Nord MP NC252 SE Amplifier Review

[pma]

For this theory to apply pma, presumably you use the reverse?

Yes, exactly. The left channel is closer to the SMPS and the right channel is farther.

 

[Ropeburn]

2.5 milliohm is absolutely unrealistic, if you take into account any wire length. 20 cm of Cu wire pair of 1 mm2 cross section (40 cm total length) would have 8 milliohm resistance. Add contact resistance and you are there. All that race for milliohm output impedance is again a nonsense. Damping factor above 50 or so has no audible effect, other than audiophile fairy tales.

Oh I know, just curious.

Especially since your measurement shows a rise roughly proportional to Hypex measurements:

If 2.3 -> 16 was just wiring, shouldn't it be flatter? Does wiring capacitance/inductance have such influence towards 20kHz?

You're ruining my precious damping factor!!! I specifically made 8AWG cables that theoretically have 6mOhm at 3m (without plugs lol), and your internal wiring has 16!!! Gross incompetence!!!

Funnily enough, new NCx252MP spec (and Hypex measurement) says 0.5mOhm lol!

 

[pma]

Yet we didn't see as much variation as your tests (even though minor) and nowhere near as much as Amir measured in this review, compared to;

I understand what you mean, but please check the relative dB difference between the fundamental and spuriae.

 

[pma]

If 2.3 -> 16 was just wiring, shouldn't it be flatter? Does wiring capacitance/inductance have such influence towards 20kHz?

Inductance. Just calculate, based on length of wires. You may use available on-line inductance calculators. Then calculate R + jwL at 20kHz.

 

[pma]

Why our amplifier measured worse will be revealed when we know for sure, rather than speculating.

What happens if you disconnect your input module and short the inputs at the Nc252mp board? Then measure output noise spectrum? What is the amplitude of spuriae, then?

 

[PristineSound]

I don't find this argument convincing. Amplifiers with an integrated PSU are simply more difficult to repair if they fail. Reliability is more related to the quality of design (components, engineering, heat dissipation, etc.)

Do a search for Apollon Audio's (manufacturer) post. Tibor argues that because it's integrated, failure rate is higher for reasons of heat and shared components.

And to be fair, Buckeye is saying it's reliable from his limited experience.

 

[pma]

Tibor says it depends on manufacture year and that there is a break point. I have tortured my sample since December 2021 and it still holds strong. However, I have an efficient heatsink, as I am sure that it is the key factor. Temperature is the killer.

 

[PristineSound]

Tibor says it depends on manufacture year and that there is a break point. I have tortured my sample since December 2021 and it still holds strong. However, I have an efficient heatsink, as I am sure that it is the key factor. Temperature is the killer.

If you are referring to this, Tibor said 2020, but this post doesn't seem to confirm that versions there after are "bullet proof" as the NC and NCx are.

Hypex NC252MP cautionary tale

But given your experience with a substantial number of units, would you agree that, in general, the MP series modules tend to fail more often compared to the higher-end Hypex modules (like NCx, NC500, NC1200, NC2K) or Purifi designs? If you compare failure numbers between MP and non-MP modules...

www.audiosciencereview.com

 

[Pritaudio]

Can someone refer me to what these new ncx252 or ncx series in general are.
I’ve never heard of them. And when did they start replacing the old ‘nc’ range.
Where can I find discussions.

 

[fullspeed]

Suscon cRapacitors big fail there propably degrade performance.FR or FC panasonics way better for the low esr hi ripple current job.

 

[wwenze]

company suggested that the input switch may have oxidized causing intermittent performance

Time to invest in switches that don't oxidize.

Majority of buyers don't measure what they buy, at least not all the time, and pay money for performance.

 

[Tone]

Time to invest in switches that don't oxidize.

Majority of buyers don't measure what they buy, at least not all the time, and pay money for performance.

They are not oxidised, read the thread please.

 

[Tone]

Can someone refer me to what these new ncx252 or ncx series in general are.
I’ve never heard of them. And when did they start replacing the old ‘nc’ range.
Where can I find discussions.

Mains Powered NCOREx® Family

www.hypex.nl

 

[Matias]

Can someone refer me to what these new ncx252 or ncx series in general are.
I’ve never heard of them. And when did they start replacing the old ‘nc’ range.
Where can I find discussions.

Hypex Announces New and Improved NCOREx Class-D Amplifier Technology

Nice. "The first new module with NCOREx implemented is the NCx500 OEM, and can be used as a drop-in replacement for the existing NC500 OEM module." https://audioxpress.com/news/hypex-announces-new-and-improved-ncorex-class-d-amplifier-technology

www.audiosciencereview.com

 

[Scrivs]

Suscon cRapacitors big fail there propably degrade performance.FR or FC panasonics way better for the low esr hi ripple current job.

Now I have Phil Collins stuck in my head as I get into bed—
Sus’ sus’ sus’con

 

[Tone]

Suscon cRapacitors big fail there propably degrade performance.FR or FC panasonics way better for the low esr hi ripple current job.

Hypex stopped using Su'scon years ago.

 

[Ropeburn]

"These caps are sus"
"Why? They're good ones from Suscon"

 

[Pritaudio]

Mains Powered NCOREx® Family

www.hypex.nl

Which is the model you are using. Ncx252 or nc252.
Because your website product page says nc252.
And are these older versions still available.

 

[hat28]

I think there are four Nord amps reviewed on asr.

Three of those four have had issues:

1. https://www.audiosciencereview.com/...-and-measurements-of-nord-one-nc500-amp.7704/ incorrect wiring

2. https://www.audiosciencereview.com/...-se-1et400a-dual-mono-stereo-amp-review.9938/ amp shipped with incorrect fuse

3. The amp in this review.

Is this to be seen as an incredibly unfortunate series of coincidences, or a reflection on quality control?

 

[DSJR]

Revised my vote up to 'fine' following Nord's explanation and Amirm's re-test

Nagging worries remain over component quality (I don't routinely flick all the switches on my equipment, and wouldn't expect that to cause problems) and the assembly choices. I'm not qualified to assess this myself, but there does seem to be consensus that the layout could/should be better. Otherwise, its a perfectly good amp.

It's a shame for Nord, if they'd submitted a new unit then these issues would probably not have shown up. Now I am, perhaps unfairly, put off the brand. It's a crowded market out there.

Back in Jurassic times when I was working, it was a usual thing to recommend an annual unplug-replug and gently cycle switches for best connection/contact. I'd have put cycling these switches as part of that (power disconnected obviously).

Maybe gear these days is so perfect, that one leaves it totally alone from one year to the next, ignoring humidity in some environments and dust/smoke in others?

Apologies if the above comes across as some sarcasm, but switches do tarnish, relays can wear in some situations (my second-system amp seems to suffer bad speaker relays (more than the headphone circuit one) and I bought said amp very cheaply for all of a fiver's worth of a relay!

I'd not be hard on Nord here. Maybe a different switch type could offer a less fussy lifespan?