Being from an era when there were no CD players and the myriad of other equipment we now attach to receivers it only has two 5-pin DIN socket inputs, one for phono and the other for a tape deck / aux. For years he swapped a DIN to RCA cable between his CD player and tape deck to cope with the one DIN line-level input.
At about the same time his CRT TV and turntable broke, the new TV adding an extra input (awful internal speakers) and both replacements with RCA connections. He shopped around for a solution but no store had anything helpful.
So I made a box with:
3 RCA inputs switched to a single DIN output
A direct RCA to DIN connection for the turntable.
The plastic enclosure is coated on the inside with RF/EMI shielding.
I used a nice selection switch which has a grub screw to hold it in place.
The underside has stick-on rubber feet.