BUCKEYEAMPS Hypex NCx500 Amplifier 2channel Review

[MaxwellsEq]

It could be interesting to know how long it was demanded to this amp to run over 100W continuously, If it had been running above 325W more than 10 sec, if proper cooling time was done in between tests. Again not that he should have, but good info to assess

I agree. That is a fair question. Based on the PSU data, high power tests above 300W should be under 10s with appropriate cooling. On the other hand, protection should have prevented failure.

 

[Toni Mas]

I agree. That is a fair question. Based on the PSU data, high power tests above 300W should be under 10s with appropriate cooling. On the other hand, protection should have prevented failure.

Regarding additional protections, considering the power available and home use, i dont think necessary.
Btw, maybe a red clipping led when reaching the last 3db might help to avoid abuse, like done with most pa amps...

 

[MaxwellsEq]

Regarding additional protections, considering the power available and home use, i dont think necessary.

This is not "additional" it is necessary. The amplifier modules should not be allowed to overload the PSU. The protection should kick in after 9s and reset after a sufficient time.

 

[Toni Mas]

This is a different question that arises from the choice made by the assembler to use an underated PSU. This is the only reason for an additional protection that should have been provided by the assembler, Hypex has no responsability on this.
I maintain a clipping led is useful to warn power hungry users.

 

[Sokel]

Regarding additional protections, considering the power available and home use, i dont think necessary.
Btw, maybe a red clipping led when reaching the last 3db might help to avoid abuse, like done with most pa amps...

I haven't dig enough on specs but previous modules had clipping indicators readily available.

 

[Toni Mas]

I haven't dig enough on specs but previous modules had clipping indicators readily available.

I have a pair of Hypex DS4.0 subwoofer plate amps with ucd400 module inside, and they actually have a clipping led. So that continuous use of these rated 400w is clearly warned against.

 

[Sokel]

Lets not forget that we're talking about a 10 years old design (talking about the PSU,can't see any major revision in the spreadsheet) that was maybe designed for entirely different needs.
The little I have dig in the protection scheme it seems to heavily rely on current limiting amongst the other usual protections.

I'm not trying to justify anything,of course protections should kick in.
But it's maybe time for a new design meeting the specs of the new models.

 

[RickS]

Mostly good and interesting points on the question of amp specs and reliability, but am skeptical of the whole review as there is a lack of solid information on several fronts…

1. Allegedly a power supply failed but lack details on how and why.
2. Without a replacement power supply on hand, cannot be sure there are not other amp issues as yet.
3. While the OP seems well-intentioned, not sure whether some test error occurred either.
4. There is no established baseline in the OPs testing. Whether some loopback and/or known baseline test amp, cannot be sure of the validity of any of the results. This review has plenty of data but, in my opinion, lacks sufficient context to draw solid conclusions.

Would hope good test practices are being applied but would be good to see them demonstrated too. Whether Amir, or I or any other tester, the test rig needs to be in a known trusted state prior (and after testing) or the results will be suspect. Do not care how good or expensive the test rig is, if the tester does not demonstrate discipline around solid test practices, speculating on the results (and drawing conclusions based on them) is counterproductive. More testing is needed. Until that happens, suggest that owners should continue to enjoy their amp.

 

[sarumbear]

The OP blew up his friend‘s Class AB AVR too, so would hope he is introspective enough to consider that his testing or test rig may need some modification.

Have you considered that he is doing a more rigorous test then you or @amirm?

 

[Sokel]

Mostly good and interesting points on the question of amp specs and reliability, but am skeptical of the whole review as there is a lack of solid information on several fronts…

1. Allegedly a power supply failed but lack details on how and why.
2. Without a replacement power supply on hand, cannot be sure there are not other amp issues as yet.
3. While the OP seems well-intentioned, not sure whether some test error occurred either.
4. There is no established baseline in the OPs testing. Whether some loopback and/or known baseline test amp, cannot be sure of the validity of any of the results. This review has plenty of data but, in my opinion, lacks sufficient context to draw solid conclusions.

Would hope good test practices are being applied but would be good to see them demonstrated too. Whether Amir, or I or any other tester, the test rig needs to be in a known trusted state prior (and after testing) or the results will be suspect. Do not care how good or expensive the test rig is, if the tester does not demonstrate discipline around solid test practices, speculating on the results (and drawing conclusions based on them) is counterproductive. More testing is needed. Until that happens, suggest that owners should continue to enjoy their amp.

