herbs and spices on his all-custom design until the music came alive, and it weighs 200lbs so you know it's powerful" for most people looking to spend lots of money on audiophile gadgets.

 

[SoonToBeRetired]

Among the things I don't understand about the class D "revolution" is that I was under the impression that an amplifier's capacitors were important, hence I was impressed with the size and the "thin film" technology of the capacitors in my Rotel RB-1582 Mark II i bought 4 years ago, about as classic an AB amplifier that you can still get for about $2K. But my highly regarded Fosi V3 has tiny capacitors that no one seems to consider. Was all that talk about capacitor quality and their size essentially "snake oil"?

 

[terryforsythe]

Among the things I don't understand about the class D "revolution" is that I was under the impression that an amplifier's capacitors were important, hence I was impressed with the size and the "thin film" technology of the capacitors in my Rotel RB-1582 Mark II i bought 4 years ago, about as classic an AB amplifier that you can still get for about $2K. But my highly regarded Fosi V3 has tiny capacitors that no one seems to consider.

The capacitors in a tweeter circuit, for example, are in series with the driver. In a class D amplifer they are not.

Was all that talk about capacitor quality and their size essentially "snake oil"?

Mostly.

Cost aside, metalized plastic capacitors do measure better than electrolytics in virtually every way other than energy density. But, whether that is audible is a highly contentious issue. There is a thread herein in which detailed measurements are presented that supports the contention that most people will not hear a difference. Even if there is an audible difference, which some people claim, it is extremely subtle.

 

[egellings]

In a class D circuit, the reservoir caps can be smaller because they are being filled at a much higher rate (many times per second) than the caps in a conventional 50/60Hz rectifier circuit (50 to 60 times per second). The bucket doesn't have to be as large in a switch mode circuit as a result of that.

 

[rdenney]

Among the things I don't understand about the class D "revolution" is that I was under the impression that an amplifier's capacitors were important, hence I was impressed with the size and the "thin film" technology of the capacitors in my Rotel RB-1582 Mark II i bought 4 years ago, about as classic an AB amplifier that you can still get for about $2K. But my highly regarded Fosi V3 has tiny capacitors that no one seems to consider. Was all that talk about capacitor quality and their size essentially "snake oil"?

The point of those big caps was to store headroom energy, supposedly, but the real point was to filter ripple out of the power supply. The switching power supplies used in modern designs (whether Class D or not) don't create that 60-Hz ripple in the first place and are much easier to filter.

Oh, egellings already said as much.

Rick "and the big-cap fad was a bit overdrawn, too, even in amps with linear supplies" Denney

 

[DavidM1]

It seems class D has benefited from genuine research and innovation in the last few years. I expect a few years from now big, heavy amps will have gone the way of cassette decks and FM tuners.

It will only take one or two major companies to switch completely and the rest will follow. We are seeing signs already that luxury brands are dipping their toes. At the same time, Topping is edging towards a higher price point for the brand.

 

[Sal1950]

It seems class D has benefited from genuine research and innovation in the last few years. I expect a few years from now big, heavy amps will have gone the way of cassette decks and FM tuners.

It will only take one or two major companies to switch completely and the rest will follow. We are seeing signs already that luxury brands are dipping their toes. At the same time, Topping is edging towards a higher price point for the brand.

I think you underestimate the way some will hang on to the obsolete old tech no matter the superiority of the new.
Look to the cases spending tens of thousands of dollars + on turntables and hundreds more for stamping out recycled hockey pucks only
to listen to 1965 sound quality playback. LOL

 

[Joe Smith]

Room for both... There will always be big, heavy and overblown/overfeatured pieces of equipment so that wealthy people can buy them and have bragging rights. Human nature.

I like simplicity and "compact" things, more and more. Part of getting older, I guess.

 

[Waxx]

I think you underestimate the way some will hang on to the obsolete old tech no matter the superiority of the new.
Look to the cases spending tens of thousands of dollars + on turntables and hundreds more for stamping out recycled hockey pucks only
to listen to 1965 sound quality playback. LOL

There is a big market for that, because of the sound of vinyl that fit's our ears (even if it's not hifi in the strict sense of the word). DIgital has potential to overclass that easely but the loudness war kills that, and that is a big issue for many. I had this discussion with some friend, of which most are dj's, some even relative big names. And they all say the same, digital sound flat and lifeless, and most blame it to overcompression. With vinyl the format itself forces you to keep dynamic headroom or the needle jumps. With digital you can go to almost no dynamic range, vinyl needs about 10dB to be cut clean and be playable.

But that is another discussion off course.

The reason why some stick to other tech than class D is partly because they know the bad noisy class D from the early days and therefor don't trust it (even if that is not the case anymore). For me it was solved with the first Ncore amps, and became cheap in that quality with the receent generation Fosi and Topping amps. Their reliability may still be an issue (with the cheap models), but sound quality is not.

And class AB can do the same, Gainclone type of amps were already great, and with the recent version of class ABH with regulated variable powerrails (like Benchmark) they can even beat most of the modern class D on noise.

The other reason is that they have a cheap to build working system like many receiver builders (that use the same basic amp system for decades now) and don't feel the need to change. They don't feel the need to change as their system is working and good enough for their goal.

And off course you got people who deliberate choose somethig else like tubes or class A, often for a personal preference reason, not always on snake oil myths. I'm into that, i have and use noisy class A and tube amps in some setups, next to Ncore in others. Each has their goal and reason to be used and none of those were very expensive (diy or bought cheap). I know the clean systems also as a regular (professsional) user of Genelec monitors, but i prefer some colouration.

Those snake oil adepts off course also still exist.

 

[Sal1950]

There is a big market for that, because of the sound of vinyl that fit's our ears (even if it's not hifi in the strict sense of the word). DIgital has potential to overclass that easely but the loudness war kills that, and that is a big issue for many. I had this discussion with some friend, of which most are dj's, some even relative big names. And they all say the same, digital sound flat and lifeless, and most blame it to overcompression.

You know the old adage about "a lie repeated often enough".
The loudness war has actually only mainly effected a small segment of genre/recordings but is used for a target by vinyl enthusiasts.
If you do your homework on the releases you purchase, overly compressed recordings are mostly avoidable.
So much music, So little time.

 

[zorox]

I always get a kick out of comments that use adjectives like flat, lifeless, not musical when referring to digital recording and reproduction. Things that are not possible to measure. However, noise and distortion, which is possible to measure, is preferred. Ergo noise and distortion is musical. Weird.