Yes a splitter would do the job just fine, or you could get a switcher depending on what you need
So I think it would be worthwhile to pick up a balanced cable for the 4xx for sure, it really appreciates power and balanced cables can be had for around 45 bucks
The 700x and sr80e though, in my opinion are not worth the effort to mod them for balanced. A detachable cable mod might be reasonable if you are into that kinda thing, but personally I don’t think going balanced with them would make that big of a difference
Well ive been using the SU-8 's volume control for the speakers so sould be fine with that. Ive looked at the balanced switches and I guess thats an option although im already pretty limited on desk space to begin with XD. Other option is atm since I don’t have balanced cable for the heaphones yet I could just use RCA to the headphone amp and look at getting switch + cable at a later date.