Hypex Nilai500DIY Amplifier Review

[lashto]

Can you point me to that bet? Happy to take it.

be my guest. We just need someone to do the test

Spoiler: offtopic for any bet-takers

You might wanna think a few more minutes about the missingF test at 15kHz:

• an amp is needed that can reproduce 50+kHz. I may have some but no way to reliably check/prove that.
• @HarmonicTHD's idea about using Distort is hardly practicable. Distort signals (and any digitally generated signal above 20 kHz) will be cut quite fast by the DAC filter. A NOS/filterless DAC might help. I don't have any.
• Using an analog signal generator is probably the 'surest' way. I don't have any.
• An oscilloscope would be very nice as a control device. Don't have any either.
• Let's say that I am the 'lucky' one and I can hear a by-product of a 30/45/60kHz combo signal. How exactly do I prove that I heard it? How do I prove it is exactly the 15 kHz pitch? And assuming that I solve both questions, how do I prove it's the missing 15 kHz fundamental and not some IMD product?

Doesn't sound like an easy-peasy test to me. Or something I can do.
But maybe someone designs a test that can be done by the AverageAsrJoe and €100 goes to ASR. Good luck!

 

[Sokel]

1. @HarmonicTHD's idea about using Distort is hardly practicable. Distort signals (and any digitally generated signal above 20 kHz) will be cut quite fast by the DAC filter. A NOS/filterless DAC might help. I don't have any.

Nothing stops you testing with higher sample rate where the filter won't cut at 22050.
See,it's all there:

 

[lashto]

Nothing stops you testing with higher sample rate where the filter won't cut at 22050.
See,it's all there:

View attachment 263561

good point. I'd still prefer an analog generator but a digital signal at 192kHz should be fine too.
Any suggestions for the other issues?

... looks like this missingF thing needs its own thread...

 

[Sokel]

good point, a 192kHz signal should be fine.
Any suggestions for the other issues?

... looks like this missingF thing needs its own thread...

Any AB class amp goes up to 50K,lots of class D ones,I even have and old relic that goes to 500K.
Seems it's all you need.

 

[Julf]

AFAICS, someone needs to do a test. Generate those 30/45/xx kHz harmonics, find a tweeter/supertweeter combo that can play them and test if anything is audible. You'll probably have a AES-worthy paper if you do it properly. And I'll donate €50 to ASR if you are right. And if you devise an experiment that I (and anyone else) can do without needing a special supertweeter, I'll donate €100.
And of course, if it turns out that I was right, you'll take care of those donations

You seemed to demand a positive acknowledgement of accepting your bet, so yes, that is a bet I happily take. I will donate $50 or $100 if it turns out you were right in claiming a missing fundamental can be heard even if all the harmonic distortion is beyond human hearing.

Note that that doesn't apply to intermodulation products - we know those are audible.

 

[JayGilb]

Can we keep this on topic ?
This pissing contest can go to another thread if needed.

 

[pma]

... looks like this missingF thing needs its own thread...

So do it! It seems it is you who needs to understand, not the "issue" itself. These review threads always convert to a kind of pell-mell and it is frustrating.

 

[lashto]

Less than $8. Piezo Horn Speaker Tweeter

Would be useful to spend more than 10 secs on your suggestions. Very nice price. But it can only do 3-27kHz, i.e. useless for this purpose.

So do it! It seems it is you who needs to understand, not the "issue" itself. These review threads always convert to a kind of pell-mell and it is frustrating.

Did it. The thread at least.
Still can't see how I can do a reliable test with my resources. Highly welcome to advise in the extra thread!

 

[lashto]

So do it! It seems it is you who needs to understand, not the "issue" itself. These review threads always convert to a kind of pell-mell and it is frustrating.

and going back on-topic, you also have all the tools to asnwer @boXem's question.
What is that -75dB THD at 15kHz made of? Is it an N increase or is it a THD increase? Exactly what HDs would be nice to see too ...

