If your cd player has a digital in (optical), you can just run a toslink cable from the headphone out on your iMac to the cd optical in. This uses the dac in your cd player.
If not, you can get great sound running toslink to any outboard dac, then rca to your pre.
I also like Tan43's suggestion.
If not, you can get great sound running toslink to any outboard dac, then rca to your pre.
I also like Tan43's suggestion.