One thing that I like about Audiogon is that one can have good discussions with others here without having to worry about trolls and negative discord. I disagree with the idea that the power feed must come from the same leg on the power panel and we had discussions about that here and yes, we do agree to disagree.
Having the power feed from the same leg will not be a problem at all, except as I mentioned the load at the panel may not be balanced. Which can cause electrical issues.
I have seen nor heard any evidence that having power from both legs causes any problems at all and in my case it definitely does not.
But, remember, that either way, one must not share ground or neutrals with anything. The hot, neutral and ground leads must go all the way back to the panel.
Other things that can and often do cause ground loops and buzzing is poor interconnect cables where the return is tied to the shield. Or, if the electrical component has a poorly designed grounding scheme.
There are many reasons why people experience ground loops/buzzing. The very last reason that I would suspect would be using separate power feeds from the panel.
The ground and neutral are all tied together in the panel. So as long as these run independently back to the panel, you are good. I suspect bad component ground design scheme or bad/poor interconnects.
In my case, this is a non-issue and I have my power feeds balanced on both sides of the panel. If someone has this same set up and has ground loop or noise problems, I would love to hear about it.
Audiogon is a great place for these types of discussions.
enjoy