Are there any shielded 2 core figure of 8 cables, out of interest?
Yes, I use Mark Grant figure of eight cables where I can, one on my UB820. There are some other cheaper variants available.
At the risk of drifting off topic briefly, I use shielded mains cables and ferrite chokes based on my experience. Some years ago, when I was living in a flat, my hi-fi system was plagued with mains hum. I started with ferrite chokes, which helped a little. Screened mains cables, Tacima, as I recall, helped further, but what finally fixed it was an Isotek mains conditioner.
Since then I’ve stuck with what I know, which of course where I live now might be overkill. Ferrite chokes are cheap to try, and if you’re handy, making your own screened mains cables is straight forward enough. For example, when wiring up a filtered mains block recently I used Supra screened cable. My main system is connected to an Olsen Sounds Fantastic 8-way power strip.
I don’t subscribe to the Russ Andrews type of nonsense, for example putting your cables on wooden pucks, but I do believe, based on my experiences, that some gentle attention to mains cabling is important. Many if us understand the problems that HDMI cables can cause if they’re too close to TV aerial cables, for example.
In the days of analogue, signal cables definitely could make a difference to the sound, input and speaker alike. In the digital age, no. As I said before, the data either gets there or it doesn’t. Decent shielding is important though.
As for the post that lead to this diversion, start with a bog standard figure of eight cable. If it works, job done. No point spending any more.