Do class D amps sound different?

[ThisBass]

Thanks Andy...that I understand!! You know I almost always get it if someone is just willing to tell me twice.

Next lesson will be how alternating current reverses direction without running into itself regardless of where in the circuit it is and what device it's connected to...

The AC current on its own which is (almost always) measured as moveable electrons for a conductor can be considered as nothing but the thermal losses caused by (slow) electrons AC movement.
The transfer of electric energy is a totally different animal. The transfer of electrical energy from source to sink is described by the Poyning vector which is the vector cross product of ExH (vector E x vector H).
For AC the stored (and transfered) energy is periodically stored in magnetic H field and electric E field.
For 60 Hz AC this means that the total stored (electrical) energy ist partially stored 60 times per second in the H field and 60 times per second in the E field (Maxwell equations).
The electrons of an electrical conductor move with rather slow speed) periodically foreward and backward (caused by the AC) but, the electrical energy is stored outside the conductor in the E and H fields.
The inside of a conductor can't carry neither E nor H fields so the inside of a conductor can only "transfer" thermal losses caused by the AC movement of the electrons.

However, without the electrons it was not possible to transfer any LF AC energy in the narrow "outside" environment of a conductor.
Interestingly the ExH transfer of electrical energy does NOT interfer with another ExH
That's just the same like a light wave does not interfer with "another" light wave, or RF wave does never interfer with another RF wave.

edit,
interstingly RF waves (in free air or in vacuum) show similar "dispersion" respectively directivety like acoustcal waves. And its also very impressing that for LF consideration the electrons of a conductor help to transfer energy targeted from a source to a sink.
Light waves belong to the family of electromatic waves (like the 60 Hz AC waves coming off the wall) but, for light wave its possible to transfer the wave with fiber optic cables which (of course) don't provide moveable "electrons".
The main difference of fiber optics cable mechanism versus an LF electrical conductor can be roughly explained this way. While a fiber optic "reflects" the wave inside the conductor an LF "electrical" condurctor reflects the wave "outside" the conductor.

 

[xnewyorka]

The AC current on its own which is (almost always) measured as moveable electrons for a conductor can be considered as nothing but the thermal losses caused by (slow) electrons AC movement.
The transfer of electric energy is a totally different animal. The transfer of electrical energy from source to sink is described by the Poyning vector which is the vector cross product of ExH (vector E x vector H).
For AC the stored (and transfered) energy is periodically stored in magnetic H field and electric E field.
For 60 Hz AC this means that the total stored (electrical) energy ist partially stored 60 times per second in the H field and 60 times per second in the E field (Maxwell equations).
The electrons of an electrical conductor move with rather slow speed) periodically foreward and backward (caused by the AC) but, the electrical energy is stored outside the conductor in the E and H fields.
The inside of a conductor can't carry neither E nor H fields so the inside of a conductor can only "transfer" thermal losses caused by the AC movement of the electrons.

However, without the electrons it was not possible to transfer any LF AC energy in the narrow "outside" environment of a conductor.
Interestingly the ExH transfer of electrical energy does NOT interfer with another ExH
That's just the same like a light wave does not interfer with "another" light wave, or RF wave does never interfer with another RF wave.

edit, interstingly RF waves (free air or vacuum) show similar "dispersion" respectively directivety like acoustcal waves. And its also very interestingly that for LF the electrons of a conductor help to transfer energy targeted from source to sink.
Light waves belong to the family of electromatic waves (like the 60 Hz AC waves coming off the wall) but, for light wave its possible to transfer the wave with fiber optics which (of course) don't provide moveable "electrons".
The main difference of fiber optics cable mechanism versus an LF electrical conductor can be roughly explained this way. While a fiber optic "reflects" the wave inside the conductor an LF "lectrical" condurctor reflects the wave "outside" the conductor. That's the main reason why fiber optic cables can't transfer lots of energy

Yeah, but can you say that fast three times? ;-)

 

[Al Kraft]

That's just the same like a light wave does not interfer with "another" light wave, or RF wave does never interfer with another RF wave.

I was under the impression that under certain conditions different light or RF waves actually can interfere with each other.

 

[ThisBass]

I was under the impression that under certain conditions different light or RF waves actually can interfere with each other.

For vacuum medium shurely its not. For atmospheric free air environment it might be possible the polarisation of the medium might cause interference artifacts.

In atmospheric environment any RF wave does not travel with speed of light any more and phase response versus frequency isn't a linear function which does cause artifacts for group delay.
I have to admit that I do hard to consider how the mechanism of interfering of two "independent" RF waves really works but, can't exclude the artifact for "free air" cause the RF travels in an environment that can be polarized more or less, even by distinct weather conditions that can tarnsih the RF.

 

[ThisBass]

Yeah, but can you say that fast three times? ;-)

At least I had to read three times to understand the meaning of your words.
I think in rough words explained, there is no need to understand the science in total meaning but, once its acceppted the energy is stored outside the wire rather than inside the wire then it might help to better understand WHY there is NO need for 12AWG or 14AWG with generic MI bass amplifiers. No matter if the amplifier is rated with "serious" RMS watts.
16AWG at 1/2 duty cycle is more than adequate to predict negligibly thermal loss for wire of a short length. And as a 16AWG wire don't heats up over time there is no need to complain bad speaker damping with 16AWG.
And if I was a nitpicking I'd rather claim that players in Texas or Arkansas suffer on more average degraded speaker damping versus average players in the northern states.

 

[Old Garage-Bander]

Thanks Andy...that I understand!! You know I almost always get it if someone is just willing to tell me twice.

Next lesson will be how alternating current reverses direction without running into itself regardless of where in the circuit it is and what device it's connected to...

