Hypex Nilai500DIY Amplifier Review

[Marc v E]

Since when KEF is made in US?

Are Kef the greatest?

 

[Rick Sykora]

The only circumstance I see myself building a diy amp would be if I need a multichannel one and I don’t find one that fits my needs. The maths are favourable as the price of the box vs the modules gets better, and the fact that hypex diy modules are mono is also favorable, as you can chose the exact number of channels that you need.

What is not that favorable is the size and form factor. 10x10 cm for one channel without power supply the heatsink being the bottom plate? Feels that you need a football stadium to accommodate, say, 6 channels… I see that other hypex diy boards tend to be relatively big compared to their OEM and stereo boards if I am not mistaken.

This is a personal opinion that for sure does not apply to many of the customers for these modules, but I am sure I am not the only one thinking the same, just wanted to bring it up in case hypex reads it

With a case that has tall enough side seems vertically mounting amp modules is feasible but getting full power from them means 6 power supplies. Pretty sure Hypex would be happy to sell it to you, but several vendors are doing vertically mounted NC502MPs which would be far less expensive and more than adequate for home theater use. For that matter NC252MPs are good enough for surround channel power…

If was doing with Nilai, probably would use fewer power supplies and share them for the surrounds. The Nilai amp modules use a different heat spreader and output devices are mounted in the middle. If I was spending the time and money, would consult with Hypex support and get some thermal advice. The new power supplies may have some different consideration as most of the heat appears to being handled topside.

 

[Waxx]

Are Kef the greatest?

One of the top brands at least.

And the top transducers (or speaker drivers) brands, for OEM and DIY are almost all European brands. Scanspeak, Volt, Seas, SB Acoustics, Purifi, Bliesma, B&C, Fane, Beyma, Faital, 18Sound, Kartesian, Tymphany/Peerless, ... are all European brands. Only Altec Lansing/GPA, JBL and it's spinoff TAD is not actually.

 

[lashto]

Nice improvement compared to the 'old' nCore modules. However, those THD vs Freq graphs still look pretty bad.

I know it's ~same for all Hypex & Purifi modules and nowadays it gets marked like "some increase to be expected" but IMO it is way too much.

Those amps go into the SINAD table with scores around 110dB and are considered TOTL/top10 amps but that's only valid at their best 1kHz point. With a 10kHz test signal you actually have a somewhat meh amp (~90dB SINAD) and at 15kHz it's a mediocre amp (~75dB SINAD). 75dB SINAD is not a top10 amp, that is a headless-panther amp in 2020.
But still, many call those amps "perfect" and "amplification was solved". And if anyone complains about harsh/hard highs they get quite a rebuke.

Would be interesting to see some detailed HD spectra with 5/10/15kHz test signals, those are surely not as pretty as the standard 1kHz one.

Hopefully hypex/purifi can do something about it, that measurement still a big no go in my book.

 

[Julf]

Those amps go into the SINAD table with scores around 110dB and are considered TOTL/top10 amps but that's only valid at their best 1kHz point. With a 10kHz test signal you actually have a somewhat meh amp (~90dB SINAD) and at 15kHz it's a mediocre amp (~75dB SINAD). 75dB SINAD is not a top10 amp, that is a headless-panther amp in 2020.

The first harmonic of 15 kHz is at 30 kHz. Can you hear that?

 

[lashto]

The first harmonic of 15 kHz is at 30 kHz. Can you hear that?

Yes I (still) can.
Actually, anyone can hear that. Or more precisely anyone who can hear 15kHz.

You may wanna do a bit of research on those harmonics. You do not hear a 30kHz sound, you hear its 'coloring' effect on the 15kHz fundamental. It's so "bad" that even if you do not play a 15kHz sound but only its harmonics, you will hear only one sound: the 'missing' 15kHz. It's called the missing fundamental effect. There are also youtube demos if you still have doubts.

 

[HarmonicTHD]

Yes I (still) can.
Actually, anyone can hear that. Or more precisely anyone who can hear 15kHz.

