I don't know if all amplifiers produce some hiss or noise, but certainly all systems I have heard do. My system produces a miniscule hiss- I have to remove the speaker grill and place my ear inside the exterior plane of the midrange driver to hear it. However, I never listen to music from that position!
This does not mean my system is better or worse than yours. Some are just quieter than others.
If noise is audible from your listening position, you should isolate the culpable component/cable/ or receptacle and repair.
Sean has written exhaustively on the method on this site.