Hypex Nilai 500 DIY Stereo Amp Kit Review

[Ropeburn]

Thanks for the review, always nice to read such a good one.

Looks pretty great, slight quibble over value I suppose. Nice.

I apologise for this question; I should know, or have found the answer.
What is it about class D that gives rise to the elevated distortion > 15kHz?
I don't have a problem with it, and don't think it's an audible issue. More of an engineering / design question for my understanding

It's not really a class D problem, but one of perspective. You look at the rising distortion towards 15kHz, and think it's somehow bad - it isn't. It only looks that way because below that, distortion is so low.

 

[dtaylo1066]

Hypex amps suck. Said no one every. I still use and enjoy a numbr of the older UCD-180AD DIY modules and have about 6 extra in my closet for projects I have never gotten around to.

 

[Sokel]

Why do this amp and some DACs show an elevated noise floor only in the bass area? Never quite understood this. Feedback is more heavy handed on mids on purpose?

Sometimes is the measurement itself, using small FFT size for example.
To get more accurate results down low you maybe have to measure it with larger FFT.

You can also see it in some REW measurements all over, lows often show way higher noise floor than this one down low (to the point that they don't make sense at a multitone) (with an eyeballing this one must be in the '90's as is presented)

 

[doug2761]

Nice to see Hypex continue to push class D forward. I built NC400 monoblocks from their kit a few years ago and they continue to impress me. The NC252 from Buckeye that I bought afterwards has also performed flawlessly. It's really nice to state of the art performance at such low prices. Well done Hypex.

 

[capslock]

Looks like distortion around -85dB at 15kHz seems to be a limit in what is achievable in top D Class amplifiers and it looks like even with increased bandwidths rise of distortion vs frequency is not really going away. Interestingly distortion at 10kHz is pushed lower than on Purifi 1ET6525, but 15kHz is worse. Purifi distortion seems to increasing more gradually with increasing frequencies.

I would really love to see smth like this for high power D Class amp someday.

Still hoping that we are going to see 1et9040 measurements. Probably we’ll see similar picture, maybe distortion pushed couple of dB on highest frequencies.

View attachment 496940

Did a 1ET6525 get tested by Amir yet?

 

[amirm]

Sometimes is the measurement itself, using small FFT size for example.

No FFT is used in that test.

 

[daniboun]

Thanks for the review, always nice to read such a good one.

Looks pretty great, slight quibble over value I suppose. Nice.

I apologise for this question; I should know, or have found the answer.
What is it about class D that gives rise to the elevated distortion > 15kHz?
I don't have a problem with it, and don't think it's an audible issue. More of an engineering / design question for my understanding

The elevated distortion above 15 kHz in Class D amplifiers is primarily due to the following factors:
-Switching frequency
-Output filter (a low-pass filter, is designed to remove the high-frequency switching noise. However, the filter's roll-off characteristics can affect the high-frequency response and introduce distortion.)
-EMI and RFI: Class D amps can be susceptible to electromagnetic interference (EMI) and radio-frequency interference (RFI), which can introduce high-frequency noise

That being said, manufacturers have made significant progress on these points regarding the D-Class.

 

[Sokel]

No FFT is used in that test.

I admit that I don't know how AP is calculating it.

At REW (with a window other than rectangular) or Multitone Analyzer it needs about 256k FFT (just about the same when even measuring single tone, the larger the FFT the better the accuracy, under some point is even ugly)

Example:


512k


128k

So, it's the amp at the review. Strange rise indeed.

 

[capslock]

Sometimes is the measurement itself, using small FFT size for example.
To get more accurate results down low you maybe have to measure it with larger FFT.

You can also see it in some REW measurements all over, lows often show way higher noise floor than this one down low (to the point that they don't make sense at a multitone) (with an eyeballing this one must be in the '90's as is presented)

There are also much simpler reasons: inadequate coupling caps (yes, electrolytics usually) and reservoir caps.

 

[Bob101]

I got an Audiophonics alphabet400 Purifi with comparable measurements and a lot more power for less money. I am EU resisdent, so comparing price may be tricky, but why would I consider this amp?

 

[terryforsythe]

I got an Audiophonics alphabet400 Purifi with comparable measurements and a lot more power for less money. I am EU resisdent, so comparing price may be tricky, but why would I consider this amp?

If you already have an amp with which you are happy, stick with what you have.

 

[Bleib]

If you already have an amp with which you are happy, stick with what you have.

Might be useful info for some

 

[totti1965]

Just replying to a person thinking that this product was designed by BP while it was not. I do not see what the problem is.
It's Purifi with a i, not a y.

Sorry, I thought all the Hypex Designs were made by Bruno and are a bit older. So I thougt, @amirm had had just an older, but still very good construction on the table the day before yesterday...

