It has the features that i need (2 coax, 2 optical, varying output level) but is is very old (2012).
https://www.whathifi.com/audiolab/m-dac/review
Some reviews are positive but i read one saying it sounded like crap.
The DAC chip is very old so i wonder how it compared to a modern DAC around 400 euros.
I have one for my bed listening setup, and subjectively I've never heard any issues with it. It's also a quality-feeling unit, although the power brick is a little cumbersome. The stereo level meters are cool, too.
One very important thing to note, though: These units suffer from a nasty issue often known as the ESS left channel locking bug, where one channel will suddenly start producing very loud white noise out of nowhere. From what I remember this is an issue in the DAC chip itself, so not something you can work around. If I had to guess I'd say it happens for me maybe once every 200-300 hours of use (with D3E set to Full Suppression and the newest custom firmware), but it's genuinely terrifying when it does happen. Switching inputs on the remote clears it.
I recently fixed one of those, which involved replacing about 100 capacitors and a few relays. It's a common problem, apparently, so if you're planning on getting one, try finding a unit that has been similarly services, or you've got that to look forward to.
Another thing to bear in mind is that the USB implementation is slightly broken and doesn't work right with Linux (glitches every second or so). It does work with Windows 10. No idea about Mac.
What was the issue in the one you fixed? On mine the relays will occasionally stick when starting (going by the sounds coming from inside the unit), causing it to not produce any sound. I've also had it boot up to communication errors once or twice, though a reboot always cleared that. (and my unit's seen some abuse, a spill included)