Class D amplifiers. What's the future look like?

Well, 40 years ago, Bob Carver's Cube was Class D wasn't it?

https://www.hifinews.com/content/carver-m-400-cube

My friend Wayne at Harvey's let me know one was coming out of the shop to the used shelf. Like many purchases from that shelf, I didn't need it, bought it just because. Ended up using some inefficient speakers in my office, put that cube in a tight space on a shelf near my head, on for hours, the heat was nearly non-existent,

I also has a Carver AM/FM Tuner with his unique features, and ended up with nothing but respect for his mind.

Point is, here we are 40 years later talking about Class D.

They have been all around us for years, current uses listed on wiki are interesting. Scroll down to uses

https://en.wikipedia.org/wiki/Class-D_amplifier

I imagine my self powered home theater sub with 1000 watt amp is class D, I sit very near it, no apparent heat.

Yet, I am skeptical regarding using Class D in my primary listening setup. I've never heard Class D in a main music system.

In any case, I prefer tubes since inheriting (in 1973) a tube unit made in 1958. I only sold those mono blocks (to Steve at VAS) because they didn't have remote volume and I liked the new to me Cayin's sound as much as them.

If he really prefers his class D amps to tube amps then he fools himself. In any case, he is on this forum for business purposes, whatever he says - remember that

I think this post is off base. Ralph can use any amp he wants in his system but chooses to use his GaN amp — not really sure why he’d be fooling himself. And unlike some others here he never tries to “sell” his stuff here and mainly just provides very knowledgeable and helpful info to folks on the site and most of the time on topics that have nothing to do with his products. Not sure where all this cynicism is coming from.

@elliottbnewcombjr - The Carver amp is not class D. It uses a class G output stage. This is essentially class A/B with multiple supply rails which are switched in based on the signal level, so in most situations, the amp is using relatively low 25v rails. 

It also employs an unusual power supply design where the primary (connected to the mains) is switched using a triac (similar to a dimmer switch) to minimize magnetic core saturation allowing a much smaller transformer to be used. 

This design produced prodigious power for it's size, but was not a particularly good sounding amp (in my opinion). 

Be it class D or similar switching technology, it is the future.  Linear amps of all kinds will become a niche market. The only good thing about that is the great progress that has been made in both quality of the amps, and in understanding what kinds of DSP can be used to provide the euphonic distortions some prefer.  First generation ICE modules were screamingly horrible. Newest Purify very clean. Not to my liking but I can accept the progress. 

Speaking of Carver. I remember when someone said he could not make a SS amp sound like a tube, so to prove it, he made a very good tube amp, and then tuned a SS to be very close.  Not as close as some wanted, but he did make a marvelous tube amp. Silver Seven if I remember. Manley showed us how changing the grid resistor changes the tube sound to be almost SS.  The relevant point is that it is the transfer function, not how you get it. 

jaytor

thanks for the clarification. the patent must have run out, and that technology has not taken the industry by storm.

It did it’s job with essentially no heat in my office, but you are right, I never thought ’this thing sounds great’, just gave me music.

Class D must be low heat, do some of them sound 'great'?

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I know it’s off topic, apologies to OP

a bit more about Carver for anyone who cares:

The Carver tuner got amazing reception and sounded darn good as I remember.

https://www.kenrockwell.com/audio/carver/tx-11a.htm

I’m using the tuner in my vintage McIntosh mx110z tube tuner/preamp. It needs a good signal which I have. Sounds terrific. Most people, past and present have never heard terrific FM.

Richard Modaferri said "there is nothing I could do to make that tuner better". He designed this McIntosh Tuner

https://skyfiaudio.com/products/mcintosh-mr77-mr-77-vintage-fm-tuner-richard-modafferi-serviced-dole