Hi,
Thanks for the info. So what you're saying is that I could use an MF10 as a notch filter to filter out the 4KHz, but that there's probably no point as I will still get the 8kHz and 12kHz tone coming through? (you have to talk in plain english with electronics and me I'm afraid lol).
Regarding you're other suggestions, I have tried the invertor away from the guitar completely, but the pickups still pickup the tone from the AC in the string itself, which obviously I can't shield as then you wouldn't be able to see it! And I think it's the guitar pickups themselves that are picking up the tone, so shielding the wires to the pickups wouldn't make any difference.
Unfortunately it's starting to sound as if I can't use the EL string.
Thanks anyway, if you have any other thoughts then let me know.
regards,
Rich