Ah cool it is on single player Sonic 2 I saw that with. Turns out the hissing didn’t go away just was less noticeable from moving the jack. I googled it and it turns out the person who sold this Genesis 1 sold it with an SA-160A power supply that’s for Mega Drive 1’s and has different specs. IFixit has a thread where people report the wrong power supply will cause the buzzing. So I’ll get a proper power supply soon to see if that resolves it, if not I’ll do the audio mod on my Genesis and I’m pretty sure that will do the trick. Cheers!