It was also noted on another forum, that the colour of the lead can make a difference to the capacitance of the lead (different chemical dyes in the plastic having an affect). A studio owner made up two guitar leads, all Neutrik jacks, identical cable manufacture and type apart from the colour - one red and one white. He has someone come in to re-record a guitar part from a previous session in November and wanted to get the same sound. Try as they might, they couldn't get the sound the same. Then someone suggested swapping the lead, so they changed the red one for the white one, and instantly the sound was there again!