Apple PC Compatibility Card 12-inch card - Manual (Page 31)

18 Plug one of the CD audio cables that came with your PC Compatibility Card into the
Sound Out connector on the PC Compatibility Card.
Your PC Compatibility Card came with two CD audio cables. They are
different colors to make it easier to distinguish between them, but both work
the same way.
The Sound Out connector is next to the CD In connector, which is at the
upper-left corner of the card.
Sound Out connector on the
PC Compatibility Card Attach the small plug on
the end of one of the
CD audio cables to the
Sound Out connector on
the PC Compatibility
Card. You can use either
CD audio cable.
17 Installing the Card in a Power Macintosh 7200, 7500, or 7600