I would be surprised if this was the case. Class D amplifiers are, at their heart, analogue. Analogue in analogue out. The storage media of today might be digital but there are loads of ways and implementations for the D/A process. Either separate DACs, DACs built into a SoC etc, but all need amplification for driving loudspeakers. From a price point of view, it's a lot cheaper to use the in-built DAC of a Bluetooth communications device, and then pair it with a separate analgue in class D amp, than it is to use a separate digital in class D amplifier.
Sound quality is usually worse but the end product is simpler, more efficient and less expensive.
Of course there are some SoCs that don't contain a DAC to which a digital input class D amp makes sense. Some of these are essentially a DAC and analogue class D amplifier on a single chip.
I showed with Sublimed TPA3116D2 how it is possible to get as high quality as SE direct driven 300b. TI has recently developed a new 2.1Mhz technology along with Pure Path, The PCB with the output filters measures 17×16 mm only for TPA6304. In near future , applied for higher power units , will extinct the last watts off the chip amplifiers.
Certainly 1W output power and less.
The bargain bin and toy department is where old designs are recycled over and over again, so I don't expect any circuit innovation there unless absolutely necessary. A couple of years ago my son got a cheap set of walkie-talkies, of which the package proudly said "6 transistors". Now go figure how old that design must be...
For high quality audio, any class D scheme that is continuously oscillating (i.e. all of them at the time) is the switchmode equivalent of a class A amplifier and exhibits no crossover distortion typically associated with conventional output stages. To top that off, a switching element coupled with a decent inductor is vastly more linear than any active component could ever wish to be. Class D designs can and do outperform the best class A out there.
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You may be right , but fact is that audio is a bit more complex than a pile of nice numbers , remember , there is an human brain in the middle of the experience 😉
but it's also a fact that somebody like it different just because it is different or new , fortunately we have the choice , which doesn't mean we are all able to make it without our cognitive bias
what ever happens , the simplest the better , always and for everything , even if some people like , really like , to make it complicated 🙄
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My impression:
Short term, new class D chips will appear but existing class AB chip-amps will still be available. Development costs have been paid and chip-amps still provide a cheap and reliable solution to many uses.
For ordinary car radios, ST still has a huge range of BTL class AB chip-amps. In cars, audio power efficiency is not of importance and these chip-amps have a proven reliability. As said by Abraxalito, below 1W class AB will remain.
Class D uses switch mode techniques, as we all know, and switch mode techniques were developed for power conversion. For higher power levels, audio amplifiers use switch mode techniques in order to reduce heating so more compact and elegant constructions can be made.
Long term, switch mode techniques will remain for power conversion but my guess is that most future audio listening will use sophisticated ear-pods and low-power class A/AB electronic amplifier designs. SmartPhones and ear-pods may already today be the most frequent way of listening to music.
There is an irrational element in using apparatuses that can supply 2x 25W-500W for generating a sound level in bulky speakers that only requires mW in ear-pods. All we get out of the 2x 25W-500W is that we force our surroundings to listen to the same sound though they may prefer to listen to something else. My youth was with BIG speaker constructions. My impression is that speakers sold today are getting smaller and smaller because consumers in general do not accept to use so much space for huge speakers. Our needs for mobility and reduced ability to pay for huge accommodations will also favor compact low-power gear. Thus, my guess is that in the far future most will be low-power class A/AB and sophisticated ear-pods.
As more have already stated before me, audiophiles are a very atypical market segment with very different priorities.
Short term, new class D chips will appear but existing class AB chip-amps will still be available. Development costs have been paid and chip-amps still provide a cheap and reliable solution to many uses.
For ordinary car radios, ST still has a huge range of BTL class AB chip-amps. In cars, audio power efficiency is not of importance and these chip-amps have a proven reliability. As said by Abraxalito, below 1W class AB will remain.
Class D uses switch mode techniques, as we all know, and switch mode techniques were developed for power conversion. For higher power levels, audio amplifiers use switch mode techniques in order to reduce heating so more compact and elegant constructions can be made.
