i didn't modified the GUS config at all in dosbox.
This is my config edit in the .conf now:
# Lines in this section will be run at startup.
# You can put your MOUNT lines here.
rem MOUNT a A:\ -t floppy
mount c F:\old\PCDOS
mount d K:\dosboxd
mount e N:\ -t cdrom
imgmount f K:\dosboxe\BAT2_CD\cd\bat2.bin -t cdrom
imgmount g E:\Games\PC_on_E\EWJ2_CD.cue -t iso
mixer CDAUDIO d-15 ; gus d-5
The F, G CD-ROMs are permanently, now.
The dosbox-0.74-3 does not load when I start the program a lot of time. I have to close it down and start again.
The SW Dark Forces GUS music gets problem in the into. I tried to change the digital channel to Sound Blaster but it didn't get anything better with the GUS music audio (because it is a different channel but I tried everything).