17' unbalanced cable v balanced with ISOMAX

Thanks for the clarification, DB. What had particularly confused me was the reference to "Jensen ISOMAX transformers at the amps to transition from XLR to RCA," but I see now that you meant physically near the amps, not electrically connected to the amps.

As I said, though, I don't think the results of a long unbalanced connection can be predicted with confidence. Among many other variables and unknowns that are involved, one important one would be the relative sonic quality of the balanced and unbalanced outputs of the Cary. Per my comments in the other thread, though, it seems conceivable to me that the reason for the noise you heard when you tried using XLR-to-RCA adapters at the KUBE inputs may have been that the adapters shorted the signals on pin 3 of the XLR connectors to ground. A direct RCA-to-RCA connection therefore MIGHT not have that noise issue.

Also, the fact that the KUBE's power supply has a two-prong power plug reduces the likelihood that noise would be an issue, because a ground loop via AC safety ground wiring would not exist (ground loops can cause high frequency buzz, as well as low frequency hum). The likelihood of ground loop issues between interconnected components having 3-prong power plugs increases if the cables connecting them are long and unbalanced.

Regards,
-- Al

My take is still to use the ISOMAX devices, but if Blue Jeans offers a return policy you could give it a try. My curiosity, like Al's, is how will the sound differ now that you are primarily running single ended. It appears that the benefits of the KUBE, both from yours and KEF's perspective, may outweigh the negative effects, if any, or running single ended.