Yes you are. MP3s are a slightly lossy compression format, good enough for presenting musical concepts and general musical files, but not if you are particular about the details of the sound, its depth and so on. The MDR on the other hand does not compress sound and plays back in higher fidelity than MP3. It is comparable to the quality of a native AIFF file, It hink. I do not know what the sample rate (samples per second) or sample depth (bits per sample) is exactly, but this is my impression from listening to them.

A