Dablocks

No worries, willdo. Mine's def the amp section aswell so I'll give Hartke a shout to see if it's something they've come across before. It's worst on low notes and practically non existent on higher notes so a loose part resonating could be a good shout.

Hey man, how did you get on with getting your Hartke repaired? I've just bought one with exactly the same problem and am in Edinburgh too! Cheers