Hypex NCx500 Class D Amplifier Review

[voodooless]

Review and Measurements of Purifi 1ET400A Amplifier

This is a review and detailed measurements of the Purifi 1ET400A Class-D amplifier module. Company was kind enough to send me a complete, assembled kit consisting of two modules, power supply and case, ready to go. They have not disclosed the cost of the unit. Modules will be available to DIY...

www.audiosciencereview.com

Ah, the second set is without the pre-gain stage. Didn't see that, thanks!

 

[boXem]

So it doesn't amplify in low setting it but makes it so the source can't "feel" what mode the amp is in?

If the buffer is bypassed the upstream component has to drive 3.6 kOhm at 14.8 V RMS to reach full power. That is 60 mW.
With a unity gain buffer and a "normal" input impedance of say 100k you need only 2 mW.

 

[Hypexsales]

My issue is testing an OEM supplied building block product, DIY assembled into a box and then pinning it on the so-called "SINAD leaderboard" which is for commercially available and commercially sold products. No prototypes, kit-builds, or bodged-up pre-release circuit boards was the rule. What happened to that?

It's not fair to people like Boxem, March, Buckeye, Apollon etc who build gear we can buy, with (hopefully) realistic specs and usable sensitivity/gain.

If it's just a showcase of the latest Hypex module- test it and discuss it as such. Use disclaimers in the title and make it clear- it cannot be purchased as tested. And now we've got @Hypexsales trying to distort our discussion to suit their narrative.

Disappointing, and not a good look for ASR.

If the SINAD leaderboard is indeed intended for just finished products then yes I agree, please do remove all modules on there. including our NC400, the Purifi module. Just all. We don't make the SINAD leaderboard. that is up to Amir. We don't care. We certainly do not manipulate or try to distort your discusions. We do not appreciate such comments and will prevent us participating such forums. So be carefull were you point your finger to. thanks.

To be clear: as soon as we release a new module, OEM or DIY, you readers and contributors on this forum immediately request test results from Amir. As we have nothing to hide we are more the happy to issue samples to Amir for this purpose. But it seems completely irrelevant to most of you that it is or isn't available for DIY customers. but then complaining the use of the module is irrelevant to normal use case. very strange.

 

[xaxxon]

My issue is testing an OEM supplied building block product, DIY assembled into a box and then pinning it on the so-called "SINAD leaderboard" which is for commercially available and commercially sold products. No prototypes, kit-builds, or bodged-up pre-release circuit boards was the rule. What happened to that?

It's not fair to people like Boxem, March, Buckeye, Apollon etc who build gear we can buy, with (hopefully) realistic specs and usable sensitivity/gain.

If it's just a showcase of the latest Hypex module- test it and discuss it as such. Use disclaimers in the title and make it clear- it cannot be purchased as tested. And now we've got @Hypexsales trying to distort our discussion to suit their narrative.

Disappointing, and not a good look for ASR.

I agree. It's super interesting data, but the presentation needs to be extra super clear about what it is and it should be segregated from the lists containing things you can buy.

The conclusion IMHO that should be drawn from this for 99% of the readers is "I can't wait til there's a review on a production amp running these"

 

[pma]

No. A wider bandwidth would actually capture all the harmonics and measure them, just as amplifier measuring has done for the last 70 years. 10th harmonic or 200kHz has been the standard forever.

Now, with so much bandwidth-challenged class D gear, which is also full of HF noise, the rules needed to be changed to accommodate their deficiencies. Don't pretend it is anything else.

But it is what it is and I don't lose any sleep over it. But I'm not so naïve as to read any class d 'datasheet' as anything other than painting their product in the best light possible for the ignorant, and glossing over the deficiencies. Seems to be the standard MO for Hypex and others since day one.

We all who are involved in measurements know that any class D amplifier (up to nowadays) has dirty nasty spectrum just above 22kHz and that there is no proof that spectrum components will not intermodulate in tweeters, resulting in audible frequencies. Marketing departments need to demonstrate nice plots so they speak about necessity to limit the measuring BW to 20 or 22 kHz.

 

[voodooless]

I agree. It's super interesting data, but the presentation needs to be extra super clear about what it is and it should be segregated from the lists containing things you can buy.

Then you'd also have to annotate any of the amps that are no longer on active sale.

 

[xaxxon]

Then you'd also have to annotate any of the amps that are no longer on active sale.

You can buy gear second hand. ASR is great for buying used stuff, too.

 

[AudioJester]

If the SINAD leaderboard is indeed intended for just finished products then yes I agree, please do remove all modules on there. including our NC400, the Purifi module. Just all. We don't make the SINAD leaderboard. that is up to Amir. We don't care. We certainly do not manipulate or try to distort your discusions. We do not appreciate such comments and will prevent us participating such forums. So be carefull were you point your finger to. thanks.

To be clear: as soon as we release a new module, OEM or DIY, you readers and contributors on this forum immediately request test results from Amir. As we have nothing to hide we are more the happy to issue samples to Amir for this purpose. But it seems completely irrelevant to most of you that it is or isn't available for DIY customers. but then complaining the use of the module is irrelevant to normal use case. very strange.

