My USB flash drive Sony 8G has done the system disk after (formatted FAT32) in the big stereo (dancing square dance kind of) the sound is small almost inaudible also had deep formatting
U disk is just to store data, whether you use the U disk to do not do the system, will not cause the sound is small. u disk as long as the data can be written and read out there is no problem, do not toss it. The reasons for the small sound are: 1: the tunes deposited into the USB flash disk itself is low level (can be adjusted by software); 2: the plug-in audio problems (including the part of the plug-in card). If your stereo plug other USB flash drive, play music loud enough, you can be sure is deposited into the U disk of the original sound of the tune is small, can be replaced to try.