Here is another review/test of the Ncore nc502np by hifinews:
https://www.hifinews.com/content/li...-1000-network-dacpre-and-power-amp-lab-report
https://www.hifinews.com/content/li...-1000-network-dacpre-and-power-amp-lab-report
Pink noise is used for this test because it has a power distribution similar to music.
I don't know what you were doing to make the nc400 run too hot but you will see countless reports on the net saying that they run practically cold just bolted to a simple, small thin sheet amp enclosure. That certainly was my experience when I had some.This depends on heatsinks used, for both class AB or D. For example, I can run this amplifier
http://pmacura.cz/pmacfa_en.htm
at any power between 0 - 100% of the specified power continuously, no problem with the 1 hour test at any power.
When I had the Hypex NC400 modules to test here (they were sold by Hypex? few years ago, see below)
View attachment 107130
they were running too hot in that 1/3 power test.
And the class D AIYIMA A07 (that I am testing now) specified at 2x300W/4ohm switches off itself after 1 minute of 1x100W/4ohm/1kHz test.
So it is definitely not true that is a "(total non issue for class d)", as you are saying. No, it is a question of design for any class of amplifiers. Inadequately small heatsinks will make the amp to fail in this test, regardless its class of operation.
As you know, Hypex NC500 OEM datasheet states that continuous power is only 1/5 of the "Peak Output Power" as per their specs. I hope I do not need to paste this datasheet again. It is the old game of "Peak Power", which has been with us for at least 50 years and has not changed and the main reason is marketing.
This is too much generalized, full energy is often up to mids, several kHz, and then it decays, like in this Armstrong & Ellington vinyl. Yes, above 5kHz the energy is generally limited.
View attachment 107193
I
March Audio it seems to me you could end this debate very easily if you just gave more detailed specs on your amps. For example, for your p502 amp your website states -
Power Output
2 Ohms - 450 W rms
4 Ohms - 500 W rms
8 Ohms - 350 W rms
But these numbers mean nothing to me without context. You say its continuous power, but is this full bandwith? 1% thd? Or what?
It seems to me that this is fairly basic info I need to know as a consumer. The fact that you don't agree with the common way amplifiers are measured isn't an excuse to just provide vague power ratings like this
This.This music sample begins at nearly -15db and most under -20db. Nothing is even close to 0db....Pink noise at least starts out at 0db and therefore would be more demanding than this music sample....If you would overlay a pink noise track, it would literally be above this music sample THE ENTIRE TIME. Pink noise bottoms out at -30db....
As pointed out pink noise doesn't behave like you think.This is too much generalized, full energy is often up to mids, several kHz, and then it decays, like in this Armstrong & Ellington vinyl. Yes, above 5kHz the energy is generally limited.
View attachment 107193
There is a bit of a misunderstanding about phase shift.Someone told me hypex module have 20 degree phase shift at 20khz and this results in loss of detail. True?
Why does an amplifier need to have power bandwidth above 35kHz?
That would be a brilliant thing to do, it would save us periodically having to go through all these myths and FUD spreading. Just point to the FAQMy "Class D FAQ" topic is long overdue... I will get around to create it eventually...
No. John is on ignore and wrong for the reasons pointed out over and over again. I can't be bothered to listen to his FUD
He doesn't understand the technical reasons why the things he thinks are important are of no relevance.
It's all pretty basic but he just doesn't get that music is not continuous sine waves.
He doesn't understand that music power content reduces dramatically with increasing frequency.
Until he takes these simple facts on board and acknowledge the flaws of the blunt instrument the FTC test is, its clear that he will continue to make this uninformed noise and threadcrap any subject to do with class d.
It's just best in this case to not indulge and just ignore him.
Just curious, has anyone ever heard any complaint from anyone that Hypex amps don't live up to expectations with respect to their power output? Anyone herd any reports of them shutting down due to temp? I haven't.
You've missed the point. The Hypex doesn't even have a full power bandwidth beyond 5kHz. Read their "disclaimer" (note 7).
I'd be happy with 20kHz full pwer bandwidth with a Class D. It can't achieve a quarter of that.