 

[Sokel]

and going back on-topic, you also have all the tools to asnwer @boXem's question.
What is that -75dB THD at 15kHz made of? Is it an N increase or is it a THD increase? Exactly what HDs would be nice to see too ...

Most definitely distortion component,it's measured with 45Khz bandwidth,there's no way it's noise went up there.
You can see it's FR is almost ruler to 50Khz,so...

 

[Matias]

Most definitely distortion component,it's measured with 45Khz bandwidth,there's no way it's noise went up there.
You can see it's FR is almost ruler to 50Khz,so...

Exactly. The datasheet shows frequency x THD+N for 3 power levels. The bottom one, 100W, shows above 10 kHz that it drops completely. If there was noisefloor increasing or other non-harmonic distortions with higher power, they would show above 10 kHz. But since it drops, that means
A. the measurement was bandwidth limited to 20 kHz; and
B. Right before 10 kHz it was rising (noise shaping) and drops, so that the higher harmonics are filtered out.
That is was our ears are hearing, not that 45 kHz bandwidth graph...

 

[Deleted member 29551]

@Alpha Audio is on here. Just tagging them. They should do some DeltaWave comparisons from the recordings.

For YouTube audio comparisons, everyone is generally right here. It’s a really poor way to compare speakers but when you CAN hear differences it means that the magnitude of difference is large.

What has been suggested and we can more easily tell with the original audio is that the volume is not well matched. Still, this suggests that if you did simply swap your amplifiers that you might find the amps with slightly higher gain to sound slightly better.

Not sure why I should invest valuable time and resources in doing research for people that are just making fun of other people that are enjoying a hobby. It's really mind blowing to me. Dutch people are known for their 'directness'. And sometimes a little over the edge, but at least we stay polite and don't make fun of other people.

To me, that means that you should also stay polite online. Because - you know - on the other side, there are people too. Actual living beings. People you don't really know. and don't know their background from. I assume that people have good intentions. I don't feel that vibe here.

Comments like: "Did these @Alpha Audio guys know something more that we mortals don't? It was a good laugh that they seemed to be serious about it." are not really inviting. They actually hurt... We are human beings as well you know.

And there are a LOT like these, because we actually investigate and try to measure stuff that others don't even dare to look at. Why are we being burned down for that? For fun? Because you think you know better? Because we actually try to proof there is a difference between cables, switches and other gear? What is wrong with trying? What's wroing with publishing stuff for other enthusiasts?

I'm not actually asking for answers, because I don't expect a serious answer or any form of empathy on this forum. Enjoy your day / evening / life. See ya.

 

[Julf]

Because we actually try to proof there is a difference between cables, switches and other gear? What is wrong with trying?

A bit of advice from someone who also isn't a native English speaker, and is familiar with Dutch directness (that works a bit more one way only than Nordic directness): You comments would probably be better received if you said you are trying to find out if there is a difference between cables, switches and other gear, rather than stating that you are trying to prove it. The first formulation indicates an open and inquisitive mind, the other indicates you already know the conclusion, you are just trying to find things that justify it.

 

[Killingbeans]

Comments like: "Did these @Alpha Audio guys know something more that we mortals don't? It was a good laugh that they seemed to be serious about it." are not really inviting. They actually hurt... We are human beings as well you know.

My Nordic directness sees that as nothing but an invite to constructive debate

 

[boXem]

You can see it's FR is almost ruler to 50Khz,so...

Hard to follow you here. FR is not related to noise.

Yes, it might be some of the noise below. I can't really say for sure from this graph but I can't see any N that will translate into 75 SINAD. Not until 500kHz. It's one of the reasons why I went with the HD assumption. And still think it's valid.

Anyway, you should be able to use one of your amps for a (more) conclusive measurement

View attachment 263557

FFT gain prevents you to eyeball any conclusion about the noise amplitude from such a graph.

 

[GXAlan]

If you listen at an average level of 110 dB, your 15 kHz content is likely only 70 dB or probably even less. Any harmonics will be at least another 50 dB down from that. No way you’ll hear any of it, even if you had bat ears.

