hypex power ratings

[davidr3032]

You said it, not me. You won't fix them by changing the amp. Just trying to help you out.

I know. And you may be right. The quad is a fine amp

Though I dont know what you're referring to when you say - you said it not me

 

[davidr3032]

@davidr3032 just try an NC502MP based amp from Buckeye or VTV qnd trial for 30 days. That's it.

Thanks. Yes my plan was to try a hypex based amp out. But I was trying to work out which one to go for based on the specs. Something more powerful that what I have but not too far beyond the power rating of 200w recommended by magnepan. I dont wanna have a party and have someone destroy their delicate ribbons by turning the volume up too much. ( im pretending i still have parties)

The power ratings of the amps mentioned are of little use to me in this regard, if they don't correspond to the common way that amps are rated. Which obviously magnepan are referring to. Magnepan aren't talking about 200w peak power 1kHz. Otherwise you'd have to be pretty careful with amplifier matching ( Like they were quad esl 57's or something )

The specs put out there by builders of hypex based amplifiers are confusing. One thing I've learned for sure is that their actual power is less than what figures they stick beside the amps on their websites. How much less, I'm still not sure

That hasn't stopped me wanting to try one though. Just wish I knew the power rating before buying. Its already been pointed out (in the 1st reply) that although the nc400 is rated as 200w its actually less and about the same power as the quad 909. If I didn't do some research and ask folks on here, I wouldn't have known that. Now at least I know that I should be looking for one of the more powerful amps in the hypex range

 

[Matias]

Yes, well, as you can see from all discussions above, power ratings are a complex thing. Many variables like time, frequency, AC input, peak or RMS...

 

[davidr3032]

Yes, well, as you can see from all discussions above, power ratings are a complex thing. Many variables like time, frequency, AC input, peak or RMS...

Yep they sure are. I'm beginning to wonder if it would be easier for me to just to ditch the science and start asking people which hypex amp has the most emotional impact

 

[pjug]

ATI seems to be specifying their nCore amplifiers in the manner that you would like:
https://www.ati-amp.com/images/spec2.jpg

 

[davidr3032]

ATI seems to be specifying their nCore amplifiers in the manner that you would like:
https://www.ati-amp.com/images/spec2.jpg

Wow thanks. That may be the answer im looking for!

So their hypex nc500 amp is called the AT52xNC and its rated at 200w

So thats 200w maximum average power ( 20hz-20kHz ) 0.03% thd+N

So hypex nc500 based amps don't really have a power rating of 400w but its actually half that

Have i finally got the answer to my question?
Or is there some other hypex module in there i don't know about?

 

[Matias]

Yep they sure are. I'm beginning to wonder if it would be easier for me to just to ditch the science and start asking people which hypex amp has the most emotional impact

Well, if this helps:
https://www.audiosciencereview.com/...n-nc500-vs-nc500mp-or-nc502.15123/post-494190

 

[hyfynut]

Hypex gives substantially more performance information than most other manufacturers including Quad.

For example as far as I can tell from the manual the Quad 909 has the following power ratings.

140W into 8 ohm (0.05% THD)
250W into 4 ohm (0.05% THD)
100W into 8 ohm (0.01% THD, 20Hz-20 kHz)

OK, how does the THD change with power level? Is it higher at lower power levels? How does it change with frequency? We do not know because they give us limited information.

Compare this to Hypex which gives you plots of THD+N vs power level for 3 frequencies (100Hz, 1 kHz, 6 kHz).

All power levels discussed so far are AVERAGE power which is calculated using RMS voltage, RMS power is an often misused term and has no meaning. I will agree that the Hypex data sheet tables are not the greatest in terms of how they summarize performance but it is all there for you to see in the plots. Also because Hypex sells modules (not completed amps) you have the additional variables of how will the module be heatsinked and what power supply will be used (not an issue with the Hypex MP amps). However, given all this Hypex still gives you tons more information to evaluate performance.

Looking at the NC400 datasheet at I would put the NC400 power ratings as follows.

300 W into 4 ohm (0.05% THD+N)
150 W into 8 ohm (0.05% THD+N) - datasheet does not show power in to 8 ohm but halving power in to 4 ohm should be close

For the NC1200.