No doubt, that your boXem -Purifi amps are still 3dB or 4dB better and - the finest amps in the world .
The importance of Speakon-Connection has @amirm shown in both of his tests of the Benchmark AHB2! The item with speakon was indeed a bit better!

 

[Matias]

I got an Audiophonics alphabet400 Purifi with comparable measurements and a lot more power for less money. I am EU resisdent, so comparing price may be tricky, but why would I consider this amp?

Not only Purifi, even within Hypex the Nilai has a tough time compared to their excellent and hugely more powerful NCx500 with similar measurements.

Apollon NCx500ST Stereo Amplifier Review

This is a review and detailed measurements of the Apollon NCx500ST stereo class D amplifier based on Hypex NCOREx NCx500 modules. It was kindly drop shipped from the member and costs 1,090.00€ (US $1,168) with standard opamp. While the case is stamped aluminum, it is a heavily customized one...

www.audiosciencereview.com

 

[perceptionist]

Not only Purifi, even within Hypex the Nilai has a tough time compared to their excellent and hugely more powerful NCx500 with similar measurements.

Apollon NCx500ST Stereo Amplifier Review

This is a review and detailed measurements of the Apollon NCx500ST stereo class D amplifier based on Hypex NCOREx NCx500 modules. It was kindly drop shipped from the member and costs 1,090.00€ (US $1,168) with standard opamp. While the case is stamped aluminum, it is a heavily customized one...

www.audiosciencereview.com

For Nilai money, 1ET6525SA would be my choice today.

Texas Instruments

[td]Tier 1[/td] [td]Purifi Eigentakt 2nd gen[/td] [td]Tier 2[/td] [td]Purifi Eigentakt 1st gen[/td] [td]Hypex NCoreX / Nilai[/td] [td]Tier 3[/td] [td]Hypex NCore[/td] [td]Infineon Merus[/td] [td]ICEpower ICEedge / Conductor[/td] [td]Tier 4[/td] [td]ICEpower HCOM[/td] [td]Hypex UcD[/td] [td]Pascal[/td] [td]Tripath[/td]

Source :
https://docs.google.com/spreadsheet...tDABkWS-MApu7uJjzIGnJ2Elm6Y/edit?usp=drivesdk

 

[terryforsythe]

I noticed that the multitone performance is different below 200Hz between the Nilai Stereo tested for this review and the Nilai Mono tested in Feb. 2023. I am curious as to why that is. Perhaps running both amplfier channels off of one power supply is the issue, or maybe a revision to the design? I don't know.

Here is for the Stereo version at medium gain:

Here is for the Mono version at all three gain settings:

 

[TNT]

Apologies if I'm mistaken but I think the 1K value is about -112dB...?

Your are correct and I'm the one to be sorry.
However, there is a -105 dB component in the scart... and I call that distortion... at what frequency is impossible to decipher - not very scientific...

//

 

[terryforsythe]

Your are correct and I'm the one to be sorry.
However, there is a -105 dB component in the scart... and I call that distortion... at what frequency is impossible to decipher - not very scientific...

//

Looking at the chart, it is very low in frequency, down close to DC. Our hearing is not particularly sensitive to distortion in the very low frequencies. At -105dB, which is less than 0.0006%, it is completely inaudible.

 

[Sokel]

Looking at the chart, it is very low in frequency, down close to DC. Our hearing is not particularly sensitive to distortion in the very low frequencies. At -105dB, which is less than 0.0006%, it is completely inaudible.

You two are talking about this one at -105dB which I highlighted yellow?
That's not DC, that's 1kHz. The chart is at 5k intervals: (Nope, it's not a log chart, scrap that)



You can tell by other reviews which scaling is a little different, like this one:

 

[Multicore]

As with @Ropeburn, I'm confused as to what "timing is so off" means for an amplifier. Are you talking about left or right channel delay? If so, maybe there is something wrong with your system, or your particular amplifier. But, I still can't think of what would cause the right and left channels to be out of sync due to the amplifier itself. Perhaps the gain of the left and right channels are not matched, or you have a bad cable? You may need to troubleshoot your system to find the culprit. I have a Nilai, and don't have any timing issues whatsoever. Indeed, I haven't had timing issues with any amplifier I have owned, but I have had RCA cables go bad - the outer shield coming loose from the connector, probably from being moved around too much over the years. Still, that resulted in noise in one case, and loss of music in one channel in another case, not timing issues.

Looks like @leManu sold the amp in Summer 2023.

Hypex Nilai500DIY 250W Stereo Amplifier

Almost brand new, I assembled it and listen to it for 2 weeks. Can ship to Canada or the US. Asking 1800$ CAD or 1300$ USD. My profile on canuck audio mart: https://www.canuckaudiomart.com/userprofile.php?user_id=104781

www.audiosciencereview.com

I wonder if the buyer participates in ASR. Was leManu's build defective or the system it was in or was leManu hearing things or what? 'Tis a mystery.