NC252MP (class D) vs. A250W4R (classAB) burst measurements into 4ohm//2.2uF load

[Deleted member 48726]

Uhum, why not consider class J when we now are dropping letters?
(Ah, yes, they do exist. eg Peter Asbeck at UCSD looked into those for a while)

This thread has been focused on D vs A/B, without much analysis on A/B with a reactive load. Other classes, as C, E, F ... are somewhat out-of-scope, aren't they?

//BB

The context is missing on you. Take a closer look at what I'm actually responding to with that post.

 

[Rottmannash]

I don't know Bruno? But if he is the only class D manufacturer I think maybe I should..

He's simply the best.

 

[LTig]

probably a dumb question but if one bi amps a speaker then does that reduce the possibility of running into this problem? Of course the signal continues to flow through the crossover but doesn't it then only pass through either the LP or HP section? There may be problems with my assumption the signal is split in some way as it hits the crossover-hence possibly a dumb question.

That could be possible.

 

[IAtaman]

He's simply the best.

Better than anyone?

 

[Deleted member 48726]

He's simply the best.

Better than all the rest?
Better than anyone?
Anyone you've ever met?

 

[Rottmannash]

Name someone who has designed better Class D amplifier modules than Bruno Putzeys.

 

[IAtaman]

probably a dumb question but if one bi amps a speaker then does that reduce the possibility of running into this problem? Of course the signal continues to flow through the crossover but doesn't it then only pass through either the LP or HP section? There may be problems with my assumption the signal is split in some way as it hits the crossover-hence possibly a dumb question.

Possibility of running into this problem is probably comparable to the possibility of being hit by a meteorite at this point.

 

[IAtaman]

Name someone who has designed better Class D amplifier modules than Bruno Putzeys.

Tina Turner?

 

[Deleted member 48726]

Name someone who has designed better Class D amplifier modules than Bruno Putzeys.

I don't know much about it. I'm mainly interested in this topic because I hope to see complex amplifier testing becoming the norm.

 

[Rottmannash]

Tina Turner?

thank you for getting that reference.

 

[Rottmannash]

I don't know much about it. I'm mainly interested in this topic because I hope to see complex amplifier testing becoming the norm.

my comment was directed at another's post implying possibly poor implementation was present. The amplifier in question was designed at the company Bruno was a primary designer of the module, if memory serves.

 

[BenjaminB]

The context is missing on you. Take a closer look at what I'm actually responding to with that post.

Not at all. You bring in irrelevant PA classes (G,H), for some reason. We can only speculate why.
Fact is, class D PA is nothing new. Further classes down the road (G,H,J ...) doesn't change that.

 

[AdamG]

Oh, but Adam if you could only tell us viewers- what do you drive them with?

Buckeye Nc502mp Hypex Amps. But that’s as far as I am sticking my hand into this thread.

 

[orchardaudio]

A little searching will turn up quite a few power amp reviews. Not all will be online, these were written for the print edition. Perhaps start with the review of the Starkrimson from @orchardaudio since that's a good example of a well-engineered Class D amp.

Thanks for the mention @SIY, here are the links to both the reviews/measurements you did:

Fresh From the Bench: A Tale of Two Class-D Amplifiers Orchard Audio Starkrimson and Purifi Audio Eigentakt EVAL1

Stuart Yaniger examines new amplifier solutions from two disrupting audio companies. Purifi Audio from Denmark, founded by Bruno Putzeys, Lars Risbo, and Peter Lyngdorf, together with a remarkable engineering team; and Orchard Audio, with a product developed from the creativity and...

audioxpress.com

https://drive.google.com/file/d/1dLd9QUK2uSOtCFfTcrix76zSrSVNI9c6/view?usp=sharing

 

[valerianf]

The review of the Starkrimson GaN amp is a model that needs to be followed:
1) Amp test on resistive load and (simulated?) speaker load.
2) Test of the hiss by placing the hear close to the speaker ( a decibel meter would enable quantifying the result).

Only think that is missing is a thermal measurement with the amp at full load.

The Starkrimson amplifier seems to be in the leading class of the measured amps.

 

[damonhill]

True, although pro amps are seldom called on to drive electrostats, or other weird loads.

Electrostats aren't a problem. They are not a 2.2uF capacitor placed directly across the output of an amp.

They have a transformer which creates inductive and resistive components.

Amps should be tested with complex reactive loads, but the tests and conclusions seen in this thread are misleading and not representative of any real world condition.

 

[fpitas]

Electrostats aren't a problem. They are not a 2.2uF capacitor placed directly across the output of an amp.

They have a transformer which creates inductive and resistive components.

View attachment 276887

Amps should be tested with complex reactive loads, but the tests and conclusions seen in this thread are misleading and not representative of any real world condition.

I tend to believe you. Still, it's an interesting topic that perhaps deserves some attention, since our job here is to obsess over measurements

 

[amirm]

As you know, it is an Oxymoron. Everyone (almost) tests with resistors only and when listening, no speaker is a resistor only.

And no one listens to continues sine waves which you used in your testing. And the load you created doesn't match any real speaker whatsoever. You sure you want to keep going this argument?

Remember what I said at the outset. We do this test and then what? What reported audible problem are we catching with it?

 

[IAtaman]

I tend to believe you. Still, it's an interesting topic that perhaps deserves some attention, since our job here is to obsess over measurements

Well, the original premise was interesting in that the amplifier load was presented as a rare but potentially realistic case for a speaker. The more the topic was detailed the more apparent it became that this is not the case. In that regard, the measurements are not really more interesting than connecting your amp to the fridge to see what happens in my opinion.

 

[fpitas]

Well, the original premise was interesting in that the amplifier load was presented as a rare but potentially realistic case for a speaker. The more the topic was detailed the more apparent it became that this is not the case. In that regard, the measurements it is not really more interesting than to see what happens you connect your amp to the fridge in my opinion.

I'm not sure. But now I'm curious how that would sound!