Interconnect sceptic sees the light

Had an interesting experience last night. I've been having some trouble with my 92R (converted Nait 3) which needs balancing to about the 11 o'clock position for the correct balance. So I thought I'd check to see if the interconnect was causing the problem. I dug out an old Chord Cobra RCA to Din cable I had from years back when I had a Rotel CD player. I connected it to the Aux RCA input on the pre amp and sat back to see if the balance isssue remained. It didn't fix that but what was immediately apparent was the difference in sound quality between the Cobra and the Naim interconnect. The Cobra was so much more engaging and the vocals sounded as if they were several feet higher and more forward. I must have swapped back and forward 10 times between cables. This was a tangible and qualitative improvement. I checked the Naim cable was properly aligned (heat shrink ring at source end.) The Naim cable sounded reserved and totally uninvolving in comparison. Detail was there but the central image was underwhelming. And then I realised that the Cobra was the "wrong way round" as well. Spooky. And I've always thought that exotic interconnects were the Emperor's new clothes...

I'd love to know what others might think about this. Is there a difference in gain between the aux and CD inputs? Has anyone any thoughts on the balance issue? Can I put a test meter on the output of the NAP180 with a test tone running without harming it?

TIA for any input.