Hypex NCx500 Class D Amplifier Review

[pawsman]

I have eyed the IceEdge amps but have plenty of Hypex and a Purifi amp. Reportedly they are a step down in terms of performance but liked the construction and protection features. Would not expect any diff in sound quality and seems like the 1200as has plenty of power. If you are happy, would not change. If you are curious, would take advantage of a trial period on Hypex or Purifi amp.

Thank you for the replies, Rick and Sokel. I'll probably hang on to the 1200as amp, it's been reliable and I have no complaints-

pawsman

 

[RickS]

Here is a sneak peek at Buckeye's 2-channel NCx500. He sent me a unit for testing as I already had the amp modules in stock. So here is a quick look at using the SMPS1200A700 to drive one channel individually and then both channels together (test is 4 ohm load with 1 kHz signal). The unit is set for HIGH gain....

Sorry for the similar colors, but matters less as you can see the results at lower power are very comparable. As you would expect, the medium blue line is the distortion with both channels driven and the other is only one channel. FYI, the free version of REW allows for 2 outputs, but only one input. I did test measure the other channel and they track well. For simplicity, am only displaying one.

As predicted earlier, 1% THD occurs around 600 watts and 700 watts respectively. I plan to post a more comprehensive set of measurements in a new thread.

 

[Sokel]

What it more important than the 1% THD mark is the 0.002% THD mark which is identical,100 watts less (or more,depends from where you see it).

100 watts is a whole old big amp!Absolutely covers the cost for a dedicated PSU.
Even if it's not needed in a current set-up,any future one may need it,as we saw in the other thread power is never a waste.

 

[antcollinet]

100 watts is a whole old big amp

Or only +1dB / close to inaudible depending on how you look at it

 

[Sokel]

Or only +1dB / close to inaudible depending on how you look at it

Sure,inaudible in normal conditions.
But if that 100 watt is the differentiator between clipping or not it can sure be audible (the worst kind of audible,far beyond IMD or anything else).

 

[Matias]

Would be interesting to see if single PS power increases using 220V phase+phase mains with the Buckeye amp too, as seen with the Apollon.

 

[RickS]

Would be interesting to see if single PS power increases using 220V phase+phase mains with the Buckeye amp too, as seen with the Apollon.

I am capable of testing 240 Vac operation but have to build a cable. The rail voltage will be determined by the SMPS and so seems unlikely there would be much difference unless a different SMPS is used. That said…

The UCD700 info in the SMPS data sheet shows a slight increase (to 620 watts) when using at 240 Vac vs 230 Vac. At 120 Vac, the output spec is 600 watts per channel. Since the difference is minimal, guessing Hypex decided not to detail. I do like that Purifi published the output power curves based on supplied rail voltage. @NTK posted them in the Clipping 101 thread.

 

[RickS]

I am capable of testing 240 Vac operation but have to build a cable. The rail voltage will be determined by the SMPS and so seems unlikely there would be much difference unless a different SMPS is used. That said…

The UCD700 info in the SMPS data sheet shows a slight increase (to 620 watts) when using at 240 Vac vs 230 Vac. At 120 Vac, the output spec is 600 watts per channel. Since the difference is minimal, guessing Hypex decided not to detail. I do like that Purifi published the output power curves based on supplied rail voltage. @NTK posted them in the Clipping 101 thread.

…I asked Hypex if they had comparable measurements to show how the NCx500 output varies with rail voltage and they do not have. Given the tech and heritage, would not be surprised if the curves are comparable to the Purifi ones. Probably worth noting that rail voltage is the key rating more so than wattage too. Some of the earlier discussion here was focused on power from the SMPS; voltage is really the driving metric.

