I don't know shit about audio equipment, and it's not exactly 100% on topic but i need some help.

this is my parent's setup.
the amp is kinda faulty, in the sense that when you touch the volume knob all kinds of garbage audio comes out.

they are dead set on getting it replaced, even tho we don't even touch the settings and just use it to listen to ripped youtube mp3 anyway.

what are some cheap options i can look into that fit into this?