Allnic H-3000 hum when mute button engaged.

I found , more than once . that a different cable often takes 2 weeks or more
to "settle" in a system .  Even an old one you move around for that matter .

schubert"a different cable often takes 2 weeks or more
to "settle" in a system"

It sounds like something is very wrong with your Music Reproduction System such as badly contaminated plugs jacks or connectors or defective wire that should be discarded or some other odd failure point that can be readily corrected by a experienced and competent technician of which you should avail yourself so as to remedy this misfunction.

If you're on the West Coast, I agree with others that Albert Porter will probably treat you well. He may even be able to recommend a repair person in your area of California.  Dave Beetles is also a first rate person. And yes, it would seem fair to have the other guy pay for any repairs. By the same token, I doubt he was aware of the problem, which likely is the result of shipping and "handling".

I am lucky in that Bill Thalmann's shop is only about 30 minutes from my house.

Thanks everybody,
I got the message from the seller. There is the toggled switches on the back of the unit fir changing between Balance and Rca outputs selection. He suggested I check it on first (which i forgot to do). I will do it this evening and report back.
Calvin

Good catch. I didn’t even think of that. Hope that solves the problem.
Then you can get down to the serious business of rolling rectifiers. :)