well one things for sure its not the USB cable. does the fostex use digital volume control or analogue? are you having to use them right at the beginning if the dial? the fostex isnt really specified for really low impedance, this may be why, perhaps the pot used, due to size and budget doesnt have the greatest tracking at the beginning of the range.
A much better alternative than broken ears right?
you could test this by reripping a couple of tracks with the volume turned a fair way down, to enable you to turn the volume control up further, perhaps this will get you past the area where it doesnt track well and the balance will be restored. thats not a long term solution of course, as you will be lowering the dynamic range of your music and raising the noise floor, but it may help you to get to the bottom of your issues
Edited by qusp - 6/25/12 at 3:22pm