This little schematic shows how I connected 2 cdrom 
drives (1 cdrom and 1 cd-r drive actually) and the Amiga 
soundoutput to one output
The cdrom-audiocables have both been fitted with 
standard 3.5mm stereo jack.
This is done because my mixer is fitted in a box.

Some notes are in Dutch!!

 PERMSSN    UID  GID    PACKED    SIZE  RATIO METHOD CRC     STAMP          NAME
---------- ----------- ------- ------- ------ ---------- ------------ -------------
[generic]               150679  150679 100.0% -lh0- c2eb Jul 23  2000 3-1 CD-Rom Mixer.jpg
[generic]                  204     305  66.9% -lh5- 1c0d Jul 26  2000 3-1 CD-Rom Mixer.txt
---------- ----------- ------- ------- ------ ---------- ------------ -------------
 Total         2 files  150883  150984  99.9%            Aug 28  2000