It's possible that you've got some RF in your listening room, and it is being picked up by any of the cables you've tried for connecting the two units. To support this hypothesis, you could try moving the two JC units as close to each other as possible and using very short cable. Or you could try a cable that is very well shielded. (I like Goertz cables, but if memory serves they are not so well shielded.) Along the lines of what Sfall wrote, it is also possible that either the output of the driving unit or the input of the driven unit is not internally configured in true balanced mode, because I would have thought you would hear at least an improvement when connecting with balanced cables. On the other hand, sometimes RF defies logic, owing to its very high frequencies.