Hypex NCx500 Class D Amplifier Review

[goryu]

You may not like his tradeoffs but does not mean it is a bad design.

Bad for my situation.

 

[Julf]

At the end of the day it comes down to the same old same old. Continuous compliant ratings vs advertising headline numbers in order to sell product.

Until we get back to genuine, full rated bandwidth, continuous, all channels driven power ratings, this type of PSU undersizing and mismatching will continue in the assembler space.

I am OK with products that take account of reality of peaks vs. average in our source material.

 

[Rick Sykora]

Bad for my situation.

Perhaps as it is more complex than it might otherwise be. Amir’s efforts have helped me but it does seem more complicated for those who really do care. On the other hand, if you put in the effort to understand how design tradeoffs are being made, those tradeoffs have introduced some better price/performance than audiophiles have ever had.

As I mentioned, Hypex (and Purifi) are not perfect but have been more transparent about sharing product specifications than many others. With ATI, NAD and others adopting their tech, it appears to have been a success for them. While it is not a return to traditional values, I think many of us have found the end result beneficial. Hopefully, it will improve as more Class D technology is applied and refined.

 

[boXem]

On this site, people do not look at the DAC chip datasheet to determine the finished DAC performance. Most do not even know the chip used. And that is fantastic.

I do not understand why it is different for power amplifiers using one or more standard bricks. Even more surprising is that when an amplifier using a standard brick supposed to have great performance shows obvious integration issues when measured it keep being recommended by many.
If somebody has an explanation for this, I am very interested.

 

[Rob Fens]

I don't see a problem, why should the psu completely match the capacity of the power amp board? As explained by others these are design decisions.
People totally accept the possibility of choosing between engines when buying a car. As long as manufacturers are transparent about their design choices it seems OK to me.
The manufacturer designs based on choices about factors of quality, cost, durability and customers taste, the buyer decides based on their expectations.
As development of Class D goes on, there will be many more new choices also in the same series (see also Ucd), so there will be more opportunity to balance psu-amp.
All new types start with a limited choice.

 

[Sokel]

What would be real-life,useful,practical and beneficial for the community explanation is someone of the experts here describe what happens when a PSU reaches it's limits.
Not a over-technical report,just the facts of what someone would deal with in such an (edge) case.

 

[Julf]

What would be real-life,useful,practical and beneficial for the community explanation is someone of the experts here describe what happens when a PSU reaches it's limits.
Not a over-technical report,just the facts of what someone would deal with in such an (edge) case.

That is easy to explain. The PSU just isn't capable of maintaining the rated output voltage, so the amp also won't be able to produce the full rated power. If you try to force it to do that, what you get is basically (temporary) compression - or "soft clipping" as the tube aficionados call it. Nothing dramatic, no magic smoke escaping.

 

[Sokel]

That is easy to explain. The PSU just isn't capable of maintaining the rated output voltage, so the amp also won't be able to produce the full rated power. If you try to force it to do that, what you get is basically (temporary) compression - or "soft clipping" as the tube aficionados call it. Nothing dramatic, no magic smoke escaping.

That's what everyone here (hopefully) knows.
As we know the way they clip (by Amir's charts).

I was just hoping for a more technical (but not too much) descriptions of the side-effects (I know some,just want some rock solid confirmation by people who know exactly what they're talking about).

 

[Julf]

That's what everyone here (hopefully) knows.
As we know the way they clip (by Amir's charts).

I was just hoping for a more technical (but not too much) descriptions of the side-effects (I know some,just want some rock solid confirmation by people who know exactly what they're talking about).

What side effects do you think there are?

 

[Sokel]

What side effects do you think there are?

I don't like assuming or replicating scattered info ( think we're all full of it),hence the request to knowledge,skill or experience which some members here have.
General info is nice,but what's valuable about ASR are these exact members who can dive a little more in,not just replicating stuff, and gives us a little more insight.

 

[Julf]

I don't like assuming or replicating scattered info ( think we're all full of it),hence the request to knowledge,skill or experience which some members here have.
General info is nice,but what's valuable about ASR are these exact members who can dive a little more in,not just replicating stuff, and gives us a little more insight.

Problem is that it sounds like you are assuming some side effects, and not accepting an answer that doesn't confirm your expectations.

