Review and Measurements of Hypex NC400 DIY Amp

[March Audio]

Just noticed a Hypex Ncore amp at Audiophonics that I hadn't seen before. It has no electronic modifications (buffers, etc.) and appears to simply be a "case with two NC250P modules", and a nice dual-mono layout with both Balanced XLR and unbalanced RCA inputs, plus heat sinks (which may not actually be necessary). Rated at 65wpc@8Ω and125wpc@4Ω 10Hz-20kHz THD = 0.006%. (A more powerful NC500P version is also available - 135wpc@8Ω and 250wpc@4Ω 10Hz-20kHz THD = 0.006%.)

The 65wpc Audiophonics amp is available for US$650 - about $100 less than a similar Apollon Hypex amplifier that has only XLR inputs.

And I appreciate that they say "assembled" and not "manufactured" in France.

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I know I have a vested interest here but that is NOT the way to wire a Hypex module.

 

[maty]

About Hypex SMPS1200, just now

https://www.diyaudio.com/forums/vendor-s-bazaar/248996-mosfet-amplifier-module-post5820790.html

by vitalica

Yes, both amplifiers were also tested with Cresnet SMPS.
First One with SMPS from Cresnet sounded better than First One with Hypex1200 / 400 SMPS. For me personally it was an SMPS revelation from Cresnet. I just do not feel the need to use the classic PSU. And all my friends agree with me, it sounds gorgeous.

When switching between Hypex and classic PSU, I always want to stay with the classic. With Cresnet I do not have this desire and I started to use them in all my class AB and A projects. But once again, it is my personal opinion.

I can see big caps of 105 ºC and...

https://www.diyaudio.com/forums/vendor-s-bazaar/281413-audio-smps-units-sale-11.html

With Hypex NC400 maybe you can build a good DIY class D amp, I think.

 

[urfaust]

Im worried, the cresnet is adding "something". It seems the NC400 in monoblocks with the hypex power supplies should be as good as it gets (but really even the stereo config), so why playing with the devil

from their specsheet, the NC250MP (mono) are not too far behind, compared to other non NC400, looks like the best 2nd pick, if you don't need as much power.
https://www.hypex.nl/img/upload/doc/ncore_mp/nc250mp/Documentation/NC250MP_02xx.pdf

It would be great to see some amp based on it tested, although doubtful it would break the 100dB SINAD barrier.

 

[pos]

Reading the spreadsheets in details, and ignoring power considerations (which are system dependent variables), the nc400 and the nc2k are clearly above the rest of the ncore amps (although you would have to add a buffer to the nc2k, and that might worsen a few specs), including the nc500, nc1200, and of course the MP series.

 

[maty]

Im worried, the cresnet is adding "something"...

It would be appreciated if you were not so austere in words, that is, a more detailed explanation

 

[maty]

AUDIOPHONICS PA-M250NC Amplifier Mono Class D NCore 1x250W 4 Ohm, only RCA inputs

https://www.audiophonics.fr/en/powe...-mono-class-d-ncore-1x250w-4-ohm-p-12844.html

AUDIOPHONICS PA-S250NC Stereo Class D Amplifier NCore 2x250W 4 Ohm, RCA and XLR inputs

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

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[ Belle dynamique mais écoute fade et ennuyeuse

Cet ampli est assemblé dans un beau boitier sobre et solide. à l'écoute sur des JBL 4430, avec une digione signature en source, il drive parfaitement les 38cm, normal avec un facteur d'amortissement aux environ de 1000.

Je me suis emballé au départ, séduit par la plage dynamique qui explose tous les amplis de classe A-B. Après 48h d'écoute, repassant sur mon Audio Gd Master 3, je me suis rendu compte immédiatement à quel point le Ncore 250 était fade, trop mat, manquait de détourage sur les voix et les instruments, en un sens "normalisait" la musique, finalement je suis déçu par cette signature plutôt ennuyeuse.

Sur le papier il est redoutable, au niveau émotionnel, il ne m'a pas touché.

Attention : les modules Hypex vibrent en émettant un buzz comparable à un petit néon, émanant du boitier, même l'ampli éteint, il faut le savoir si vous projetez de l'installer dans une pièce par exemple dans laquelle vous dormez. ]

=> AUDIO-GD MASTER-3 2019 EDITION Balanced Class A Amplifier ACSS 2x 250W / 8 Ohm

https://www.audiophonics.fr/en/powe...ss-a-amplifier-acss-2x-250w-8-ohm-p-9712.html

 

[urfaust]

It would be appreciated if you were not so austere in words, that is, a more detailed explanation

What i meant by that is exactly what is described in the review you posted. He doesn't like it because it sounds flat and doesn't add "emotion" or whatever, then prefers the AudioGD instead (coughs). About the buzz, might be du to their implementation? i hope for him this is not just a ground loop (but you never know what people could do, specially with 2 power cables..)

 

[maty]

What you are saying is about the complete amplifier.

My question is about the difference between the Hypex SMPS and Cresnet SMPS in terms of the final sound, if there was.

