BUCKEYEAMPS Hypex NCx500 Amplifier 2channel Review

[thin bLue]

Until a new progress comes out, if you want to check my list of major failures, please check the following link!

Thread 'Yamaha RX-A8A Review' https://audiosciencereview.com/forum/index.php?threads/yamaha-rx-a8a-review.47002/


BTW, When I first check Amp's AC, DC with DMM, I forgot to test them with load and filters(for AC), so 90% of work turned Data to Trash right after I realised about that fact. That's why the only 1 Ch @ Med gain is showing on this review.

 

[thin bLue]

Do you think the same fault can happen again?

I think still some possibilities when I do exactly same process, but there are still some possibilities PSU do stand. So Important thing is doing new test with careful settings!

 

[TNT]

@ 4 Ohms
1. Med gain 20K -> 20 Each
2. Low gain 20K -> 20 Each
3. High gain 20k -> 20 Each -> after this, in a Min.
So After make the graphs we see, then rest in clicking.

BTW, Owner reported PSU have arrived, so soon we can see new results!

Thanks! So at very high frequencies. Thats reassuring as that kind of levels at that frequency will never arise while playing anything at least reassembling music

//

 

[Toni Mas]

3. High gain 20k -> 20 Each -> after this, in a Min.

Do you mean it happened one minute after this last measurement, at idle (without signal at input) ?

 

[tmtomh]

Because it means that the Thermal Dissipation Power is taken into consideration during the sizing of fans and heatsink. Many CPU's and GPU's run at 100 % TDP when gaming for example. It is just expected that they can dissipate the heat from the power supply and chip. Why would you expect otherwise? It is not an edge case at all.
Years ago when I worked with AutoDesk Inventor and wasn't docked in at the office, my laptop GPU would run 100 % for up to 6 hours / day on complex 3D models of buildings, plants etc.

The analogy IR to engines wasn't one I did originally. I just wanted to state that any engine that can't run at full power in longer sessions is a shit engine. Same is valid for engines used as power generators on ships or as emergency backup gensets. Or electric motors used on pumps. Air compressors etc. All designed for 100 % load or more continously / indefinately.

If it breaks down at full rated load within its operating range, no matter the type of machine, it is a poorly designed machine and it should be derated.

Yes - but most of those CPUs and GPUs don't run at 100% TDP by magically being thermally designed so that they just touch 100% and don't go over. They run at 100% through thermal throttling, which by definition means the thermal design is not sufficient for cooling them over long periods of time when max power demands are being put on them - the chips clock themselves down and reduce their performance in order to stay within their TDP.

The analogy with amps would be that they reduce their own power when they exceed a certain thermal/power-demand threshold. With some active speakers we see a version of this when they have built-in limiting, meaning they reduce the output below and/or above a certain frequency when the SPL gets too high. With passive speakers we get compression, which is just a less-intentionally planned acoustic/mechanical version of the same thing. With other active speakers we simply see that the clipping light comes on, or they temporarily shut themselves down. And with most amps we see protection circuits that work in a variety of ways.

The idea that traditional Class A/B amps consistently dissipated more heat than they generated, even at 100% power output over long periods of time, is to my knowledge an untested claim. Most or all of us have experienced Class A/B amps that get increasingly hot with use, and that's usually at normal, loud home-listening levels that are not anywhere remotely near constant running at 100% power rating. To be clear, I am sure there are some, maybe many, amps that can run indefinitely at full power - pro amps used in concert venues, for example. But even there, such pro amps are typically run hard for a couple of hours at a time, not constantly or indefinitely.

 

[GXAlan]

To be clear, I am sure there are some, maybe many, amps that can run indefinitely at full power - pro amps used in concert venues, for example. But even there, such pro amps are typically run hard for a couple of hours at a time, not constantly or indefinitely.

What about any pure Class A hifi amp? Shouldn’t those generate the maximum amount of heat for any load?

 

[Deleted member 48726]

Yes - but most of those CPUs and GPUs don't run at 100% TDP by magically being thermally designed so that they just touch 100% and don't go over. They run at 100% through thermal throttling, which by definition means the thermal design is not sufficient for cooling them over long periods of time when max power demands are being put on them - the chips clock themselves down and reduce their performance in order to stay within their TDP.

The analogy with amps would be that they reduce their own power when they exceed a certain thermal/power-demand threshold. With some active speakers we see a version of this when they have built-in limiting, meaning they reduce the output below and/or above a certain frequency when the SPL gets too high. With passive speakers we get compression, which is just a less-intentionally planned acoustic/mechanical version of the same thing. With other active speakers we simply see that the clipping light comes on, or they temporarily shut themselves down. And with most amps we see protection circuits that work in a variety of ways.

