Review and Measurements of IOM NCore Pro PWR Amp

[trl]

Black is a bad idea, not professional implementation.

Cut from the second amp of the original photo.

View attachment 33315


It must be yellow+green.

View attachment 33320

Now you are being too picky.
Some are building wood houses this way, so seems that color blind electricians are the best.

 

[Ron Texas]

This is a highly relevant review as there is a lot of interest in budget priced NC252MP based amplifiers.

@amirm what is the difference in gain between high and low gain, and is the switch the rca/xlr switch or something else?

 

[SEKLEM]

This is a highly relevant review as there is a lot of interest in budget priced NC252MP based amplifiers.

I really like to form factor and feature set of this amplifier. I've been looking for a suitable replacement for a B&K Reference 125.2 S2 for Vandersteen 2Ce Sigs. I'm looking at NC502MP based builds at the moment. What reason, if any, should I look at the NC500?

 

[Ron Texas]

I really like to form factor and feature set of this amplifier. I've been looking for a suitable replacement for a B&K Reference 125.2 S2 for Vandersteen 2Ce Sigs. I'm looking at NC502MP based builds at the moment. What reason, if any, should I look at the NC500?

NC500, beats me. A couple of hundred more and slightly better measurements.

 

[Ron Texas]

A few more thoughts here. I checked the manufacturer's site. The tested version with switchable RCA and XLR inputs is not offered. You can have one or the other, but not both. I agree with @maty that the build quality is not good. I looks like someone put it together in their kitchen with a $4 soldering pen and misplaced their much needed reading glasses. The test results are what I expected, slightly worse SINAD than an NC500. Power at 8 ohm load seemed low at around 150 watts. Did I read something wrong?

 

[Ron Texas]

Thanks amirm! Great to see more Hypex in complete products. I'd love to see how an XTZ Edge A2-300 holds up to this. Hypex vs ICEpower, should be interesting!

This product looks like a great deal at only 400 Euros for a stereo pair. That's less than 2 Emotiva PA-1's. I wonder if there is an input board with gain as the amp ships with unbalanced RCA connectors.

 

[VintageFlanker]

Power at 8 ohm load seemed low at around 150 watts. Did I read something wrong?

Nothing wrong here. The NC252MP provides up to 150W peak (8ohms), exactly as mentioned in the last datasheet and close to @amirm measurements. In that regard, the specs from IOM (200W/8ohms) are wrong: these are from the older datasheet.
Also, please note that the continuous power is rated at only 50W.

I agree with @maty that the build quality is not good. I looks like someone put it together in their kitchen with a $4 soldering pen and misplaced their much needed reading glasses.

I was thinking the same. Between the ugly look and finish and the poor build quality, I don't see the point to get this over offerings from @Audiophonics or @March Audio. Apollon's and Rouge Audio's NC252MP are a bit more expensive, but the build seems way better.

 

[Ron Texas]

Nothing wrong here. The NC252MP provides up to 150W peak (8ohms), exactly as mentioned in the last datasheet and close to @amirm measurements. In that regard, the specs from IOM (200W/8ohms) are wrong: these are from the older datasheet.
Also, please note that the continuous power is rated at only 50W.
I was thinking the same. Between the ugly look and finish and the poor build quality, I don't see the point to get this over offerings from @Audiophonics or @March Audio. Apollon's and Rouge Audio's NC252MP are a bit more expensive, but the build seems way better.

Well, I know there are two datasheets. However, some of those making NC252MP amps are claiming 200W at 8 ohms. I'm don't know where you get the 50w continuous spec from, perhaps you could point me to the source. It's a huge jump from 150, not to mention 200. [If the maximum @ 4 ohms is 250, 200 @ 8 seems optimistic, unless the PSU is severely limited.

 

[March Audio]

Yes, I noticed this too. Probably a better cable management and modules position would have avoided this.

If its like the picture Maty showed there are several reasons it might pick up mains 50/60Hz

Also there is a very good reason to not have RCA inputs on the amp.

 

[March Audio]

Yes, easy to view. The black cable (ground), the module turned 180º, unprofessional. It seems that we are seeing a picture of a DIY product. The 252MP uses the same box and I do not see any ventilation holes or additional heatsinks.

https://www.audiophonics.fr/fr/recherche?search_query=hypex+mp

-> https://www.audiophonics.fr/en/powe...s-d-amplifier-2x500w-4-ohm-ncore-p-13344.html

NC500MP x2

We can tune the wiring, try with a RF/EMI Schaffner, thicker top cover and... The important thing is that we have a better starting base than in the previous one.


NC250MP x2

https://www.audiophonics.fr/en/powe...s-d-amplifier-ncore-2x250w-4-ohm-p-13545.html

How many times Maty?

Bruno the designer of the module has pointed out good reasons why not to use a mains emi filter.

Most of the emi is already in the case due to the switching supply and switching amp. Thicker case won't make a jot of difference to this.

It's tiresome to have you repeatedly say this in every thread when you have received explanations multiple times why it isn't so.

