I’ve decided to reply to this thread trying to help future potential of UR28Ms.
After a long time not using my UR28m which, mind you, has served me well when I was beginning my journey in audio, I have needed to put it to use again, for editing and light mixing duties at home.
I am completely shocked with the low quality of the headphone outputs in this interface.
Since I had stopped using it, I have worked with my RME Fireface UFX and Steinberg UR816c and coming back to it was absolutely impossible. I very much prefer using my Elektron Analog Rytm as a soundcard than the UR28M, unfortunately. It is night and day between them.
With both a DT990 pro (250ohms) and a HD28 pro (64ohms) the UR is a mushy shrilly mess, very distorted and very fatiguing, with indiscernible lows and terrible imaging. I dunno if the unit’s outs are faulty (since the preamps don`t work anymore), but it doesn’t seem so - it’s not THAT bad that I think its defective… I guess it really just sucks… =(
Its still very dear to me, because I have learned a lot through it, but am very disappointed.
I haven’t tested its main outs to see if they are as bad, and I don’t think I will so I don’t spoil even more of my fond memories.
EDIT: to be clear, I didn’t set up and went about comparing the Elektron to the UR28m to decide. I started using the UR, thought “damn this is bad” and then went to the Elektron.