rca splitter

Hi there, I will soon be getting a turntable and was wondering if it possible to connect my external preamp for the turn table as well as my pc to my receiver using splitter cables so I can use both sources at the same time. Any help would be great. Thanks in advance

Hello! Sorry for the dumb question :facepalm: but I'm wondering if this is a feasible thing to do? I only have one decent stereo speaker system which is currently connected to my computer with the diagram below: I would like to connect a record player to the speakers, but I'm not really sure...