I agree with most of what Artemis *Seven* wrote in his review. I have some Sennheiser HD 25s which I leave on my desk because they're tough and cheap and I don't have to baby them. They're a little bright but resolve pretty well so I keep them handy for monitoring recordings on some of my TASCAM gear. Other times I run them out of a Chord Mojo I have connected to a Linux box.
Last night I played some high rate PCM sample files and SACD rips over the RME and I couldn't believe what I was hearing. This DAC is beyond superb. It turned the HD 25s into a high end listening experience. The headphones absolutely disappeared and I was there in the concert hall. Just fantastic. I don't remember a wow moment like this. And I could not have expected it from this pair of headphones.
RME has a forum and there is a good chance that bugs in the firmware will be addressed. The device speaks for itself as soon as you listen to it.
The DAC comes with a real dead-tree manual, spiral bound and lay-flat so you can linger over it and you will need to! However the manual comes with a note saying it's somewhat out of date. I think it should have gotten the latest manual.
The RME does not seem to be a good pairing for my Sennheiser HD 600s but I'm not really surprised since the 600s are usually much happier on tubes. This is not a complaint about the RME, just to let anybody know that if Sennheisers are your main phones like they are for me, you might want a separate headamp to drive off the RME. I have several here but have not had the time to experiment.
I have not tried to run the RME into a hifi system but from what I have heard on phones I believe it would be difficult to beat. For now it is used as a DACAMP on my desk. The lights-out mode is neat but that is only an option when the device is on. When it's off there is a bright red ring around the power button. There should be an option to turn that off completely.
There are tons and tons of features and settings and I find navigation a little confusing. Three controls rotate and can also be pushed and their behavior depends somewhat on where you are. UI is hard. This is good but quirky. You won't be bored...
I still can't figure out how to deal with the EQ but to be honest I haven't spent much time with the manual.
The DAC has protective features so it won't burn up a pair of expensive IEMs or blow up your ears. A lot of thought went into the details on this. I'm impressed with that, it is somewhat unique. But I too would have preferred 2 x 1/4 inch headphone jacks rather than one for headphones and one for IEMs.
One ongoing annoyance is that the device is really light and the feet don't grip. It slides all over the place when pushing buttons, plugging and unplugging headphones etc. If it weren't so hugely musical and so hugely customizable it would be easy to think it was junk. I'd still like some real traction on a table top but this piece of gear is definitely staying around and no plans to ever sell it.
