Class D vs Solid state vs Tubes

[Pjetrof]

I am always thinking would there be a audible difference.
Between solid state and D class amplifiers.
Objective we can prove tubes vs solid.
A, AB, G, H class if well made and played in their parameters no audible difference.
What about D class?
I m not technically studied enough to explain or understand.
I know and understand the diffrence between tubes and transistors.
But D class is something completely different or not?
Is it right to say that we have to choose now between tube amplifier, solid state(A, AB, G, H) and D class.
or is D class inaudible in comparison with solid state?

 

[DonH56]

You may be confusing implementation with amplifier class of operation.

Tube amplifiers typically operate in class A or AB (I am not aware of a current class D tube audio amplifier though there are class D tube amplifiers for other applications like RF).

Solid-state amplifiers typically operate in A, AB, or D.

Class G is typically a class AB amplifier with power supply voltages that switch among several levels as the input signal level changes.

Class H is typically a class AB amplifier with power supply voltages that track (continuously, instead of switching) the input signal.

Class D uses a pulse-width modulation approach so the output switches rapidly between two levels (much like a delta-sigma DAC or DSD stream). Switching occurs way above the audio band so filtering removes the switching noise leaving an audio-band result.

The vast majority of audio amplifiers today are either class AB or D (as best I can tell). For AB, choose between tube or solid state implementations.

The audible difference with tubes is usually due to their higher distortion and much higher output impedance, making them more sensitive to the speaker's impedance (load).

Here is a Wikipedia article on amplifier classes: https://en.wikipedia.org/wiki/Power_amplifier_classes

HTH - Don

 

[RoyB]

What about Class T......I was just reading it is a modified class D. I use cheap ($20) Pyle Class T "90 watt per channel" 12v amplifiers in boats and RVs. Just for fun, I hooked one up to my KEF 103.2 and Magnapan MMGs...........I had to listen hard to hear the difference from a Cambridge Audio Azur 840 and a Yamaha M45! Only at real high levels, the bass became a little distorted, but only on some songs. With a B&W subwoofer, the sound was actually quite good...Freaked me out a bit....Is my hearing that bad or are $20 class T amplifiers that good?

 

[Gorgonzola]

Ooh, naughty words: "audible difference". You're going to offend some hardcore objectivists with those words.

Probably my imagination, but if you have an active imagination like me, you might here some differences. IMHO, different class D amp sound as different from each other as some class A/B amps do. I've never owned a tube power amp and don't intend to, but I do own a tube preamp -- ands a little tube je ne sais quoi to my Purifi class D amp.

 

[solderdude]

I am always thinking would there be a audible difference.
Between solid state and D class amplifiers.

https://www.audiosciencereview.com/...esting-of-power-amplifiers.20464/#post-679653

 

[egellings]

Class D is switchmode, while the others are all continuous in operation.

 

[MrPeabody]

Ooh, naughty words: "audible difference". You're going to offend some hardcore objectivists with those words. .

Why?

 

[mhardy6647]

Class D amplification (pulse width modulation) is (usually) solid state, but (as has been pointed out elsewhere on ASR in similar discussions) can use vacuum tubes just as well, if one desires.
Early commercial Class D amplifiers, in fact, used discrete transistors (which, again, has been discussed here before).

http://www.vk6fh.com/vk6fh/sinclair x10.htm
http://www.vk6fh.com/vk6fh/sinclairX20.htm

 

[boXem]

...
Several commercial Class D amplifiers, in fact, use discrete transistors (which, again, has been discussed here before)
...

Corrected

 

[jasonhanjk]

Newer class D uses mosfet, to gain it's higher efficiency using mosfet's low Rdson.
It's simpler to produce a class AB amp board then a class D, EMC is a pain.

 

[Head_Unit]

Class T

Class T was essentially a specific variation of Class D patented by Tripath corporation which went out of business later on and bought up by Cirrus Logic. The basic thing I remember was the switching frequency varied to get more efficiency and various other advantages. We studied putting one in a head unit; that never happened (less heat but more RFI). A big outboard amp sounded quite good though as with other amps I'd be hard pressed to describe the difference.
https://en.wikipedia.org/wiki/Class-T_amplifier

 

[Head_Unit]

cheap ($20) Class T...Is my hearing that bad or are $20 class T amplifiers that good?

Don't feel bad https://forums.stevehoffman.tv/threads/denon-vs-parts-express-round-1.984507/
At low power levels a lot of amps are fine. Maybe not exactly the SAME but fine. And why not, decades into their design?