I have been using a number of different external DC lithium-ion batteries, and have run into a problem. I have two Power Stick lithium-ion supplies (small, variable 3.5 to 7V output); one of these causes a very low level noise on the meters of my MiniR82, the other is clean. I have been running a Korg MR-1000 with the Battery Geek lithium-ion fixed output 11V cell, I am getting some low frequency junk in the signal, which may be DSD related or (I worry) maybe from the power supply. What is the best way to test for this, and is there any easy fix to screen it out of the audio chain?
Jeff