500 W into 4 ohm (0.05% THD+N)
290 W into 8 ohm (0.05% THD+N)

So the NC1200 would provide double the power compared to what you currently have and NC400 would be about the same.

Michael

Most digital amps I’ve seen don’t double output power into halved impedance. Maybe closer to 190 into 8ohms?

 

[mdsimon2]

Most digital amps I’ve seen don’t double output power into halved impedance. Maybe closer to 190 into 8ohms?

It was definitely a conservative estimate, if the NC400 scaled similiarly to the NC1200 you would expect ~175 watts at 8 ohms.

Either way not a huge step change in power compared to the Quad. That being said I agree with other posters that a more powerful amp is unlikely to solve his issues unless he is maxing out the volume on his existing amp and he wants a few dBs more output.

Michael

 

[March Audio]

These graphs seem to show the power rating for the module driven at individual frequencies, not 20hz - 20kHz Presumably if it puts out say 330w at 1kHz, it will put out less than that when all frequencies are driven?

Sorry but thats not how it works. Amplifiers are not measured/tested with "all frequencies driven". That's not what "20hz to 20 kHz" means. Unless you listen white noise it's also not a scenario that will exist when listening to music.

 

[March Audio]

)

The power ratings of the amps mentioned are of little use to me in this regard, if they don't correspond to the common way that amps are rated.

With respect the power ratings of the amps are perfectly correct and normal. The issue here is that you have a mis understanding of those specs and how to interpret them.

 

[March Audio]

So hypex nc500 based amps don't really have a power rating of 400w but its actually half that

No that's incorrect. It's about 370 watts into 8 ohms at 0.03% thd + n.

See the graph I posted earlier.

 

[March Audio]

Per current standards, amplifier power are tested using a single tone sine wave. This means the peak voltage of the signal is 1.41 times (3 dB) higher than the RMS voltage. This ratio of peak to RMS voltage is the crest factor. Therefore, if your amp can output a maximum voltage swing of +/-50 volts, its "power rating" at 8 ohm would be: (50/1.41)^2 / 8 = 157 W. (The 1.41 number in the calculation is the crest factor.)
[Note that the multi-tone is a steady signal, i.e. crest factor is different and separate from the dynamic range of the signal.]

However, music (and multi-tones) is not a single tone sinewave, and has a much higher crest factor. If we choose a more realistic value of 12 dB (= 4x), the power at which clipping starts will be: (50/4)^2 / 8 = 20 W.

I agree with @March Audio that the FTC test method is nowhere representative of the 99.9% use case. Nobody (sane and with intact hearing) drives their amplifer continuously to their max power and listen to single tone sine waves. Why should amplifiers be designed to this requirement?

This

 

[davidr3032]

No that's incorrect. It's about 370 watts into 8 ohms at 0.03% thd + n.


OK if thats the case then why are ATI wrong in their rating of 200 watts into 8 ohms at 0.03% thd+n?

 

[restorer-john]

@davidr3032

ATI aren't wrong. They are rating their product in accordance with the US rules.

This discussion has been had many times on ASR (and other places). Basically, the Hypex power ratings are not compliant with US FTC amplifier regulations, but, as they are only selling components (modules), not complete amplifiers, they can get away with it. It is up to the assembler/builder/manufacturer of the completed product to advertise their product in accordance with those regulations if sold in the US.

The EU regulations are much looser, and, with Hypex in particular, their specifications are cherry picked to look good. Not uncommon practice, many manufacturers do that. They are still an excellent product for many people, don't get me wrong.

The 20Hz-20kHz FTC rating means the minimum continuous average power at a specified distortion or lower can be achieved at any frequency across the specified bandwidth on a continuous basis. It doesn't mean all frequencies at once.

We all know that typical music has lower power demands at high frequencies, but that is irrelevant. It's just an excuse for covering up the inherent problems and un-levelling the playing field. In the case of the Hypex modules, it is more about the dissipation and destruction of the output filter capacitors at high power/high frequencies. They simply cannot deliver their full rated power at very high frequencies (20kHz) for more than a few seconds.

Once classD amplifiers improve with even faster switching devices, filter related dissipation issues will become less of an issue and we'll begin to see full power, full bandwidth ratings. I look forward to that.

