Clean ground

@Pauly- you sound like you know your way around a soldering iron, so I don’t want to patronize you in this response, but are you talking about a clean dedicated ground that is connected to the main ground or an isolated ground? I have the former- a run of 4 gauge directly up to my room at the time I had the wiring done. It is tied to the house ufer, as I think is required by Code. @Jea48 is your man on Code-related issues assuming those apply where you are.
Let’s see if the link will work to an image. If not I will delete. The photo is there and shows the buss bar and the black 4 gauge feeding it. Sorry it is out of focus in that part of the photo but it was the only close up I had that included it that I could find quickly online.

@whart

Close. I’m thinking a clean dedicated ground line but NOT connected to the house mains.

I’m thinking a dedicated ground line to use for my audio. Perhaps a couple of ground spike in the back and a cable running from there into my lounge? I’d like to hear from folks who had done something similar or close to similar.

Is your bus at the copper colored bar towards the left rear? That would be great. I need one that’s not connected to the house main ground, but a second dedicated for audio ground.

Thanks.

@Pauly- so is it safe to say that nothing in the audio system plugs into a wall receptacle for the household electrical system, but instead, the entire system is battery driven? Apart from the system that charges it (which is connected to your electrical system, I presume). I wonder how this would be treated under the applicable electrical code since if my assumptions above are correct, none of the system components are "plugged in" to the household system.
@Jea48 might have some insight, which is the only reason I’m tagging him-- I’m sure he has other things that occupy him too. Interesting question. I have a battery powered line stage with tubes that is a marvelous sounding beast.

You asked: "Is your bus at the copper colored bar towards the left rear? That would be great. I need one that’s not connected to the house main ground, but a second dedicated for audio ground. "
Yes, it is blurry, the focus was on the phono stage sitting in front, but that's a standard copper buss bar that I adapted with some generic fittings to mount on the wall. And the 4 gauge cable (you can see where it attaches to the bar) runs back through the house down to where the electrical sub-system with big Iso-transformer are stationed. I had commercial electricians do the work. It was worth it. 

@whart

Correct.Nothing touches a wall socket with the exception of the three prong plug that provides access to ground.

I charge when I’m not listening.

In the rare event that I want to take input from, or output to, a device that is plugged in on a wall socket, I use an audio engine Bluetooth connection. There is never a physical connection between components on battery and components on mains.

If you have a better pic of that there busbar I’d like to see it. Even focused images seem blurry to me so your pic is challenging.
Thanks

Pauly- here's an example, I think you can get these cheaper and they are sold on Amazon as well.
I will also try to take a photo of my set up that better shows the bar and post it later. In the meantime, here's the commercial site.