Hearing other appliances in dedicated line

could be either or both, check your panel connections for tightness

Is your audio system breaker on the opposite leg (phase) as these appliances? That could help.

So big a deal was my discovery years ago that some of the ground wires were not tight inside my 200 amp breaker box Stereophile published my letter to them about it. Taking proper precautions,I hand tightened every wire inside that breaker box. My issue wasn’t clicks but rather, hum. Never heard any anomalies again.  

I have a 4 wire dedicated line one common ground the other a insulated isolated  ground on its on buzz bar and grounding all wires awg 10 Copper

as well as outlets gold over Copper , very quality .

My guess is the noise is not coming through the power line but electromagnetic.  Like I say, that is a guess.  

A dedicated line becomes common with all other circuits at the breaker box so it could be coming through the power line.

If you said you hear only 1 electrical device making noise, I might think it was that component with a problem.  but since it is multiple components, your system is very sensitive to noise.  

Jerry