This is the measurements of the March Audio P502 class D amplifier based on Hypex (?) modules. It was kindly send to me by a member for testing. The P502 costs US $1,075 from the company direct.
This is not a review because the
@March Audio is a long time member of the forum and I like to avoid conflict of interest.
The unit comes in attractive aluminum packaging:
On off control is a touch button which is unusual in power amplifiers.
Here is a shot of the back:
In hard use, the bottom plate gets quite warm. Make sure you have plenty of ventilation from below. A taller set of feet would help with this.
My heavy stress test of frequency versus power caused the unit to shut down momentarily. I did not retry it as I don't want to risk damaging the unit.
Warm Up Test
As is my standard practice now, I warm up and measure distortion and noise until the device stabilizes. For amps, I do this at 5 watts. Here are the results:
View attachment 45908
As you see the channel in red is having a harder time, showing fair bit worse performance than the other. It did improve momentarily after power up but then went back to the same state. I checked all of my cabling and it was all secure. So don't know if this is an assembly issue or sample to sample variation.
Amplifier Audio Measurements
As usual we start with our dashboard:
View attachment 45907
Per warm up test, we see one channel with higher noise floor and differing distortion products. Averaging the two channels still puts the P502 well above average amplifier:
View attachment 45909
Frequency response was essentially flat in audible band with a resistive dummy load or my speaker simulator:
View attachment 45910
View attachment 45911
Crosstalk was good enough and predictable:
View attachment 45912
32-tone test simulating "music" shows that 1 kHz is actually the point of higher distortion. Below and above performance improves:
View attachment 45913
Signal to noise ratio is quite good:
View attachment 45916
Except for the one channel lagging behind. We are talking about 16+ bits at 5 watts reaching up to nearly 20 bits at full power.
Amplifier Power Measurements
Let's start with 4 ohm load:
View attachment 45914
That is a ton of power with very low distortion. Letting the distortion go up to 1% gets us even more:
View attachment 45915
Switching to 8 ohm load we get:
View attachment 45917
Conclusions
Lots and lots of power in above average performance and small package. If you are going to drive a sub with it at full power, you may want to deploy more cooling/ventilation on the bottom.
------------
As always, questions, comments, recommendations, etc. are welcome.
I don't want to come across as too obvious with respect to asking for money. It just isn't me. But please do me a favor and
donate what you can using
: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/