Noise from main outs (solved - not an MPC problem)

Hi. I bought my 4k (4000 plus) about a year ago but only really getting into it now.

I've noticed that there is low level noise coming from the main outs, it sounds like glitchy grumbly computer noise, possibly crosstalk from the HD. Its fairly low level but it is very noticeable when the machine isn't playing. Not constant hiss, more like 'computer talk' noise, grrr grrr blip blip grrrrrr etc. Like static.

However listening via the headphone socket is totally quiet.

Anyone had this?

I have not encountered this with my mpc 4000 or my Z4.
Have you looked inside to see if there are any loose wires that look out of place?
Cheers
Ian

i've solved it - it's an electrical issue in my studio, nothing to do with the MPC.

sorry! but thanks for the reply