older Roland Cube 60 .....low hummmmmm

[Doc Stitches]

Help....

Is a low hum sound normal for the older Roland CUBE 60 amp? It plays and sounds great, but I would like to get rid of the hum.

Thanks
Jim

[oc disorder]

Teach it the words.......................
seriously havn't seen one for a long time check all the jack nuts
are tight seem to remember some of the ones at the back are a main
grounding point.
Also remember having one where the transformer was bolted back
in the wrong orientation.
Its supposed to sit at an angle so the magnetic field doesn't induce
into the circuit.
If its the one I think it is the transformer bolts to the bottom of the cabinet.
This means the mains 110v/240v and the secondary runs down to it.
Suggest removing the speaker and using an extension unbolting the transformer and try different angles to get the lowest hum.
Of course if its stock and never been touched the hum could be elsewhere.
The main filter caps would be a likely culprit too.
According to my schematic they are 2200uF 50volts (2 of them c42,c43).
After that there are 2 more that feed the preamp 470uF 50v c40,c41.
Thats about the best I can do without it in front of me.
Watch out for lethal live terminals in the chassis ..its not worth dying for....!