Kerouac
Headphoneus Supremus
I remembered about @x RELIC x informing me that a standard 3.5mm interconnect will work (thanks for that!), so I decided to go the silly route and grab my short and inexpensive one that JDS Labs makes for $5. With the two stacked, it's ever so slightly longer than the distance between the two ports, so lengthwise it's perfect.
Wow, I never suspected that you could use a normal interconnect on the coax-out from X5
Have to try that myself soon...
I wonder if the quality of the used interconnect also influences the final sq