Thank you,
@Lurk650 and
@AKGunkie
I think I was hoping for the obvious, e.g. to be able to use the balanced cable with N40. I have a Sony ZX300 with a balanced (and SE) headphone port. They say it sounds much better out of the balanced port. However I would not take N5005 with me, as I would use them only at home. I might take the balanced cable with the N40 though.
People have pointed me toward balanced cables, but as yet I have not seen a cable that I felt I would buy. The cables that folk suggested were probably very good too, it's just that it's all new to me.
I think that I am really pining to buy the N5005. I am so taken with the N40 for portable and home use. I imagine the N5005 are just a good step better. Possibly very considerably better. There is a £500 price increase, but the N5005 seems to specialise more in accessories, and I wonder if that's where the cost is. The pro-reviews of N5005 are a fraction mixed, so that doesn't help. I know I'd love some TOTL head-phones/ear-phones. It's totally on my list of things to do. I imagine I will finally settle with both good in-ears, and some over ears. With regard to in-ears, it's whether I trust my impressions of the N40 and reviews or not. I'd be busted up, if I felt like the N5005 wasn't a large a step up as I hoped.
It's hard to judge from my perspective of never having heard TOTL headphones though. It's nearly impossible to gauge how much better, that equipment can be. Like I originally had a Mojo, and bought a Hugo 2. The Hugo 2 was better in ways that I hadn't even imagined.
I was hoping to audition the N5005, but as yet have not found a store to do it at. Plus there is no surety that store will have run the headphones in, but they will say they have. Minefield!