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.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: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.As usual we start with our dashboard: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:Frequency response was essentially flat in audible band with a resistive dummy load or my speaker simulator:Crosstalk was good enough and predictable:32-tone test simulating "music" shows that 1 kHz is actually the point of higher distortion. Below and above performance improves:Signal to noise ratio is quite good: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.Let's start with 4 ohm load:That is a ton of power with very low distortion. Letting the distortion go up to 1% gets us even more:Switching to 8 ohm load we get: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 andwhat you can using