Serious distortion from Rega RP1

Hi all,

My Rega RP1 has all of a sudden developed some major distortion. It comes and goes quite suddenly. Presumably, this could be anything from the cartridge to the phono stage, but I thought I'd ask to see if you all think one component is more likely than another to be the culprit. I'm using the included ortofon cartridge, the built-in phono cables, and a Red Wine Audio Ginevra phono stage. Unfortunately I don't have other equipment to swap in in order to isolate the problem area, so I'd appreciate any thoughts. Thank you!