17' unbalanced cable v balanced with ISOMAX

I recently bought a pair of KEF 107/2s designed to be used with a 107/2 KUBE, an active crossover with equalization. The KUBE has only RCA connectors. I've been using 17' Blue Jeans balanced lines from a Cary 11a processor to a Proceed Amp 3, and can continue to do so if I use Jensen ISOMAX transformers at the amps to transition from XLR to RCA. Without the ISOMAX the XLR/RCA transition introduces an audible sizzle to an otherwise inaudible noise floor.

A 17' unbalanced Blue Jeans LC-1 cable would eliminate the need for ISOMAX transformers and be a neater setup, but I don't want to sacrifice audio quality or add noise.

Advice, comments, recommendations please.

db