You may wanna do a bit of research on those harmonics. You do not hear a 30kHz sound, you hear its 'coloring' effect on the 15kHz fundamental. It's so "bad" that even if you do not play a 15kHz sound but only its harmonics, you will hear only one sound: the 'missing' 15kHz. It's called the missing fundamental effect. There are also youtube demos if you still have doubts.

So you hear 15khz 75dB below the fundamental?

 

[Julf]

Yes I (still) can.
Actually, anyone can hear that. Or more precisely anyone who can hear 15kHz.

You may wanna do a bit of research on those harmonics. You do not hear a 30kHz sound, you hear its 'coloring' effect on the 15kHz fundamental. It's so "bad" that even if you do not play a 15kHz sound but only its harmonics, you will hear only one sound: the 'missing' 15kHz. It's called the missing fundamental effect. There are also youtube demos if you still have doubts.

I am more than familiar with the missing fundamental effect. It only works if you can hear the harmonics. If you can't hear the 30 kHz, you won't hear a 15 kHz missing fundamental either.

I would love to see verified, objective evidence you hear any harmonic distortion from a 15 kHz tone.

 

[lashto]

So you hear 15khz 75dB below the fundamental?

Again yes. Or more precisely, it is not a clear NO: may or may not be audible depending on the test signal, your ears, your equipment etc...

What you hear is the 15kHz at the same dB level. It's 'coloration' (btw, called timbre in musical therms) is not 75dB below, it's at the same level.
Think about it as a very "fade" coloration. A light-waves analogy might be helpful to wrap your head around it. E.g. when combining a Yellow wave with a Infrared wave you will see a red-tainted yellow (even though the infrared wave itself is 100% invisible.)

 

[Killingbeans]

Yes I (still) can.
Actually, anyone can hear that. Or more precisely anyone who can hear 15kHz.

You may wanna do a bit of research on those harmonics. You do not hear a 30kHz sound, you hear its 'coloring' effect on the 15kHz fundamental. It's so "bad" that even if you do not play a 15kHz sound but only its harmonics, you will hear only one sound: the 'missing' 15kHz. It's called the missing fundamental effect. There are also youtube demos if you still have doubts.

The missing fundamental effect only works if you can hear the harmonics. 30kHz is beyond the bandwidth of human hearing and has no way of implying to the brain that it should fabricate an alteration to the fundamental.

 

[Julf]

Again yes. Or more precisely, it is not a clear NO: may or may not be audible depending on the test signal, your ears, your equipment etc...

What you hear is the 15kHz at the same dB level. It's 'coloration' (btw, called timbre in musical therms) is not 75dB below, it's at the same level.
Think about it as a very "fade" coloration. A light-waves analogy might be helpful to wrap your head around it. E.g. when combining a Yellow wave with a Infrared wave you will see a red-tainted yellow (even though the infrared wave itself is 100% invisible.)

Another flawed comparison between eyes and ears - they are very different.
Do you have any objective, verified evidence for your claims?

 

[Gorgonzola]

The first harmonic of 15 kHz is at 30 kHz. Can you hear that?

To be clear, 30 kHz would be called the 2nd harmonic. (Personally I can't hear 15 kHz much less 30 kHz.)

 

[Julf]

To be clear, 30 kHz would be called the 2nd harmonic. (Personally I can't hear 15 kHz much less 30 kHz.)

Indeed. My mistake. I was thinking of it from a music point of view, where the 2nd harmonic is called the 1st overtone.

 

[lashto]

I am more than familiar with the missing fundamental effect. It only works if you can hear the harmonics. If you can't hear the 30 kHz, you won't hear a 15 kHz missing fundamental either.

Not sure if that is true. Think about the light analogy. Or about the 19kHz+20kHz IMD test. Most people can't hear any of those two sounds but they will hear their 1kHz IMD product.

Do you have a paper that actually tested your "you'll not hear it" assumption?

