(cont. from a previous related thread here) :wink: RCA type wires are poorly shielded, if at all. In fact this brings up another related issue. Some muscians use wires that are not even shielded, which is an invitation for AC hum... especialy when such unshileded wires are layed close to any regular AC line or power strip. I feel coaxal (t.v. cable) cables are a great example of a very well shielded cable. (but DONT use cable tv wire for audio purposes :lol: ) Also keep in mind that a customized guitar might be lacking any shielding, which might only induce audioble hum at over driven/distorted (hard rock guitar) levels. For heavy metal over driven distortion things sometimes have to be shielded with very thick metal.... thus those heavy stomp boxes such as the old MXR (distortion) often have real weight added for the only reason of shielding..... I feel the best shield is copper, but good ole alunuimum foil can go a long ways when one is in a money pinch.