 

[SkipperGW]

i'm not an expert when it comes to all these measurements.
but i've noticed differences in those curves and wonder what they mean.

hypex ncx500

purify 1et400a

the hypex curve starts to drop at 10k, whereas the purifi curve starts to drop at 20k.
what does that mean — how does that affect the sound, and which impact does it have on the music?
thank you very much, indeed, in advance for explaining this to this ignorant technical n00b…

 

[Matias]

i'm not an expert when it comes to all these measurements.
but i've noticed differences in those curves and wonder what they mean.

hypex ncx500

purify 1et400a

the hypex curve starts to drop at 10k, whereas the purifi curve starts to drop at 20k.
what does that mean — how does that affect the sound, and which impact does it have on the music?
thank you very much, indeed, in advance for explaining this to this ignorant technical n00b…

Look at the Y axis, and also the cursors on the right. The NCx500 has a tiny -0.267 dB roll off at 20 kHz which is absolutely inconsequential, while it extends -5.0 dB higher than 1ET400A, which is even more inconsequential. These are just 2 flavors of excellent.

Compare the frequency response to cheaper class D amps and you will see large deviations with 8 ohms, these are more significant.

 

[SkipperGW]

thank you!
now, i wonder what that does mean in common people's language?

 

[Matias]

thank you!
now, i wonder what that does mean in common people's language?

In short: NCx500 and 1ET400A are both excellent.

 

[SkipperGW]

thanks again.
so, no difference when it comes to listening…?

 

[antcollinet]

thank you!
now, i wonder what that does mean in common people's language?

The differences are tiny - and make no difference to the sound.

 

[SkipperGW]

thanks a lot!

 

[Julf]

thanks again.
so, no difference when it comes to listening…?

Yes.

 

[Buckeye Amps]

My objective opinion as a dealer: both the Purifi and NCx500 will sound/perform practically identical.
There are those who say otherwise but.....yea I'm not buying it.

 

[Mnyb]

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

Me too if their was a generals agreed upon standard to measure this ?

There nothing inherently wrong with what hypex and purify are trying to spec , the wrong is that single brands take upon themselves to just add their own kind of spec good or bad does not matter. NAD and proton has been up to this to historicaly with some kind of dynamic power spec so it’s not only class D .

There should be standard test signal with the average spectral content and average crest factor of music .
Or we could use red hot chilli peppers or Metallicas death magnetic for worst case scenario

But before there is such a thing these brand should also present thier amps measured by the agreed open standards that exist even if they are not perfect or always relevant, there are the same for all .

A brands own arbitrary spec good or bad takes a whole lot of additional context to even understand.

How do we actually know that hypex specs actually takes into account “ peaks vs average in source material “ because they say so does not really cut it , even if it’s is an honest attempt to actually do this .
The fact that they invented thier of spec methods makes it impossible to compare with others.

Amirs way of trying to measure all amps the same way is good because it’s then possible to compare with other amps measured by him.

Don’t get me wrong i would probably get a good implementation of one of these amps in the future.

 

[Matias]

Fresh From the Bench: The Hypex NCORE NCx500 Amplifier Module - Doubling Down on a Flagship

The new NCx500 amplifier board from Dutch manufacturer Hypex Electronics is the first of a new NCOREx family of modules that evolves from the extremely popular NCORE Class-D amplifier technology, one of the most successful options among high-end audio and studio monitor brands. Stuart Yaniger...

audioxpress.com

 

[Matias]

Another european option of a single PS + dual NCx500 in a pretty chassis, nicely built, for 1.2k euros.

IOM 500 Stereo (NCx500) - high-end amplifier with custom input buffer

The IOM 500 stereo is a powerful amplifier using 2 Hypex NCx500 modules and the SMPS1200A700 power supply.

internetofmusic.nl

Interesting that they offer 2 options of boards: one just connects inputs and outputs (and leave the opamp duties to the ones inside the NCx500 modules); and another option which uses external opamps for users to roll.

Buckeye did something similar but using a single connection board and switching between the 2 modes.

Edit: also interesting to note that the opamp-rollable board uses Hypex voltage regulators, as opposed to Sparkos regulators which is commonly seen with those.