Those specifications are available from the FAQ here:

What are the basic specifications of the player?

Remember that when you play MP3s, they will not sound the same as a CD player, the frequency response will be a little different because it's going through different output circuitry. Most CD players have their bass boosted a little bit, for example, while the empeg has perfectly flat output with no boosting anywhere.

Regarding the stereo separation specification, please see this.

Finally, keep in mind that how good the music sounds is also a function of your encoder program. I do not know how "good" MMJB is at creating the MP3s.