The CD player should not go through PC-6 at all. That board is for low-level inputs, and is equalized for phono.
The most simple solution is to reinstall the tape monitor switch, which can be used as a two position selector switch.
Since the selector switch and tape monitor switch are removed, then the output from PC-6 must be going directly to the blend switch, balance control, or volume control, depending on what's still there.
Reinstall the tape monitor switch as shown in the original assembly manual, with tape amp, aka tape in (not tape head!) wired to one side of the switch, and output from PC-6 (eyelets 1 and 7) wired to the other side. The center lugs of the switch are wired to the blend switch, balance, or volume.
Hope this helps.
Last edited by Flyquail56 on Sun Jan 06, 2013 1:06 pm; edited 1 time in total (Reason for editing : added eyelet numbers)