Audiophiles, generally don't like class D amps!

[Anton D]

Thank you for the feedback, @atmasphere,
Would you also be kind enough to provide us the manufacturers' challenges in sourcing tubes and supply-side problems within the tube industry?
Will that supply-chain amplify your "borrowed time" statement?

I’d like a list of things that are not on borrowed time!

 

[Chrispy]

I am class agnostic.

Soundcraftsman used to have Class H. Crown has, is it Class “I?”

Whatever works, works.

Absolute statements about any format seem a bit odd.

I do think Class D has honestly revolutionized the hobby. I give it a lot of credit!

Crown has both D and AB amps....

 

[DonH56]

I am class agnostic.

Soundcraftsman used to have Class H. Crown has, is it Class “I?”

Whatever works, works.

Absolute statements about any format seem a bit odd.

I do think Class D has honestly revolutionized the hobby. I give it a lot of credit!

Class H uses a tracking power supply so the output stage rails follow the input signal, reducing power.

Crown makes AB and D ("I") amps. I have not tried to keep up, but AFAIK class I is not formally recognized by any standards body. It is essentially an interleaved class D scheme that allows lower switching frequencies on individual channels that when combined create an output with a higher effective switching rate. I have a vague memory that some big Levinson monoblocks did something similar (@amirm, do you know?) I and others have used a similar scheme in the RF world where achieving switching rates 5x ~ 10x the signal was impractical due to device technology limits.

I participate in several audio fora; some seem to have equal numbers of supporters and detractors, others lean heavily towards class D being audibly superior, and some poo-poo class D for more conventional A and AB designs.

 

[mocenigo]

I am class agnostic.

Soundcraftsman used to have Class H. Crown has, is it Class “I?”

Whatever works, works.

Absolute statements about any format seem a bit odd.

I do think Class D has honestly revolutionized the hobby. I give it a lot of credit!

Correct!

 

[mocenigo]

Crown makes AB and D ("I") amps. I have not tried to keep up, but AFAIK class I is not formally recognized by any standards body. It is essentially an interleaved class D scheme that allows lower switching frequencies on individual channels that when combined create an output with a higher effective switching rate.

Roughly that, yes. https://sound-au.com/articles/137234.pdf
They de facto have the individual “rails” switching less often (statistically, half as much as with a single one) thus reducing the impact of dead time and improving efficiency. I expect that at the zero crossover point they will have more noise, resulting in a kind of class D crossover distortion. It seems like a clever idea for pro applications.

I wonder what the Purifi 9040BA is doing. I doubt it is a simple amplification of two signals in opposition. Bruno Putzeys never chooses the obvious path.

 

[wunderkind]

Maybe most Class D equipment don't look as sexy as the "old school" ones? Guys like shiny blinky stuff.

 

[HarmonicTHD]

Maybe most Class D equipment don't look as sexy as the "old school" ones? Guys like shiny blinky stuff.

They had to be explained that AB vs D has nothing to do with airplane classes. D doesn’t stand for digital. D does not create stair steps in the sine wave. It was a long and painful journey.

 

[mocenigo]

They had to be explained that AB vs D has nothing to do with airplane classes. D doesn’t stand for digital. D does not create stair steps in the sine wave. It was a long and painful journey.

Why? It must be like maple syrup. Grade A is the absolute minimum, and some manufacturers have defined Class AA and AAA. Grade B is already low quality, and skipping directly to D without even mentioning C must mean it is toxic crap!!!

 

[Anton D]

Why? It must be like maple syrup. Grade A is the absolute minimum, and some manufacturers have defined Class AA and AAA. Grade B is already low quality, and skipping directly to D without even mentioning C must mean it is toxic crap!!!

Moody’s!!!

 

[jkorten]

As a manufacturer of tube amps the last 45 1/2 years, I'm of the opinion that tube power amplifiers are on borrowed time. Other than overload character, there's nothing that tubes do that class D can't do as well or better. I'm of the opinion also that manufacturers of traditional A or AB solid state amps are on notice that they will have to get a handle on class D or get left behind.

The exact same thoughts we're running through my head when I started listening to these amps! This is the end of all those other technologies.

 

[bob johnson]

I outside of a tube hybrid amp, I challenge anyone to hear and identify the difference in a reasonable class D and anything A/B . Never seen a blind test by any reviewers, doubt I ever would.

 

[bob johnson]

The exact same thoughts we're running through my head when I started listening to these amps! This is the end of all those other technologies.

personally, second order harmonics are nice for amps connected to musical instruments, but for accurate reproduction no thanks.

 

[atmasphere]

personally, second order harmonics are nice for amps connected to musical instruments, but for accurate reproduction no thanks.

Nearly every amp has some 2nd harmonic. Just so you know.

 

[DonH56]

Nearly every amp has some 2nd harmonic. Just so you know.

And a few more...

 

[andrew]

I don’t frequent a lot of other forums but, setting aside the fringe, my take is that over the past decade the consensus has in fact moved from ‘class D is shrill’ to ‘class D great for subs’ to ‘class D is great for simple speaker’. The point of debate now seems to be about whether Class D is better than monster Class A/B amps, for speakers with complex loads. I’ve go no idea if this is, in fact, a valid concern but this space overlaps with those audiophiles with massive investments in statement speakers / amplifiers and concerns about whether standardised measurements are a true representation of performs with real world loads.

 

[goryu]

I don’t frequent a lot of other forums but, setting aside the fringe, my take is that over the past decade the consensus has in fact moved from ‘class D is shrill’ to ‘class D great for subs’ to ‘class D is great for simple speaker’. The point of debate now seems to be about whether Class D is better than monster Class A/B amps, for speakers with complex loads. I’ve go no idea if this is, in fact, a valid concern but this space overlaps with those audiophiles with massive investments in statement speakers / amplifiers and concerns about whether standardised measurements are a true representation of performs with real world loads.

It becomes a matter of personal taste and preference. There really isn't a debate as debates are fought on facts and when it comes to objective performance, the state of art class d amps are there. People become attached to their tech regardless of how old and out of date it may be.

 

[Svet Angelov]

Put a Hypex module in a shiny silver case with big VU meters.
Give it to your favourite subjective reviewer (chances are that even if they open it, they wouldn't recognize the difference in design).
Watch the veil get lifted when instruments finally get the proper amount of "air"


... I need a beer

 

[Ratfink]

The Trees swaying back and forth make the wind blow!

...As long as I can hear Baby Shark reproduced accurately as possible from the original studio recordings...

...Time to go eat some Vittles and then b#ng Granny!... Weeeellllll Doggie!

 

[jooc]

I don’t frequent a lot of other forums but, setting aside the fringe, my take is that over the past decade the consensus has in fact moved from ‘class D is shrill’ to ‘class D great for subs’ to ‘class D is great for simple speaker’.

One point - to be fair, over the past 10 years class D has come a long way, especially ramping up in power to be able to match a/b.

Previously class D amps had high distortion (especially at high frequencies) and the frequency response could change depending on the connected speaker which resulted in obviously bad sound.

 

[antcollinet]

The Trees swaying back and forth make the wind blow!

...As long as I can hear Baby Shark reproduced accurately as possible from the original studio recordings...

...Time to go eat some Vittles and then b#ng Granny!... Weeeellllll Doggie!

An impressive first post here.