By the same logic all devices "contaminate" each other in the service box and then the grid. Best have each source in different states than the amp.
Single plug dedicated circuit?
I guess if you truly want to do a dedicated circuit wouldn't you have to be allowed to only plug-in one device. If you plug two items into the outlet isn't one item going to contaminate the other item with noise from the first item?
So a multi branch circuit would be sharing 4 items.
I guess it gets down to sharing and Best to share with one but tolerable and acceptable to share with 4 components plugged into the quad outlet?
So how many people are only using one component per circuit breaker which is the truly finest way to receive a pure signal, at least if you ignore what occurred before the current reached the circuit breaker.