The idea that traditional Class A/B amps consistently dissipated more heat than they generated, even at 100% power output over long periods of time, is to my knowledge an untested claim. Most or all of us have experienced Class A/B amps that get increasingly hot with use, and that's usually at normal, loud home-listening levels that are not anywhere remotely near constant running at 100% power rating. To be clear, I am sure there are some, maybe many, amps that can run indefinitely at full power - pro amps used in concert venues, for example. But even there, such pro amps are typically run hard for a couple of hours at a time, not constantly or indefinitely.

IR to chips GPU's / CPU's they are of course not run over 100 %. This is a definition question. Just as amplifier power. A GPU is limited to perform 100 %. This 100 % load is defined as various performance figures which the GPU/graphics card is guaranteed to do at a 100 % load. According to the design criterias different parts of the graphic card can be the limiting factor e.g. power limit by cooling design, GPU speed, VRAM speed, GPU voltage limit. When all of these criterias are considered for the specific card the specifications are then given and are below the threshold of the above mentioned limiting factors. Then the definition of 100 % is defined and the BIOS limiters are set so, that it cannot go further than the defined 100 % by limiting the factors above that cross the threshold.

This is actually a very good comparison to amplifiers as different components of an amplifier will be the limiting factor of the performance; power supply, cooling solution etc.

My point is that the 100 % load definition should at all times be below the threshold of damage to any component. Otherwise that value (for amps that is power) which is specified as 100 % should be lowered until no risk of damage is present. This is good design.

 

[xaxxon]

For accuracy I would say peak 1200w, continuous 325w.

The brief posts of mine regarding 1200w being possible for longer with proper active cooling were a discussion exercise and not meant to try to change the continuous rating.

I would throw something in there about "standard musical playback level" or something... something to make it clear that the max number is the one comparable to (many?) other manufacturers.

 

[BrokenEnglishGuy]

so this all 22 pages drama was for a bad PSU?

 

[CapMan]

View attachment 304277

Few weeks ago.. xD

Replicating crazy dynamics of Real World always be challenging. I'm really sure.

How loud is that clarinet from a seat in the auditorium - I guess not 110dB - the real world doesn’t involve sitting 1m from the clarinetist I guess , unless you play second clarinet )

 

[Hipocrates]

so this all 22 pages drama was for a bad PSU?

The times we're living

 

[Toni Mas]

Correct me anybody if i am wrong but i am under the impression that the designers of these combos smps psu + Class d modules tend to assume considerable risks at running at dangerously high voltage supply in order to allow delivering impressing peaks of power, way beyond the continuous power their amps can safely supply. Then sophisticated protections are also implemented, but maybe not always bullet/idiot proof enough...

 

[Buckeye Amps]

I would throw something in there about "standard musical playback level" or something... something to make it clear that the max number is the one comparable to (many?) other manufacturers.

Agree. It’s more so where to put the information. Either a link to an FAQ entry so I have more room for a deep dive explanation (and even links to other sources), or a quick note somewhere on each product page.

 

[tmtomh]

What about any pure Class A hifi amp? Shouldn’t those generate the maximum amount of heat for any load?

Yes they would, I would think. Are you aware of tests of Class A amps where they are run at 100% of their maximum rated output for a long period of time? It would be interesting to see the results if such tests have been conducted.

 

[peng]

What about any pure Class A hifi amp? Shouldn’t those generate the maximum amount of heat for any load?

Of course, a 300/600 WPC class A amp may weight over 150 lbs and need a 230V 20 circuit, not practical for most people.

 

[Salt]

Seriously,
I never had need of more than 50 or 60 watts to damage my ears while listening ....
Hundreds of watts are needed for those who drive speakers with extended EQ far beneath the specifications of the speaker, or speakers that are very low on impedance and thus badly constructed ... or both.

 

[tmtomh]

Seriously,
I never had need of more than 50 or 60 watts to damage my ears while listening ....
Hundreds of watts are needed for those who drive speakers with extended EQ far beneath the specifications of the speaker, or speakers that are very low on impedance and thus badly constructed ... or both.

Agree. Of course one might need a good deal more for transient peaks - but again, that's not continuous power.

 

[Sokel]

Of course, a 300/600 WPC class A amp may weight over 150 lbs and need a 230V 20 circuit, not practical for most people.

There's an AB "heavy" one at 300/600 watt with 3KW PSU.
I wonder what JA means by that "continuous"...

Esoteric Grandioso M1X monoblock power amplifier Measurements

Sidebar 3: Measurements

www.stereophile.com

 

[MaxwellsEq]

so this all 22 pages drama was for a bad PSU?

See post #49 by @Apollon Audio

 

[BrokenEnglishGuy]

Seriously,
I never had need of more than 50 or 60 watts to damage my ears while listening ....
Hundreds of watts are needed for those who drive speakers with extended EQ far beneath the specifications of the speaker, or speakers that are very low on impedance and thus badly constructed ... or both.

I always wonder what happen when in for example APOEQ you put -12dB in the preamp.
The speaker become harder to drive? For example i have my R7s with a different EQ for LEFT and RIGHT, the thing is it's -12dB per channel..? So what ? xD now is -12dB less efficient my speaker?