Long term, switch mode techniques will remain for power conversion but my guess is that most future audio listening will use sophisticated ear-pods and low-power class A/AB electronic amplifier designs. SmartPhones and ear-pods may already today be the most frequent way of listening to music.
There is an irrational element in using apparatuses that can supply 2x 25W-500W for generating a sound level in bulky speakers that only requires mW in ear-pods. All we get out of the 2x 25W-500W is that we force our surroundings to listen to the same sound though they may prefer to listen to something else. My youth was with BIG speaker constructions. My impression is that speakers sold today are getting smaller and smaller because consumers in general do not accept to use so much space for huge speakers. Our needs for mobility and reduced ability to pay for huge accommodations will also favor compact low-power gear. Thus, my guess is that in the far future most will be low-power class A/AB and sophisticated ear-pods.
As more have already stated before me, audiophiles are a very atypical market segment with very different priorities.
I have to agree with you on this one. A chip amp is a chip amp regardless of the amplifier class- the process of designing with one isn't too different.
As for larger class AB amplifiers, I don't expect them to be entirely gone for a long time. This kind of thing takes a long time to die out. They are already gone from live sound, with the exception of a few offerings from MC^2 (which is an expensive option anyways).
The advantages of Class D start to become smaller and smaller in a HiFi setting where efficiency isn't as big of a deal. The main killer of class AB in live sound, the massive weight, tends to be more of a selling feature for the home stereo market.
Added to that, the transistors used for class AB amplifiers have other uses. We may have to move towards SMD, but many people will argue that with a little practice SMD soldering is easier anyways. The equipment to do it is no longer outlandishly expensive. Quite honestly, I'd probably prefer to deal with SMD soldering than trying to desolder plated through-holes.
So really, aside from the issue of repair, I think that we mostly will just have to adapt. Our physical construction of amplifiers may have to be altered slightly, however, this need not be a bad thing.
Yes, the way mainstream users listen to music has pretty much gone to bluetooth speakers and earbuds. That said, traditional bookshelf and floor-standing speakers will not be going away any time soon.
Indeed.
Class A stuff is for those who believe it's a better choice for sonics... blah, get real.
Give me real push-pull power for those dynamic transients! - that's HiFi!
My neighbors - mid-late 40's types, have "bought into" the "new" style of sound.
WIFI speakers, portable, etc... with internet streaming music.
I'm sure they're satisfied with that crap.
But when the husband came over, and heard my "all tube" 1963 RCA Victor console - he was totally floored by it, stating "Wow, that's the richest sound I ever heard!"
You can't beat a pair of 12 inch woofers with earbuds.
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Honestly, Class A will always be a niche for those brave enough to put up with it. Still, I think it can sound great if it is well implemented.
There's no "right" way to do this. It depends so much on the application, personal preferences, etc.
While I tend to be a very practical person, mark my words I will design and build a 400 WPC liquid-cooled class A amplifier some day. Yes, I do know how completely ridiculous such a thing is, and I do know how massive of a project it will be. Some people put 1000 horsepower engines in their Chevy trucks, others build really stupid amplifiers. But hey, at least a big push-pull class A amplifier will probably be more efficient than said truck.
There's no "right" way to do this. It depends so much on the application, personal preferences, etc.
While I tend to be a very practical person, mark my words I will design and build a 400 WPC liquid-cooled class A amplifier some day. Yes, I do know how completely ridiculous such a thing is, and I do know how massive of a project it will be. Some people put 1000 horsepower engines in their Chevy trucks, others build really stupid amplifiers. But hey, at least a big push-pull class A amplifier will probably be more efficient than said truck.
Great concept. You could use the fluid to warm up all the rooms in your house and get hot water as well
🙂
Great concept. You could use the fluid to warm up all the rooms in your house and get hot water as well
Well, you know, it would be one of those things that only gets used during the bitter Wisconsin winters...