Please ignore restorer-john. He does not speak for most of us on this forum and is well known to have an anti- Class D crusade. He "loses no sleep" but is consumed by preaching against an amplifier technology lol. This seems to be going on for years!
I would rather read your inputs/comments about your products. I still have ucd modules running strong all these years later.

 

[voodooless]

You can buy gear second hand. ASR is great for buying used stuff, too.

Sure, but you'll have to be lucky to find some of those products. Some of them are harder to get than an OEM product

 

[amirm]

My issue is testing an OEM supplied building block product, DIY assembled into a box and then pinning it on the so-called "SINAD leaderboard" which is for commercially available and commercially sold products. No prototypes, kit-builds, or bodged-up pre-release circuit boards was the rule. What happened to that?

Your issue is without merit. This is not a prototype. It is a production amplifier. Plenty of companies I am sure will build clones of the configuration I tested. Or they will add their own buffer in which case we will be able to compare.

The SINAD graph simply puts values in context. If you don't like it, don't look at it.

 

[JSmith]

... will prevent us participating such forums.

I believe your interaction and membership with ASR is appreciated by the majority as evidenced by the 162 people who have voted great. I think Amir and Rick made everything quite clear about the status of what was tested and as you say very similar to the DIY NC400 and Purifi results posted as a review here also. I don't think a manufacturer could be any more transparent (pun intended too).


JSmith

 

[Waxx]

@Hypexsales It would still be nice if those NCx boards also come availeble to the diycrowd, now most get Purifi boards as they are availeble and better than what you offer (UcD boards and full kits) on your diy store for their custom builds. Many want a more fancy custom case for their amp and make their own buffer section (with the opamps they want). I know quiet a few projects where they used Purifi or even (inferior) Icepower amp modules just for that, as they were very interested in Ncore amps but could not get them barebone.

 

[Sokel]

they used Purifi or even (inferior) Icepower amp modules just for that, as they were very interested in Ncore amps but could not get them barebone.

Agreed about Purifi or top Hypex for full range but for lows Icepower is much nicer,both power and SINAD (and much-much cheaper).

 

[Vacceo]

Your issue is without merit. This is not a prototype. It is a production amplifier. Plenty of companies I am sure will build clones of the configuration I tested. Or they will add their own buffer in which case we will be able to compare.

The SINAD graph simply puts values in context. If you don't like it, don't look at it.

It is my understanding that your review provides a baseline of what the modules can accomplish. That provides a point of comparison to check the final products of the "box" that NAD, Boxem, McIntosh, Marantz or whomever assambles.

 

[Sokel]

My issue is testing an OEM supplied building block product, DIY assembled into a box and then pinning it on the so-called "SINAD leaderboard" which is for commercially available and commercially sold products. No prototypes, kit-builds, or bodged-up pre-release circuit boards was the rule. What happened to that?

It's not fair to people like Boxem, March, Buckeye, Apollon etc who build gear we can buy, with (hopefully) realistic specs and usable sensitivity/gain.

If it's just a showcase of the latest Hypex module- test it and discuss it as such. Use disclaimers in the title and make it clear- it cannot be purchased as tested. And now we've got @Hypexsales trying to distort our discussion to suit their narrative.

Disappointing, and not a good look for ASR.

Now you're not nice,it's better we have a baseline measurement than no measurement at all.
And I think I saw somewhere that the assembler is a pro,so...

 

[Mulder]

I agree. It's super interesting data, but the presentation needs to be extra super clear about what it is and it should be segregated from the lists containing things you can buy.

The conclusion IMHO that should be drawn from this for 99% of the readers is "I can't wait til there's a review on a production amp running these"

I don´t agree. I find it very clear as it is. Can´t see the problem.

 

[restorer-john]

Now you're not nice,it's better we have a baseline measurement than no measurement at all.
And I think I saw somewhere that the assembler is a pro,so...

• The product is not commercially available and cannot be purchased as is, right now. It is NOT "production gear"*
• The assembler has no plans to sell the item as tested.
• It is not a complete product. It is a few PCBs in a case with no markings, approvals, warranty, specifications or price.
• It is a test mule for a new Hypex OEM module. A module that can only be purchased as part of a product that Amir did not test.

Remember it has been made clear many times in the past...

* Not my term. (see above)

 

[Mulder]

• The product is not commercially available and cannot be purchased as is, right now. It is NOT "production gear"*
• The assembler has no plans to sell the item as tested.
• It is not a complete product. It is a few PCBs in a case with no markings, approvals, warranty, specifications or price.
• It is a test mule for a new Hypex OEM module. A module that can only be purchased as part of a product that Amir did not test.

Remember it has been made clear many times in the past...
View attachment 257428

* Not my term. (see above)

I understand what you mean, but I don´t see the problem. I think it was perfectly clear in the review this was a OEM module. So what?

 

[JSmith]

Topping doesn't make/sell amp modules though for DIY and OEM use... a bit apples to oranges there really, just sayin'.


JSmith

 

[restorer-john]

Look it is what it is.

I appreciate the sneak-peek review, the discussion and the robust discourse. Perhaps I am a purist when it comes to things like this. But it isn't my website and Amir does a pretty decent job all in all balancing the flak from each direction.

Anyway, it'd be boring if everyone agreed all the time.