 

[urfaust]

What you are saying is about the complete amplifier.

My question is about the difference between the Hypex SMPS and Cresnet SMPS in terms of the final sound, if there was.

The Hypex ps already achieves 105dB SINAD, and every other great measurements with 2 modules, it shouldn't limit one module in mono as it apparently does in stereo config, so i wouldn't try anything else untested, you know what you get with the hypex SMPS, it's a known quantity. The Cresnet might be better, same or worse, but he says it sounds different, and it shouldn't as it already put noise and distorsion below 130dB in mono with the Hypex. So i was wondering what is it adding to make a difference (if there s any, because possibly he could imagine things too)

 

[GioF71]

Attention : les modules Hypex vibrent en émettant un buzz comparable à un petit néon, émanant du boitier, même l'ampli éteint, il faut le savoir si vous projetez de l'installer dans une pièce par exemple dans laquelle vous dormez. ]

What? That is something you might want to accept from the cheapest amp.
I would have returned my Nord Acoustics NC502MP if it would be emitting a buzz like a neon light (if I understand correctly the sentence in french).
Luckily, it is completely silent.
I assume the user probably has a defective unit, it cannot be a problem with all the hypex modules per se.

 

[maty]

It will be two or three years that I follow Cresnet SMPS. I have only found positive or very positive reviews. And it uses good components, not looking for cost savings as most companies usually do.

I have not heard either of them, so I can not give my opinion.

That buzz is probably caused by the transformer, as with the ICEPower 1200AS modules. At normal distances it is not appreciated, they say. One commented that squeezing the transformer against the PCB stopped ringing, so ... using one or two plastic clamps may be a solution.

It is what I did with two BIG Mundorf caps as a precaution.

[IMG, link] http://maty.galeon.com/WP-imagenes/...r-prototype-inside-detail-Mundorf-47000uF.jpg

 

[PuX]

any idea on how Hypex UcD modules perform?

NAD C388 (and its less powerful versions) is apparently base on those.

 

[Matias]

any idea on how Hypex UcD modules perform?

NAD C388 (and its less powerful versions) is apparently base on those.

Download their datasheets on the Hypex website. There are AP measurements in them with graphs etc.

 

[Dominic]

I have just installed 2 NC400 monoblocks. I have an issue now where my monitor controller, causes one of them to click when I unmute.

The controller does not do this on other amps, and also I tried swapping them round, changing power, wire, xlr etc, but the same block does this annoying click with the mute button.

Any ideas? Its a new issue for me which I never had, thanks for any advice!

EDIT: I should also mention I purchased them used but they seem in mint condition

 

[Julf]

I have just installed 2 NC400 monoblocks. I have an issue now where my monitor controller, causes one of them to click when I unmute.

By "controller", do you mean preamp/source? Any pics of how the monoblocks are wired internally? Are they DC coupled?

 

[Sal1950]

I have just installed 2 NC400 monoblocks. I have an issue now where my monitor controller, causes one of them to click when I unmute.

If it's only a simple single click when unmuting I wouldn't stress over it too much.
There's a ghost in the machine.

 

[VintageFlanker]

Nice!
Here one with a single NC122MP board:
https://www.audiophonics.fr/en/powe...ower-amplifier-ncore-2x75w-8-ohm-p-12756.html
I'll be recomending it to friends. Nothing comes close for this quality at such a low price.

I received mine last week from @Audiophonics. Very clean little power amp, goes all the way to the max power (datasheet gives 1.17V input fo it) without audible distortion. Excellent pairing with my ADI-2 DAC.

I liked it so much that I immediately ordered two PA-M250NC (NC250MP) instead!

I wanted more power for my 88db/8ohms speakers. By the way, the NC250MP has the lowest THD + N of the entire NCxxxMP line.

@Audiophonics should really send these units (or their PA-S250NC/PA-S500NC) to @amirm for review. Sure, datasheets from Hypex already tell a lot of things, but I would be curious to see how these perform under Amir's testing methodology.

One question remains, though: Is there a way that the unbalanced nature of both PA-S125NC/PA-M250NC (RCA only) downgrade the performance somehow?

 

[waltzingbear]

I'm going to assume you have or can borrow a decent DMM.

Measure the DC offset of the amps and see if it has wandered up in the unit under question.
There is a procedure to adjust the offset, although I don't have access to it at the moment. You can find it , with lots of looking, in the DIY audio forums. Or if you do have too much offset a quick email to Hypex will probably get you the procedure. This also has an affect on the input as well.

By controller I'm going to also assume that this person is using them in a studio situation (standard lingo there) and having a click on one speaker would be an annoyance as one is comparing things, not just straight listening.

another idea since you did not build them and we don't know the past history, check the internal wiring of the inputs and make sure they are the same.

Cheers
Alan

 

[kazsud]

How much better is an AHB2 than NC400 mono blocks?

 

[Julf]

How much better is an AHB2 than NC400 mono blocks?

Why would it be better?