I was having noise issues with my 70s Clone Theory, hum, buzz etc. depending on the venue. The early versions are hard wired to a 3 pin plug. I know a great amp tech in North Shields, Route Two Amplification, so asked him if he could take a look.
The overall repair wasn't straight forward but it's back up and running and sounding brilliant. The original plug and lead removed and replaced with a 12V DC 'Boss type' power socket, plus a couple of mods to the circuit to help keep the noise away and level out the on off volume.
I'm a very happy boy...