I have new amp with a whisper of noise on the headphone socket when it's used near computers/disk drives. I had been wondering if it was picking background noise up through an unconnected input and remembered one electrical engineer advising shorting plugs in unused phono sockets to avoid such problems. I've just found a bunch of these at the back of my hi-fi drawer.
Can I call on the collective AOS wisdom - What do shorting plugs do? Are there any hard and fast rules? Does it depend on the quality of otherwise of the circuit design? Is it a good idea to short unused digital outputs? What happens if I selected a shorted input?
DGP