I would love to see verified, objective evidence you hear any harmonic distortion from a 15 kHz tone.

would like that too.
The only sure thing is: the 15kHz sound will be 'colored' by its HDs. And that is what will reach your ears: a colored 15kHz sound. Whether you'll be able to hear that coloration or not, noone can say (at least not for sure and not for all cases of -75dB HD)

 

[pma]

The only, and rather theoretical possibility are audible intermodulations in tweeter and in human ear. I am not sure if there is any serious research on this, but I believe the result would be rather negative.

BTW, 30kHz wave alone would have hard times to enter in human auditory system.

 

[lashto]

To be clear, 30 kHz would be called the 2nd harmonic. (Personally I can't hear 15 kHz much less 30 kHz.)

If you can't hear 15kHz you may be 'safe'. Or at least much better.
However, things that you can't hear may still produce an effect in your brain/body. E.g. a 5 Hz might kill you. A constatnt & loud 15 kHz will probably produce a sort of headache/annoyance even if you don't hear it.

And guess you can still hear 10kHz, so you still get a "meh" amp. Sorry

 

[Julf]

Not sure if that is true. Think about the light analogy.

Don't think about the light analogy - it doesn't work. As I wrote, eyes are very different from ears.

Or about the 19kHz+20kHz IMD test. Most people can't hear any of those two sounds but they will hear their 1kHz IMD product.

Sure. Because the 19 kHz + 20 Khz IMD test generates intermodulation products at frequencies such as 1 kHz. That has nothing to do with harmonic distortion.

The only sure thing is: the 15kHz sound will be 'colored' by its HDs.

It is only "sure" to you. If it is inaudible, it is not coloration.

Whether you'll be able to hear that coloration or not, noone can say (at least not for sure and not for all cases of -75dB HD)

We can say for sure. You don't hear a 30 kHz tone, and you won't hear any "coloration" of 15 kHz caused by harmonic distortion.

 

[Julf]

If you can't hear 15kHz you may be 'safe'. Or at least much better.
However, things that you can't hear may still produce an effect in your brain/body. E.g. a 5 Hz might kill you. A constatnt & loud 15 kHz will probably produce a sort of headache/annoyance even if you don't hear it.

"Probably"? So now you are just speculating?

And guess you can still hear 10kHz, so you still get a "meh" amp. Sorry

What was the THD at 5 kHz again? You won't actually hear THD lower than 0.5% even on a good day at frequencies your ear is most sensitive to, not to mention 10 kHz...

 

[lashto]

The only, and rather theoretical possibility are audible intermodulations in tweeter and in human ear. I am not sure if there is any serious research on this, but I believe the result would be rather negative.

BTW, 30kHz wave alone would have hard times to enter in human auditory system.

not even sure if there is a 30kHz wave to be played by the tweeter.
My impression is that those waves combine (e.g. in the amp already).
An oscilloscope will not show a 30kHz wave, just a 'crooked' 15kHz wave. I assume that is what enters our ears and the 'coloration' that we hear.

Lots of (my) assumptions and impressions here, would surely like to know more/better. Do you have a paper?

 

[lashto]

Don't think about the light analogy - it doesn't work. As I wrote, eyes are very different from ears.

OTOH, sound and light are both waves. They combine the same way. And acoustic research/phenomena (e.g. timbre, missing fundamental) point out that ears & eyes work similarly. At least in some respects.

Sure. Because the 19 kHz + 20 Khz IMD test generates intermodulation products at frequencies such as 1 kHz. That has nothing to do with harmonic distortion.

Yes IMD & HD are not the same (not 100% diff either). Anyway, it was just an example of inaudible sounds producing audible effects.

It is only "sure" to you. If it is inaudible, it is not coloration.

potato, potato...

The 15kHz wave is crooked/colored. You can see that on an oscilloscope. Objectively-colored if I may say so .
If you prefer to call it 'pure' from the subjective/cantseeit perspective, fine with me..

We can say for sure. You don't hear a 30 kHz tone, and you won't hear any "coloration" of 15 kHz caused by harmonic distortion.

Sorry, won't take anyone's word/assumption here. Neither will take "common sense logic" (and yours is actually pretty good). I'd like to see some hard proof/study. But that's just me...