ASR M500 MKII Review (DAC & HP Amp)
Release Date:2022-01-05 Views:392

This is a review and detailed measurements of the SMSL M500 MKII DAC and Headphone Amplifier. It was sent to me by the company and costs US $440.

I really like the look of the new SMSL UI. It is more modern and nicer to look at. I am surprised though that they still show the input data type in large letters (PCM) rather than volume level which is far more important. Most people play nothing but PCM anyway. Would be nice to also see the selected DAC filter on the home screen.

Another nit is that the 4-way arrow in the remote control does nothing unless you are in the Menu. Would have wanted a set of those to control which input is playing.

Otherwise, the unit is nice and easy to navigate and use. Here is the back panel showing the usual connections:

The unit is based on ESS ES9038Pro DAC chip.

SMSL M500 MKII Measurements
Let's adjust the output to get 4 volts nominal output and run our dashboard:

This is excellent performance and easily lands the M500 MKII in our top 20 DACs ever tested:

Output capability is higher though and with it, better SINAD can be had, matching company advertising:

RCA output as usual drops performance a bit but still superb:

Dynamic range is exceptional showing great attention to keep noise at absolute minimum:

Note again that the output is at 4 volts. It does get better if you allow full output.

Multitone test shows the exceptionally low distortion again:

Linearity is textbook perfect as one would expect in this class:

USB Jitter is as good as it gets:

And rather surprisingly, so is Coax and Toslink which tends to not be as good in other products:

IMD distortion is kept at minimum with almost no sign of classic ESS IMD Hump

You have the usual choice of filters:

Fast linear is the default from factory.

Finally, here is our THD+N vs frequency with that filter:

Other filters produce different results due to different levels of attenuation as you see in the previous measurement (but still very good).

SMSL M500 MKII Headphone Output Measurements
You can select to turn headphone on and off through remote and it has its own volume control which is nice. Let's measure its power output relative to distortion and noise:

These are very respectable power levels for an included headphone amplifier with superbly low noise and distortion.

Dropping the level way down to 50 mv to see noise for very sensitive IEMs and we get very good performance but shy of state of the art:

Sorry but have not had time to listen to it. I expect it to sound superb though.


The tests I run probe audio devices from different vectors to attempt to find weaknesses in them. Often one or two tests show something. Not the case here. It is clear SMSL engineers have meticulously tested and optimized this design as to leave nothing for me to complain about. You have a superbly performing DAC with more than good enough headphone amplifier in one box. And price is reasonable compared to anything higher performance.

It is my pleasure to recommend SMSL M500 MKII.

P.S. I did test for one channel being active which was an issue with the original M500 and the bug is not here so all is good.

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