@peter_s The LHY linear power supply with batteries has a switch on the front, I run it on a 14/8 cycle, meaning it's in battery mode for 14 hours ( I only listen in the evenings so the batteries are engaged after dinner) in the morning before I leave the house I flip the switch on The front panel to charge and it charges until I get home. The front panel has a light display divided into four parts and it's usually still at 50% when I switch it to charge. It can still be used while charging but the linear power supply is engaged so whatever noise it creates will be included in the power signal. I use a good quality short USB ribbon cord from the LHY power supply to the node nano and the LHY is plugged into my power conditioner. The nice thing about the LHY is that there's no power interruption when you switch from battery to charge and back to battery, so the node nano does not reboot every time you start a new cycle. I have also run the node nano with a regular LHY linear power supply without a battery option it sounds better with the battery option. It works great for me and it's not inexpensive experiment.
Cheers