And just when you thought that shielded coax was the panacea to interference - Shield Induced Current Noise (SICN) from the professional audio company RANE:
http://www.rane.com/pdf/ranenotes/SC...uced_Noise.pdf
These are hard bitten guys - they don't believe in cables sounding different per se - they actually measure things. Their "Rane Notes" are well worth a peruse
http://www.rane.com/library.html
Craig