17' unbalanced cable v balanced with ISOMAX

Al & Clio,

Perhaps I've made too big a deal about a kluge. Each ISOMAX box is only 3" square and 2" deep, so they are easy to tuck away and completely effective in restoring the noise floor to inaudible. If they distort the sound, I was unaware of it. OTOH, for $65 I can try unbalanced with the BJ tech-wrap (or $40 without the wrap). Not a big deal.

db

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.

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

Al & Clio,

Right now the 17' balanced cables run from the Cary 11a to the Proceed Amp 3. When I tried a KUBE 200, I ran the balanced cables from the 11a to the ISOMAX, unbalanced from the ISOMAX to the KUBE, and unbalanced from the KUBE to the Amp 3. That seems a bit of a kluge, but it to worked. I was wondering about running 17' unbalanced directly to the KUBE without ISOMAX units.

Clio's point is well taken. Pedal notes that were previously inaudible with the 104/2s became audible with the KUBE. Those pedal notes are very audible with the 107/2s even without a KUBE, but the 107/2 KUBE is said to provide a needed mid-frequency crossover function that yields more accurate sound.

db

Per the other thread referenced by Al, if you are getting good results with the ISOMAX devices I would continue to use them.

DB, although I recall our recent related discussion, I'm not sure I understand your question. It seems apparent that you are asking about changing the connections between the outputs of the KUBE and the inputs to the Proceed to unbalanced LC-1 RCA cables, but I don't follow your description of the present configuration, that you would be changing from.

In any event, I suspect that the answer will be that there are too many variables and unknowns to be able to predict how well the long RCA cables would work, with respect to either noise or sonics.

Regards,
-- Al