To be honest here @thin bLue has left little to speculate after his Marchaudio P422 re-review.
I have never seen such detailed presentation of gear and test practice.

The fact that admits his faults (unprecedented as far as I read reviews for years) and asks (happily! ) for guidance adds a level of transparency that we're not used to.
We have few to trust,we must encourage them.

Furthermore,it's not reviewer's responsibility to protect and amp against it's protections.
We have seen Amir's reviews that amps regularly shut down as they should.

 

[sarumbear]

The data sheets of the Hypex module or SMPS are not vague, in fact they are quite comprehensive.

I found the spec sheet for the amplifier.

https://www.hypex.nl/media/74/2a/5b/1678365773/NCx500%20-%20Datasheet%20R0.pdf

The continuous power rating is only limited with thermally. In other words there is no difference between peak (whatever that means) and continuous. Cool the amplifier and you can use it up to 700W.

I then looked the spec sheet for the PSU but on the series document the output specs for SMPS1200700 specs was missing. However, there is a general notice that says:

The SMPS1200 is designed for music reproduction and is therefore not able to deliver its maximum output power long-term. The RMS value of any common music signal generally doesn’t exceed 1/8th of the maximum peak power. The SMPS1200 is therefore perfectly capable of driving the connected amplifier in clipping continuously with a music signal without the need of forced cooling.

Thanks to @Sokel I found what I missed on the document. There is still direct data missing for the SMPS's own performance but we still see that the SMPS Amplifier pair should be able to deliver 700W for a considerable length of time (10s) and should not fail.

https://www.hypex.nl/media/8c/22/86/1646037796/SMPS1200Axx0_10xx.pdf

A very odd thing is all power specs are given as total amplifier output power of the connected amplifier. There is no power spec of the SMPS at all!

Then again on the website they have the following.

ELECTRICAL FEATURES:​

• High Line Input Voltage: 200-240Vac +10%
• Low Line Input Voltage: 100-120Vac +10%
• Output Voltage: 2x85Vdc
• Max. Output power: 1500W
• Max. Output power: 1200W @20Hz
• Switching Frequency: 100kHz

How does 20Hz enters in the power output of a SMPS???

That is not what I would say comprehensive specifications.

Furthermore, the manufacturer explains a protection circuit that in theory should not allow what happened on the test.

The SMPS1200 also features an advanced over current protection which in case of temporary overload limits the output current. Only when the overload condition remains for a longer time the supply will enter hiccup mode until the overload condition disappears.

 

[sarumbear]

I agree. That is a fair question. Based on the PSU data, high power tests above 300W should be under 10s with appropriate cooling. On the other hand, protection should have prevented failure.

Where do you see that data?

 

[Sokel]

Where do you see that data?

I have the link here (under the screenshot) :

BUCKEYEAMPS Hypex NCx500 Amplifier 2channel Review

And mind you, i have never broken anything in my life! Not if you count yourself mucking up this thread with your pedantic and useless replies.

www.audiosciencereview.com

 

[Toni Mas]

I couldn't find any data sheet on the Hypex website. May I kindly ask you to point them to me? The only spec I saw is this which was posted by @GXAlan who has not linked the document he screenshot.

It is very strange to see continuous power of a 700W rated amplifier to be as low as 100W. However, there is a notice for that value, which is not shown. Also, we do not mean how they define peak either.

From what I see so far the manufacturer specs are not comprehensive. Hence, the need to see the full specs.

This document is part of the manufacturer's doc. So their warnings are perfectly clear.

Btw, and regarding their smps psu they also carefully warn that the voltaje available at the rails is not intended for a continuous Signal( sine, squared, triangle, etc...) but for a musical program only.

Hence the question what defines a musical program? Answer: its dynamic range. What is a conservative enough dynamic range? Answer from AES appliyng to loudspeakers: 6dB or a x4 ratio from rms to peak power. Imho, 10db is more than enough, or a X10 ratio from continuous to peak power, 70 to 700w for example. In this case, 700w for peak and 100w for continuous is very good indeed. At least for home use.