 

[Sokel]

Problem is that it sounds like you are assuming some side effects, and not accepting an answer that doesn't confirm your expectations.

Oh,that's your problem,not mine,I already said I hate assuming (and I have no expectation unless I pay for it).
Replicating random stuff works like a broken phone,sometimes strips down info that are not so popular or convenient,depending on the narrator.

Hard truth on the other hand is liberating,even if it doesn't suit us all the time.

 

[Julf]

Oh,that's your problem,not mine,I already said I hate assuming (and I have no expectation unless I pay for it).
Replicating random stuff works like a broken phone,sometimes strips down info that are not so popular or convenient,depending on the narrator.

Hard truth on the other hand is liberating,even if it doesn't suit us all the time.

I gave you hard truth. You don't seem to accept it. Curious to hear why, if you don't have any assumptions/expectations.

 

[Sokel]

I gave you hard truth. You don't seem to accept it. Curious to hear why, if you don't have any assumptions/expectations.

That was some hard truth we all know,almost intuitive.Is diving deeper so wrong?
I'd take numbers instead any day of the week.And when it comes to numbers I take no prisoners.

Not even myself,here's some WHOLE system of mine measurements (along with a gazzilion others in the same thread and others),newbie ones but still,can you saw me some of yours?
Devices are to serve us,or else we have a beautiful recycle bin near by if they don't prove themselves up to the task.

 

[Julf]

That was some hard truth we all know,almost intuitive.Is diving deeper so wrong?
I'd take numbers instead any day of the week.And when it comes to numbers I take no prisoners.

Not even myself,here's some WHOLE system of mine measurements (along with a gazzilion others in the same thread and others),newbie ones but still,can you saw me some of yours?
Devices are to serve us,or else we have a beautiful recycle bin near by if they don't prove themselves up to the task.

Well, you asked for a "real-life,useful,practical and beneficial for the community explanation". What numbers do you want?

You asked for an explanation. Not sure what measurements you want from me. I also don't see how your measurements relate to power supply capacity.

 

[Sokel]

Not sure what measurements you want from me.

The ones that shows the sequence (electrically,on the inputs of a speaker) that follows when a PSU runs out of juice.
What remains the same,what changes,potential hazards (other than the obvious,evaporating stuff),owns PSU's further durability,thermals,etc.

 

[Julf]

The ones that shows the sequence (electrically,on the inputs of a speaker) that follows when a PSU runs out of juice.
What remains the same,what changes,potential hazards (other than the obvious,evaporating stuff),owns PSU's further durability,thermals,etc.

"Sequence"? Do you mean consequences? You stated that we all know what happens (electrically,on the inputs of a speaker), so I assume no measurements are needed to demonstrate the compression/soft clipping.

A smaller PSU produces less heat, so overall thermal issues are minimal. The effect of degree of load on SMPS durability is a complex issue and really depends on the design and component choices - I don't think any of us have any reliable data on that for the Hypex SMPS:s.

 

[Sokel]

The effect of degree of load on SMPS durability is a complex issue and really depends on the design and component choices - I don't think any of us have any reliable data on that for the Hypex SMPS:s.

Ok,now we start talking.
That's what I would expect to dive in,these complex issues.
And the word is right,sequence,the events following the change of the normal behavior of a component (other than the straight line of the top of the clipped waveform).
For example @pma has explored various complex issues much deeper than the obvious presenting lots of measurements.

That's the kind I'm talking about and I don't really care if it's an SMPS or linear or anything else.
It will be a nice way to decide between implementations,peace of mind is priceless.

 

[Julf]

Ok,now we start talking.
That's what I would expect to dive in,these complex issues.
And the word is right,sequence,the events following the change of the normal behavior of a component (other than the straight line of the top of the clipped waveform).
For example @pma has explored various complex issues much deeper than the obvious presenting lots of measurements.

That's the kind I'm talking about and I don't really care if it's an SMPS or linear or anything else.
It will be a nice way to decide between implementations,peace of mind is priceless.

So what component changes its "normal behavior" in the SMPS?

 

[Sokel]

So what component changes its "normal behavior" in the SMPS?

No specific component change (it's not like seeking resistor's ppm,nice ones already state this),behavior change,from the PSU as a whole (I describe the whole PSU as a component of an amp).