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Great thread, I'm going through buckets of popcorn.Seems to me that the FTC test tells you nothing useful. Whats the use of knowing that an amp can run for 5 minutes at full power on a sine wave when there is no music that will ever get it near that dissipation? It's not helping the consumer.

I don't see a reason to doubt the power numbers. I have done a lot of research on these competing amps and the March power data is consistent with what's in the datasheet. They just don't have an undervoltage Hypex PSU. This is measured data not module spec. Still waiting to see more...

@pma I did ask march audio about the thd+ V snr on their forum. Alan confirmed that at the 5 watts point, their is no significant difference between the two. https://forum.marchaudio.com/index.php?threads/new-p482-stereo-power-amplifier.78/post-424 They also have released 3 1et6525 based amps...

Probably mainly a problem for class AB amps. The reactive low impedance loads will make them get very hot. This isn't any issue for class d but some designs may suffer bus pumping and shut down.

A Bryston is an expensive well engineered amp. Whats the price tag on these? Is it aimed more at the lower end market? Where cheaper less capable amps prevail?

I traced the impedance plot in virtuixcad and imported into REW. Someone might want to check the data, but I think its good. The EPDR dips to 1 ohm and it spends a wide area below 2 ohms. A class AB amp will probably get very hot.

We have magnitude and phase so should be able to calculate it from Nuyes data. I will try to.

I agree with you if we are talking about higher power output, but March was talking about a specific power point of 5 watts. Your graph shows there is less than 0.5dB difference at this point with that particular amp. I don't know, but I suspect the Purifi modules have negligeable increase in...

A typical class A or AB amp will struggle more with low impedance reactive loads than a class d. They will get very hot. No such thing as watts rms. What difference does the current being quoted as peak make? 40 amps peak with a test sine wave is 28 amps rms. Quoting a peak current limit...

This, I agree with you. 2.2 ohms is not great design. XO needs reworking. Ironically the phase angle will be far more an issue for class A and AB than class d.

March basically measured the amp noise with inputs shorted then added the THD component from the measurement.

The Purifi 9040 is a bridged design. Suffers none of these issues.

I have been doing a lot of research into class d recently as I'm deciding what to buy. What you say is not true. Examples below.

I asked March about this on their forum. Reply was basically its the low variable voltage out of the hypex psu that means the module output will be limited. Around 210 watts at 63 volts.

I know. Take a read of March explanation of how the corrected figure is derived. Signal generator noise limits the accuracy.

@boXem I'm sorry I have come across that way. Apologies. I'm just trying to compare the data that's out there. I do take your point about the different generators. So do I understand your position correctly in that the power outputs from the modules vary significantly? It would still be...

That's fair enough, but he explains the reasons why. What is your noise level with the inputs shorted? Alan syated the measurements were taken with 21.0dB gain. Your measurements were taken at 20.4dB gain. So as we discussed in the other thread this is too low to reach full power output of the...

I have been waiting to see this data. 115dB SINAD! I think k Boxem posted a quick measurement of their version in another thread, but it wasn't close to this.

So the psu is too low a voltage to reach the modules rated spec and Buckeyes stated specs are wrong. It is indeed a thread about your amps. Just trying to get to the bottom of contradictory information.