Pioneer M-72 Capacitors

You don't need to get Elna brand capacitors, just get good quality audio grade electrolytic. I use Nichicon, but any good audio cap will do. I personally try to get the largest microfarad replacement capacitors for the power supply filters that will fit. I've not had a problem going 2-3 times higher than the original value, but keep the same voltage.

Pioneer is not that good.
Back then, i had a SONY system.

Back then, Sony and Pioneer pretty much sounded the same as did most receivers at that time.