In the meantime, you are doing well to be one of the few who read through the specs and into the nitty gritty. Keep up the independent thinking.

 

[March Audio]

@davidr3032


The 20Hz-20kHz FTC rating means the minimum continuous average power at a specified distortion or lower can be achieved at any frequency across the specified bandwidth on a continuous basis. It doesn't mean all frequencies at once.

We all know that typical music has lower power demands at high frequencies, but that is irrelevant. It's just an excuse for covering up the inherent problems and un-levelling the playing field.

How is it irrelevant if when used to do what it is designed to do, ie play MUSIC, only a tiny fraction of power needed at 1kHz is required at 20kHz?

Its the FTC tests that are irrelevant because they dont actually provide a relevant basis for comparison.

How is it "unlevelling the playing field" when say a 100 watt (at 1kHz) amplifier will never ever be required to output 100 watts at 20kHz? The FTC have a fundamental lack of understanding if the think that it is required and is useful information for a consumer.

 

[davidr3032]

Sorry but thats not how it works. Amplifiers are not measured/tested with "all frequencies driven". That's not what "20hz to 20 kHz" means. Unless you listen white noise it's also not a scenario that will exist when listening to music.

OK so my use of language isn't great there. What I should have said was -

These graphs seem to show the power rating for the module driven at some specific frequencies, but do not include all frequencies from 20hz - 20kHz Presumably if it puts out say 330w at 1kHz, it won't be able to do that through all the frequencies from 20hz - 20kHz?

I was just trying to point out that the graphs you posted dont cover all frequencies. And the power rating for full bandwith would be presumably be less than 330w

I dont mean to suggest that white noise would be a viable way of either testing an amp or something that would be useful in real world conditions.

Though I have to admit i do occasionally listen to the compilation cd "Now that's what I call white noise 20"

 

[March Audio]

OK so my use of language isn't great there. What I should have said was -

These graphs seem to show the power rating for the module driven at some specific frequencies, but do not include all frequencies from 20hz - 20kHz Presumably if it puts out say 330w at 1kHz, it won't be able to do that through all the frequencies from 20hz - 20kHz?

I was just trying to point out that the graphs you posted dont cover all frequencies. And the power rating for full bandwith would be presumably be less than 330w

I dont mean to suggest that white noise would be a viable way of either testing an amp or something that would be useful in real world conditions.

Though I have to admit i do occasionally listen to the compilation cd "Now that's what I call white noise 20"

Yes they can output full power at 20kHz, but as I keep pointing out they will never need to to. No amplifier needs to.

 

[pma]

How is it irrelevant if when used to do what it is designed to do, ie play MUSIC only a tiny fraction of power is required at 20kHz than it is at 1kHz?

There is no universal and defined MUSIC, to be used as a standard. And not only 1kHz is requested, but sine waves from 20Hz to 20kHz. As John has already stated.

For an audio signal, the voltage is in Vrms (root-mean-square), the power is referenced to a frequency of
1,000 Hz, and the load is usually referenced to a resistive load. Thus, the power obtained is the average
power that the amplifier can sustain. The FTC requires further that the amplifier be pre-conditioned at
one-eighth of rated total power output (for a multiple-output system, all channels are on) for one hour
using a sinusoidal wave at a frequency of 1,000 Hz. The power spectrum measurement is then collected
with two channels at maximum rated power over the audio frequency range of 20 to 20,000 Hz, in ambient
still air of not less than 25°C, for the duration of not less than 5 minutes.

Manufacturers want to loosen test conditions for their product to look better.

 

[March Audio]

A quick and rough example just to demonstrate. Should really filter and look at the waveform, but this wil give you an idea.

Here is a track from Empire Brass Quintet, so plenty of high frequency content.

Look at the signal level at 1kHz and 20kHz. At 1khz the signal level is around -40dB. At 20 kHz it is another 40dB lower at around -80dB.

Lets put that into power terms.

So if we set the amp output to 100 watts at 1kHz into 4 ohms the output voltage would be about 20 volts. At 20kHz the voltage is 40dB lower. That works out at only 0.2 volts! Into 4 ohms that equates to 0.01 watts!

Do you see that its therefore meaningless to worry about delivering max power at 20kHz?