Yes, it is perfectly feasible that you could have a problem with just one channel in the audio output stage.
I personally have a wiring connector going from the amp to my car's right front speaker, that keeps going intermittent and causes crackles. But you say you have ruled this out by plugging the unit into your home stereo and you are sure you hear the same crackle.
In this case, yes, it's very likely to be an internal hardware problem wtih the player. It could be a failing component, or just a conductor on the motherboard that needs to be resoldered. I don't know how to trace this issue. But you could verify it and help narrow it down by checking the following things:
- Check to see if you get the same crackle whether you are using sled outputs or the RCA jacks on the back of the empeg itself. (I know you said you plugged it in at home, but you didn't say whether you had an indoor docking sled or not.)
- Check to see that if you swap the left and right RCA cables at the empeg (when plugged into the jacks on the back of the player itself), that the crackle moves to the other side.
- See if wiggling a connected RCA cable, or wiggling the docking connector on the back of the player, causes the crackle.
- Open the player (using cautions as described
here) and make sure there aren't any loose screws rattling around, make sure the disk drive tray hasn't come undone, look at the audio/power/disk/display wiring and make sure it's not chafed in any spot.
Something else that could cause an occasional crackle would be clipping caused by adjusting the EQ oddly or overdriving the volume. See if you can make the crackle go away if you set the EQ to flat, or turn down the volume.
Another thing that could cause a crackle is disk trouble or corrupted MP3 files. But I doubt you would hear that out of only one speaker.
Beyond that, I think it's probably a trip to Stu or Rob.