Step-up Transformer

[Hollowcell]

Thanks for the replies everyone.

Yep, it's a mechanical hum. I think it's just down to the age of the thing itself.
I have read up about magnostriction (think that was what it was called), and how vibration can occur. Just a bit pissed that it has to happen in the studio. What can you do I guess.....

hehe super glue isn't a bad idea - don't think I'll try it just yet though. Maybe I'll wait till I get a fire blanket or similar ready.

For now, I have cased it (not tightly) in some sound proofing and put it as far away as possible in a roomy cupboard.
It's doing the trick, but it won't be the best once summer comes around.