Just thought I'd wrap up this thread by giving my impressions of the Phiaton ms400 headphones I've been using since Xmas 2012.
Overall, I'm very pleased with these 'cans'. My impression is they're a little bumped up in the bass but still maintain good detail and texture from bottom to top. The all-important midrange I would describe as neutral to the source/recording but, at the same time, very smooth and natural. The treble sounds very good; extended highs with a smooth and natural quality. I've never seen a frequency response curve for these headphones but I suspect it would show a slight bump in the bass region with a slight attenuation in the upper treble region. The only reason I say the upper treble may be toned down a bit is because I've never experienced listening fatigue even after hours of listening. The build quality is impressive with the use of carbon fiber and they're very comfortable with soft leather on the ear cups and headband. I've bought several of the all black versions of these headphones as gifts and everyone has been very pleased with them. Highly recommended.
I'm using a HifimeDiy tiny dac ($35 from Eastern Audio) that attaches through the USB port and bypasses the laptop's internal dac. And I'm using J River's Media Center to manage high resolution lossless music downloads and ripped cds. So far, so good with computer audio.
Thanks,
Tim