Create a switched connection for a car AV receiver being used as a home audio system

I was recently gifted a Sony XAV-AX5550D car AV receiver but, alas, I have no car! (I was thinking of getting one, but things as they are…) I thought of selling it but have had VERY low offers. So I decided to profit from its rather good sound quality and turn it into my main home audio system.

It’s up and running perfectly with both the red and yellow leads connected to an AC-to-DC (12V 10A) converter. On the one hand, it just feels wrong to have to cut the power to the converter to turn off the device–though I understand that’s what would basically happen in a car. But I would like to know if there’s a way I can create a switch using the red lead. Especially because every time I turn it off, certain things like the time and date are reset because, as I see in the manual, the memory circuit needs constant power to the yellow lead in order to function.

Any ideas?

P.S. I’m not sure if this is the best SE community for this question but all others somehow seem less adequate. If you think it’s "off-topic", please let me know where might be a better place to ask this. thank you.