Please desist

 

[March Audio]

Nothing wrong here. The NC252MP provides up to 150W peak (8ohms), exactly as mentioned in the last datasheet and close to @amirm measurements. In that regard, the specs from IOM (200W/8ohms) are wrong: these are from the older datasheet.
Also, please note that the continuous power is rated at only 50W.
I was thinking the same. Between the ugly look and finish and the poor build quality, I don't see the point to get this over offerings from @Audiophonics or @March Audio. Apollon's and Rouge Audio's NC252MP are a bit more expensive, but the build seems way better.

I thought I would clear up the power information. I have just tested one to confirm.

The NC252MP provides 150w RMS into 8 ohms (well its really average as pointed out elsewhere) NOT peak.

Output voltage reached 35.2 V RMS (1 kHz) before any noticeable distortion into an 8 ohm load.

I actually think later revisions of the board have had the PSU voltage dropped as my recollection of testing this (it was a very long time ago) that it was higher. That wont affect the lower impedance ratings but limit the high impedance power.

The 50w continuous is in the datasheet but its not clear under what conditions it has this stated limitation. It really doesnt make a lot of sense. They certainly can do the 5 min continuous power test (250 W into 4 ohms), which I presented a video of them doing so in another thread. So Im not sure what its about TBH. I should contact Hypex to see what they say.

 

[amirm]

Just a note that my power levels are approximate. The graph has a very sharp bend there and just a bit to the left or right makes a big difference. Also, I eyeball where the hockey stick starts. One can pick different locations for that. Given all of this, my measurements of 125 watts a 8 ohm are reasonably close to 150 watt spec.

 

[VintageFlanker]

I'm don't know where you get the 50w continuous spec from, perhaps you could point me to the source.

Hum. That is really not a job for Sherlock Holmes. Would you please read the datasheet I just linked?

The 50w continuous is in the datasheet but its not clear what conditions it has this stated limitation. They certainly can do the 5 min continuous power test (250 W into 4 ohms), which I presented a video of them doing so in another thread. So Im not sure what its about TBH. I should contact Hypex to see what they say.

Interesting. I was discussing with Rouge Audio by mail and they said that all Ncore specs are always rated peak, then the continuous power are often much lower. (for example: 100W for NC500/500MP/502MP). As you pointed, we don't know under what conditions these are stated.

 

[maty]

How many times Maty?

Bruno the designer of the module has pointed out good reasons why not to use a mains emi filter...

I wrote TRY with RF/EMI fitlers. Sometimes it seems that I should use more rich edition.

I like to check things for myself, hence I bought a cheap second-hand AVR to experiment with it and then apply it to a new one. The problem is that now it sounds great and I have FM Radio to listen to classical music and learn (they have a low quality MP3, despite being public). As long as I do not verify it for myself, I will keep writing try. If I build the only class-D amp that really interest me, PURIFI 1ET400A, I will do the test. If there is or does not improve, I would tell in ASR, even if there were those few..

If it does noy need it, much better, we save our money!

 

[maty]

Hum. That is really not a job for Sherlock Holmes. Would you please read the datasheet I just linked?

Interesting. I was discussing with Rouge Audio by mail and they said that all Ncore specs are always rated peak, then the continuous power are often much lower. (for example: 100W for NC500/500MP/502MP). As you pointed, we don't know under what conditions these are stated.

Yes, Hypex data are ALWAYS power peak and not continous. MARKETING. Many have fallen, for not striving to inform themselves properly. Usually compulsive purchases or reviews that do not inform as they should.

 

[March Audio]

Hum. That is really not a job for Sherlock Holmes. Would you please read the datasheet I just linked?

Interesting. I was discussing with Rouge Audio by mail and they said that all Ncore specs are always rated peak, then the continuous power are often much lower. (for example: 100W for NC500/500MP/502MP). As you pointed, we don't know under what conditions these are stated.

They are wrong.

P252 (NC252MP) full power FTC test. 5 mins after an hour warm up at 1/3 IIRC. 250 watts into 4 ohms. Not sure if you can see it but the scope is showing about 32 V RMS

 

[boXem]

They are wrong.

P252 (NC252MP) full power FTC test. 5 mins after an hour warm up at 1/3 IIRC. 250 watts into 4 ohms. Not sure if you can see it but the scope is showing about 32 V RMS

Do you have a carpet in your lab?

 

[maty]

The cheap class-D amps usually are publicity at power peak and... at 10% THD in ebay and other pages. It only matters to sell, not ethics, it is what has been imposed. Merit, work well done, effort is not valued, only the benefits.

 

[March Audio]

Just a note that my power levels are approximate. The graph has a very sharp bend there and just a bit to the left or right makes a big difference. Also, I eyeball where the hockey stick starts. One can pick different locations for that. Given all of this, my measurements of 125 watts a 8 ohm are reasonably close to 150 watt spec.

This is a very pertinent point, I think you measured at 91dB sinad which is 0.0028%

I think we should standardise on a particular value for future power output testing. Its a bit arbitrary what figure to choose, but so long as its consistent Im not sure it matters too much. Personally I think 0.01% is sensible, you need to be into the knee section.

 

[March Audio]

Do you have a carpet in your lab?

Its not a lab. Thats the office. It just happened to be convenient to do the video there for various reasons.

In any case we arent making satellites, clean room conditions not required and no, static is not a problem.