The dynamic range you describe is still 40 dB which isn’t out of the realm of potentially audible in certain cases. High frequency masking is also volume dependent. It is at lower volumes that you are more likely to avoid masking.

http://hyperphysics.phy-astr.gsu.edu/hbase/Sound/mask.html#c2

Not sure why I should invest valuable time and resources in doing research for people that are just making fun of other people that are enjoying a hobby. It's really mind blowing to me. Dutch people are known for their 'directness'. And sometimes a little over the edge, but at least we stay polite and don't make fun of other people.

Hope.

The world is full of silo’d thinking and “us vs. them” mentality. When others become uncivilized you can respond with civility to hope that you can make the world a better place.

We can prove there are measurable differences from digital cables. There are always surprises to be had.

Review and Measurements of Wireworld Starlight 7 USB Cable

This is a review and detailed measurements of Wireworld Starlight 7 flat USB cable. It is on kind loan from a member. The cost is USD $100 including Prime shipping for the 1 meter/40 inch length I am testing. For this review, I compared it to my current favorite, the 6 foot/1.5m version of...

www.audiosciencereview.com

I certainly believe we will be able to prove that amplifiers can sound different. We have software tools that can help tease out measurable differences between two recordings, looking at phase, impulse, etc. @maty thinks the piano sounds very different. Here is where we might be able to use DeltaWave to see what is a measured difference between the recordings of the piano pieces which aren’t seen when comparing two different tracks.

 

[Julf]

We can prove there are measurable differences from digital cables. There are always surprises to be had.

Surprises to whom? Anyone who understands basic physics knows there are measurable differences between cables. What we are interested in is if those differences cause any *audible* difference.

I certainly believe we will be able to prove that amplifiers can sound different.

How about also proving that the earth is round?
Of course amplifiers *can* sound different.

@maty thinks the piano sounds very different.

Well, yes, he thinks a lot of things. Referring to him just diminished your credibility by yet another notch.

 

[voodooless]

The dynamic range you describe is still 40 dB which isn’t out of the realm of potentially audible in certain cases. High frequency masking is also volume dependent. It is at lower volumes that you are more likely to avoid masking.

The lower volume the less distortion there is. At below 5W high frequency distortion < 10 kHz is comparable to 1 kHz. So also at a lower volume, the masking effect is still significant, especially because distortion scales more with volume at high frequency.

 

[GXAlan]

The lower volume the less distortion there is. At below 5W high frequency distortion < 10 kHz is comparable to 1 kHz. So also at a lower volume, the masking effect is still significant, especially because distortion scales more with volume at high frequency.

Agreed. I was reading your comment out of context and just thinking about musical content being masked.

Surprises to whom? Anyone who understands basic physics knows there are measurable differences between cables. What we are interested in is if those differences cause any *audible* difference.

“Now I didn't expect this!” -amirm, in reference to the differences he measured

Amir didn’t measure differences in the cable itself. He saw differences after the audio device by changing a *digital * cable. It’s not audible but more about encountering something for the first time. Sort of like fusion ignition. We care about actually delivering power but it’s exciting to achieve ignition. That review is still a “first” to see a digital cable having an effect after an audio device.

Of course amplifiers *can* sound different.

But does an Eigentakt sound different from a Nilai in alpha audio’s test?

Even if the difference is volume, what was the dB difference in that test that was experienced as differences in the piano track?

Well, yes, he thinks a lot of things. Referring to him just diminished your credibility by yet another notch.

Yes, because referring to someone’s opinion means I agree with them on everything they write…

 

[lashto]

Most definitely distortion component,it's measured with 45Khz bandwidth,there's no way it's noise went up there.
You can see it's FR is almost ruler to 50Khz,so...

That's pretty much what I assumed and wrote in my initial post about the troublesome -75THD: it's all/mostly extra HD.
Looks like I might have been just right about that. Incredible

Not sure why ~100 extra posts happened in the meantime .. a case of the good old shi.t happens, I guess ..