The signal to an amp is pretty strong. i would not worry about shielding. The main place for it IMO is a Phono pre pre. Where you really want the ultimate clean power, and keeping the A/C wire coming in clean matters. For the rest, it depends on everything else. Do you use conditioners, do you have a tangled mess of cables.(so you would want shielded A/C to protect the signal wires!) or do you carfully route your cables. Do you keep your digital cables away from the non digital? do you use cable elevators?
So all that comes into play.
But, if I had to make a general rule, I would say No you do not need shielded A/C cable for an amp at all.
So all that comes into play.
But, if I had to make a general rule, I would say No you do not need shielded A/C cable for an amp at all.