drum machine mods weird earth problem help

[selfpreservation]

hi i have just finished the 606 but am having weird earthing issues
its fine in the house ect
in the studio even when running on batteries if i set it down on one side of the studio there is a rediculous humm coming off it , if i pick it up an put my thumbs on the metal plate the hum dissapears
if i move it to the other side of the studio the hum dissapears and  can set it down
the pots all come through the plate and they have conductivity with it , also one of the pots bodies goes back to ground on the 606 so essentially all the pots bodies are going to ground
i have tried all manner of balanced /unbalanced cables / plugs / desk channels ect
im not sure if i need to isolate all the pots and switches from the plate  

any ideas whats going on here ?

[Gordonjcp]

Is the plate connected to a grounding point in the drum machine?

[selfpreservation]

i have connected the plate to the back of one of the snare mod pot bodies  which also has a wire that goes bcak to ground

[electoyd]

looks good though, hope you get it sorted, when it hums do all the mods work ok and does touching any part of it make the hum worse or better?  i'm presuming its loud.
ian

[selfpreservation]

the bd tune mod the cables running to it seem very earthy it almost sounds like touching the end of a jack cable when its plugged into an amp , im gonna replace it with a shielded cable and re route it inside the machine today see if that helps the bd tune mod itself is just replaing a resistor with a pot and resistor in series so i reckon it may be touching something on the pcb

[electoyd]

a bit of hot glue can be quite good for getting cables to sit in the right place, good luck now hope this works out sure you'll be itching to play with it.
ian

[selfpreservation]

this was caused by my wrong toms mod i think it was because i replaced a resistor which was in parallel with 2 caps  anyway sorted know