So I had a free minute to look up a gut shot of that amp.
Something like this looks similar, but you would have to take any measurements to see if the pin spacing, screw holes, etc, match up (although the
ebay listing is crap and doesn't have any dimensions, lol). You can ignore the red / white colors as they won’t effect it and it will be much harder to find one with the black color. It’s the same basic connector, but that doesn’t mean it will fit.
You also need to take the amp board entire out of the heatsink to solder it in / replace it properly, which is a can of worms in its self if you aren’t careful. Those transistor clips are not always easy to remove and reinstall, and must make sure not to damage anything including PCB pads / traces, transistor insulators, might need new heatsink compound, not easy without experience.
This is free help on a forum, so if this isn't the right connector don't blame me!!!

But yeah, you're basically trying to source something like this that will fit.
Audio Video AV coaxial outlet socket connector. - 2 RCA Jack. - Type: Female. We will leave it for everyone that leaves it for us.
Pic from listing:
Gutshot found at Skars website of an rp1200.1 which may or may not have revisions from yours and might even be a generic stock photo, so its important to open your amp and match it up before buying any connectors: