Teardown of IOM NCore Pro PWR Amp

[CRKebschull]

The example in the tear down looks a lot better built than the photos in the review thread. Small enclosures may be cute, but as pointed out by our host, can be the cause of mains interference. Low quality capacitors are a warning. It seems only small players are using the MP series of modules. Amplifiers built by ATI, NAD and Mola Mola are assembled with higher end components. However, I don't know if those Hypex boards are built with better capacitors.

It would be rather inconvenient for the board to fail out of warranty especially considering none of these manufacturers are in the US. [Nord claims to have a US repair center, probably an independent shop under contract.]

Well, here are pics of (one of) my home-built NC400 mono blocks (the Hypex DYI kit).

Turned it off and opened it up just to see what caps it's got.

It should be noted that I built these a few years ago, and that the current SMPS600 PSU is Version 5.

But here I see Su'scon caps as well.

Now, I run these stood on end (or rather, on the side) instead of sitting flat on the shelf, whether that's good for heat dissipatation or not, I don't know.

So far, neither heat (they get warm to the touch, never hot) nor running them 24/7 has been an issue. But these Hypex mono block cases have far more room in them than what's been shown here in the thread for the NC252MP.

 

[maty]

I have a lot of Big electrolytics from EPCOS (TDK aka SIEMENS), with very low ripple (or very high capacity to filter the ripple and very low ESR too

) . And I have two expensive 47.000 uF Mundorf M-Lytics with very very low ripple. And yes, they are the best without any doubt. Boutique, audiophile, expensive... but the BEST .

I changed the "little" EPCOS from the prototype with them:

I read first the incredibly favorable comments by Pinnocchio when he used them in a Canadian DIY class A amplifier.

http://www.quebecdiyaudio.com/t712p...-de-la-bete-construction-par-pinnocchio#16727 [pictures]

http://www.quebecdiyaudio.com/t712p...-de-la-bete-construction-par-pinnocchio#16770

Google says that the Canadian forums does not exist!!! I copied the text from a thread I opened in Audiocircle.

to English with Google:

I let the amplifier work for over a week and a half and listened to lots of music. I wanted to be sure of what I heard. I will also validate with Fab, but so far I “hood” on the sound of my USSA 5!​

​

The power supply in an amp makes all the difference, a huge difference in fact. That’s why you should never be afraid to invest in it. The double bridges of ultra-fast diodes with “soft-recovery”, the Mundorf M-Lytics MLGO condos with low impedance and ripple very high and the layout of the PSU very well done, high quality processors. All that matters a lot. This makes a power supply with lower impedance and a much lower noise in the end.​

​

Result, full of low-level micro-details that were difficult to hear or went unnoticed, improved dynamics, a super silent background (very black) and micro-details that are no longer hidden or washed (washed). It was excellent before but there, as I told Fab, I almost fell off my chair. On some recordings that had a remarkable stage depth, it’s even better, difficult to explain, must be heard. I can stick my ear directly on the tweeter and not even a slight whistling, nothing, enough that sometimes I do not know if the amp is open or closed (I have no switch illuminated forward)!​

​

In short, I am very impressed to hear that with a high quality PSU, the USSA 5 sounds even better. Proof that the PSU is the "bottleneck". ]​

​

J’ai acheté 8 condos Mundorf M-Lytics MLGO 33000uF 40Vdc pour mettre dans mes deux nouveaux PSU pour le USSA 3/5. Un ESR de 6mOhm et Ripple de 11.2A​

Obviously I trust Pinnocchio words for years. I give faith of the great improvement.

PS: about other Mundorf caps (crossover) I can not comment by myself.

 

[CRKebschull]

I have a lot of Big electrolytics from EPCOS (TKD aka SIEMENS), with very low ripple. And I have two expensive 47.000 uF Mundorf M-Lytics with very very low ripple. And yes, they are the best without any doubt. Boutique, audiophile, expensive... but the BEST.

[...]

​

In short, I am very impressed to hear that with a high quality PSU, the USSA 5 sounds even better. Proof that the PSU is the "bottleneck". ]​

​

J’ai acheté 8 condos Mundorf M-Lytics MLGO 33000uF 40Vdc pour mettre dans mes deux nouveaux PSU pour le USSA 3/5. Un ESR de 6mOhm et Ripple de 11.2A​

Obviously I trust Pinnochio words for years. I give faith of the great improvement.

PS: about other Mundorf caps (crossover) I can not comment by myself.

Are you suggesting re-capping Hypex Amp PSUs? Lordy... the NC400 already is the second best measuring amp in Amir's list, and that was a stereo version with an undersized PSU. Probably mono blocks measure even better. What are Mundorf electrolytics gonna do better?

 

[maty]

We were both writing and you have gone ahead and it seems that I mean you, but no. I was referring to this link that was published hours before:

PSUs 101: A Detailed Look Into Power Supplies

-> https://www.tomshardware.com/reviews/power-supplies-101,4193-5.html

[ Besides Japanese manufacturers there are also several US and European vendors that make high-quality capacitors. Probably we won't meet any of the below cap brands inside a consumer grade PSU, at least their electrolytic offerings, but we decided that it still worth mentioning them.