 

[sarumbear]

I have the link here (under the screenshot) :

BUCKEYEAMPS Hypex NCx500 Amplifier 2channel Review

And mind you, i have never broken anything in my life! Not if you count yourself mucking up this thread with your pedantic and useless replies.

www.audiosciencereview.com

I am sorry to have missed it. I found the links myself immediately after I posted and have now revised my post. I appreciate if you re-read it.

 

[sarumbear]

I have revised my previous post considerably. I apologise to members who had already replied while I was revising it.

 

[Apollon Audio]

However, they are one of the few manufacturers that provide actual measurement results, and they readily agreed to show 150 point sweep. I think that should be highly appreciated. I'd love to see a 20 Hz sweep as well.
I'm trying to find out more how they handle such power with the same PSU.


Replacement alone does not prove that it has been completely repaired, so a true replacement naturally involves testing. It's also one of the things I must offer to amp owner.

I'm sorry I forgot to add the 20Hz to the sweep. Here is the 20Hz sweep.

 

[Apollon Audio]

Even looking back again, it's still interesting! Could you lend one to Korea for measurement?

I think this is not needed as Amir already has one unit there waiting to be reviewed.

 

[PeteL]

I found the spec sheet for the amplifier.

View attachment 303910
View attachment 303909

https://www.hypex.nl/media/74/2a/5b/1678365773/NCx500%20-%20Datasheet%20R0.pdf

The continuous power rating is only limited with thermally. In other words there is no difference between peak (whatever that means) and continuous. Cool the amplifier and you can use it up to 700W.

I then looked the spec sheet for the PSU but on the series document the output specs for SMPS1200700 specs was missing. However, there is a general notice that says:


Thanks to @Sokel I found what I missed on the document. There is still direct data missing for the SMPS's own performance but we still see that the SMPS Amplifier pair should be able to deliver 700W for a considerable length of time (10s) and should not fail.

View attachment 303911

https://www.hypex.nl/media/8c/22/86/1646037796/SMPS1200Axx0_10xx.pdf

A very odd thing is all power specs are given as total amplifier output power of the connected amplifier. There is no power spec of the SMPS at all!

Then again on the website they have the following.

ELECTRICAL FEATURES:​

• High Line Input Voltage: 200-240Vac +10%
• Low Line Input Voltage: 100-120Vac +10%
• Output Voltage: 2x85Vdc
• Max. Output power: 1500W
• Max. Output power: 1200W @20Hz
• Switching Frequency: 100kHz

How does 20Hz enters in the power output of a SMPS???

That is not what I would say comprehensive specifications.

Furthermore, the manufacturer explains a protection circuit that in theory should not allow what happened on the test.

I never doubted that maximum continuous power on the module is limited by heat, that is just stating the obvious but good thing they mention it. On the previous versions specified when using the reviewed power supply and in a finish design with no additional heat management.

I don't know what the Max Output for a 20 Hz signal mean too, but at least the specs are detailed. By comprehensive, I meant complete. They Are clear that it's with an amplifier as a load. I agree that it could require explanations, but I am quite certain that if you are a manufacturer with an account at Hypex, selling amps with their PSU, you would get answer on why. What do you mean by no specs for the PSU at all? It is measured when powering an amplifier when relevant, and otherwise specified. The cooling setup is explained.

Edit: for there are much more comprehensive data for the SMPS in the download section. You just quoted the quick main features page.

 

[RickS]

To be honest here @thin bLue has left little to speculate after his Marchaudio P422 re-review.
I have never seen such detailed presentation of gear and test practice.

Thanks, cannot say I gave that review much scrutiny so point taken.

The fact that admits his faults (unprecedented as far as I read reviews for years) and asks (happily! ) for guidance adds a level of transparency that we're not used to.
We have few to trust,we must encourage them.

This is good, but can like the interaction and still see room for improvement. Ask no less of Amir or myself. Will readily admit having shared some results only to find I was mistaken. If you post test results that question a vendor’s reputation, you should be prepared show what steps you took to ensure your results were valid. Could the power supply been failing from the start and might be why the amp was not making rated output in earlier testing?

Furthermore,it's not reviewer's responsibility to protect and amp against it's protections.
We have seen Amir's reviews that amps regularly shut down as they should.

Again I agree, but unless I missed something, we simply have what happened and not much else to go on. Is the OPs incoming power good? How does his testing differ from Amir’s and is there a need to modify? Did the power supply simply suffer an early failure? Just too many unanswered questions from my perspective to draw much from this review.