We have had a spate of 'tron owners calling us with problems relating to noise, buzzes, clicks, pops and radio interference that they couldn't get rid of. There is normally one common solution and all you 'tron owners should take note:
ALL MELLOTRONS SHOULD BE GROUNDED. NEVER USE A 'TRON THAT ISN'T!
Seriously, if you have a 2 pin plug going into a wall socket, cut the bastard off and make sure you fit a 3 pin plug with a proper earth/ground back to the powerpack. If you don't, not only are you in potential danger but none of the screening on the instrument will be effective.
If your house has a poor earth, take a wire from the mellotron mainframe and strap it to a metal pipe that goes into the floor.
And relax...................
M