• Cornell Dubilier (USA)
• Illinois Capacitor (Currently owned my Cornell Dubilier)
• Kemet Corporation (USA)
• Vishay (USA)
• EPCOS (TDK company, Germany)
• Würth Elektronik (Germany) ]

 

[CRKebschull]

We were both writing and you have gone ahead and it seems that I mean you, but no. I was referring to this link that was published hours before:

PSUs 101: A Detailed Look Into Power Supplies

-> https://www.tomshardware.com/reviews/power-supplies-101,4193-5.html

Right. =)

So, whether it's audible or not, one could possibly make a case about longevity of lower tier caps.

 

[maty]

I like this SMPS more, with components of great quality!

Nichicon is OK. SMPS != linear PSU. We can save money but not as much as Hypex did!!!

 

[graz_lag]

We call them "nudies" when you take pics of the covers off.

I sold a juice aseptic filling line to Nudie Foods, Australia, are they still in business ? Nice people, indeed.

 

[Julf]

The example in the tear down looks a lot better built than the photos in the review thread

Indeed - this one even has the wires to the speaker terminals correctly twisted.

 

[Julf]

Obviously I trust Pinnochio words for years. I give faith of the great improvement.

Did you have a chance to see if his nose got longer?

 

[maty]

To finish,

We can see the pictures of the Pinnocchio's USSA-5, a DIY class A amplifier, with the Big Mundorf M-Lytics in a diyaudio thread, thanks to xrk971.

https://www.diyaudio.com/forums/group-buys/301682-crc-power-supply-class-amplifier-post5204561.html

Cleared

I have put the image for many to see how a very good diyer, such as Pinnocchio, is much more careful with wiring than many companies.

PREAMPs : AMB α10 + USSPA | LDR3x + USSPA | AMPs: AMB β24 | USSA5 | TGM8 | VZ Audio NS OPS | FC-100 | Modulus-686 |
DACs : Mirand AK4490 + Discrete Output | Speakers : Troels Gravesen ATS-4 | Sagwee LT V3 |

 

[Wombat]

We call them "nudies" when you take pics of the covers off.

In the guitar world it is called 'amp porn'.

 

[Burning Sounds]

It is probably some kind of consensus thing among people who repair gear and such.

For me, there is only one tier: Japanese brands and everything else.

Then surely it's anecdotal evidence and although there may be some truth to it your teardown makes it sound like it's a known fact that these are "lower tier" capacitors. Perhaps something like "what are considered by some (many?) to be lower-tiered capacitors" would be more fitting. Not being pedantic here, but it is ASR after all.

 

[Wombat]

This is a follow up to my review of IOM NCore Pro PWR Amp based on hypex NC252MP. The owner gave me kind permission to take the top off and show what is inside.

There were only four screws that held the lid on. Taking those out allowed ready access to inside of the amplifier (click on the image for larger image):

View attachment 33501​

There is not a whole lot beyond the Hypex NC252MP. Focusing on that, I was disappointed once again to find low-tier Su'scon electrolytic capacitors in the switching power supply where they are likely to fail:

View attachment 33502

Fortunately they are rated for 105 degree C (as opposed to 85) as it should be in this application.

The whole module is firmly screwed into the bottom of the thick case so power dissipation should be reasonable.

I checked the mains wiring next:
View attachment 33503

Happy to see crimped butt connectors and proper grounding to the case which I confirmed using my multimeter.

Likewise, the soldering of the speaker terminals was fine:
View attachment 33504

There were a few solder balls on the bottom of the case which would have been nice to have been cleaned/blown off.

Overall, this is well above what an average DIY person without substantial electronics assembly can do.

The close proximity of the XLR input connectors to the mains input is likely responsible for some of the bleed. Nothing could be done in a case this small though.

Overall, it is a fine assembly job.

I would not be happy with that soldering at the output terminals.

 

[March Audio]

Talking about these caps, Manley, in the new tube preamp? uses a SMPS designed by Bruno Putzeys to them. 300 v and switched at 125 kHz. One year, three revisions and the product is:

View attachment 33522

Cheap Su'scon 105 ºC here too.

Hopefully the new SMPS he/they are designing for PURIFI 1ET400A have better big capacitors!!!

Or perhaps they are perfectly adequate.

 

[March Audio]

Amir, you mean generate far less *heat* (or *waste* far less power)?

One as a product of the other.

They are up to about 90% efficient.

 

[AudioSceptic]

One as a product of the other.

They are up to about 90% efficient.

I'm fairly sure what Amir meant, but he said

So they generate far less power than traditional amps.

 

[March Audio]

I'm fairly sure what Amir meant, but he said

Yes, just a slip of the tongue, badly phrased that's all

 

[SEKLEM]

It is probably some kind of consensus thing among people who repair gear and such.

For me, there is only one tier: Japanese brands and everything else.

I believe ICE uses Panasonic capacitors in their modules.

 

[waltzingbear]

I remember Bruno saying the caps he used in the nCore line were fine in a post on the DIYaudio group forum. I too would have preferred a higher grade.

Remember too that Bruno was "only" ever an employee at Hypex, he is more directly involved in the ownership of the more recent activities. This may or may not have an influence on the parts chosen. Certainly price point does, even (especially?) on DIY products.

Cheers
Alan