Easy. When it reverses, it's not in the same place as it was before it reversed.

That's why I am an electronics "expert."
I know enough to completely confuse someone else and also look like a fool, all at the same time.

 

[agedhorse]

Easy. When it reverses, it's not in the same place as it was before it reversed.

That's why I am an electronics "expert."
I know enough to completely confuse someone else and also look like a fool, all at the same time.

You have to go and bring hysteresis into the discussion...

 

[ThisBass]

Next lesson will be how alternating current reverses direction without running into itself regardless of where in the circuit it is and what device it's connected to...

May be I suffer on a language barrier? Hope the question is arbitrary. I did regard your words as a very serious consideration about the movement of electrons. That's the reason I did the science related post

 

[Old Garage-Bander]

May be I suffer on a language barrier? Hope the question is arbitrary. I did regard your words as a very serious consideration about the movement of electrons. That's the reason I did the science related post

Either way, I liked you explanation.
I spent some time this summer trying to wrap my head around both E&H fields and near and far fields for microwaves. Then I discovered that near fields were further divided into two seperate regions.

 

[Al Kraft]

May be I suffer on a language barrier? Hope the question is arbitrary. I did regard your words as a very serious consideration about the movement of electrons. That's the reason I did the science related post

...and I very much appreciate you taking time to do that. I'll also freely admit that your English puts my German to shame, so if this were a German forum I'd have a much bigger problem than you seem to.

As a mechanical engineer I never really developed a good intuitive sense when it came to electronics or electricity beyond some fairly fundamental stuff. My question that you so kindly provided a lot of fine insights on was more about me making a joke about myself than trying to pose a genuine question. While I find AC a little weird compared to DC, I actually studied quite a bit on electrical power generation back in the 70's when I got my degree.

Agedhorse and Passinwind both know I'm barely able to understand their answers even when they water them down. I make no pretense at being smarter than I am and just enjoy the opportunity to learn from the incredibly knowledgeable people on this forum. I consider it a good day when I'm able to ask an intelligent question.

While there are some technical areas where I would be considered an expert, the scientific and engineering fields discussed here are sadly not among them. Thanks again for your thoughtful post.

 

[seamonkey]

thermal losses caused by (slow) electrons

Now that's a new one to me Maybe "slow" isn't the right word?
There's something about electrons getting bumped to a higher band, then when they fall back they give off radiation. as Heat, RF, electromagnetic radiation.
And there's the whole discussion if resistors "slow" electron or hole flow.

Traditional current was visualized as hole flow. Look at batteries, and arrows in schematics. They are all drawn as it something comes out of the positive terminal, and heads to the negative. Works either way as long as you're consistent.

 

[bucephylus]

Now that's a new one to me Maybe "slow" isn't the right word?
There's something about electrons getting bumped to a higher band, then when they fall back they give off radiation. as Heat, RF, electromagnetic radiation.
And there's the whole discussion if resistors "slow" electron or hole flow.

Traditional current was visualized as hole flow. Look at batteries, and arrows in schematics. They are all drawn as it something comes out of the positive terminal, and heads to the negative. Works either way as long as you're consistent.

If you cats REALLY want to go off the deep end, ohmic heating generally results from scattering interactions between the charge flow and lattice vibrations and grain boundary structure. If you want to win a big science prize, there is always the phenomenon of electromigration which still lacks a good theoretical basis. I believe the reason for the latter issue is our overly simplified base model for what exactly charge flow in a conductor is.

So, let’s not go there. If you are further interested; please hunt down articles in Physics Rev B, which will probably be unintelligible, even to the highly educated.

 

[Son of Wobble]

If you are further interested; please hunt down articles in Physics Rev B, which will probably be unintelligible, even to the highly educated.

Thanks for the recommendation, but this thread already has me sufficiently baffled.


Bartender, shot of Tort!

 

[Al Kraft]

Thanks for the recommendation, but this thread already has me sufficiently baffled.


Bartender, shot of Tort!

My thanks as well for reminding me that one of the few really good decisions I made in my life was to not major in physics. As Dirty Harry once so eloquently put it, "a man's got know his limitations".

 

[ZenG]

Pffft. Its the cables. Any amp sounds terrible with the wrong instrument cables.

And remember that Class D amps are supposed to be for blues only!!

 

[BadExample]

My thanks as well for reminding me that one of the few really good decisions I made in my life was to not major in physics. As Dirty Harry once so eloquently put it, "a man's got know his limitations".

I like "Are you feeling luck, PUNK?" best. Also can apply to career choices

 

[DigitalMan]

Anecdotally I have run a multi/switchable preamp setup for quite a while. I have run the same collection of preamps driven by both class A/B power amps and more recently class D. The difference between preamps is obvious as you would expect. No two preamps sound the same and they are easy to distinguish. However, the only difference I could tell between the power amps was that the class A/B seemed to generate more audible noise when idle. This could easily be brand/model specific and not a function of architecture.

I have also played a number of the class D heads, and in my opinion they all sound as much different from one another as they do from other class A/B heads.

IMO as long as we are not talking about tube amps, greater than 99% of the difference is in the preamp, and the other 50% is mental.

 

[Passinwind]

Pffft. Its the cables. Any amp sounds terrible with the wrong instrument cables.

And remember that Class D amps are supposed to be for blues only!!

Is Drop D Tuning the new methodology for frustrated geezer techs who can't even read the SMD component labels?

 

[DigitalMan]

Is Drop D Tuning the new methodology for frustrated geezer techs who can't even read the SMD component labels?

Class D amps perform better in drop-testing due to the decreased weight.

 

[Passinwind]

Class D amps perform better in drop-testing due to the decreased weight.

So i need to drop it from a greater height then?