Need 25 foot interconnects

@holmz  thanks for that advice.  I also read that Cardas makes an XLR to RCA adapter that I can order with the ground pin floated. Would that do the same thing as the Jensen? Or would I just lose the value of the balanced cable by floating the ground at one end?

with the Jensen, I’m assuming I’d run a long balanced cable out of preamp and then a short IC from Jensen to amp.  Thanks.

Thanks, all.  It sounds like the consensus is to stick with single-ended RCA cables of good quality and with good shielding. I’ve had no issue with the 15’ RCA cables I’m using now and they were fairly inexpensive. No hum, no noise.  Open to any suggestions on where to get the best cable at that length at a good price.  Will try Blue Jeans Cable but wondering if there are other companies that can do that length. I suppose I can also try DIY.

The trade off requiring long IC so far has been worth it. Getting everything off the front wall except for the speakers and corner bass traps has been a big positive.  Soundstage is deeper and wider and whole system sounds better.  Everything is just a little better placed in the music now.  

Spoke too soon about no hum.  It got really quiet in the house tonight and had a good listening session and left the earlier comment where I said "No hum. No noise."  When I stopped playing music and stood up, I heard a slight hum.  I got closer to the speakers and they just have a monotone hum coming out of them.  Going to need to troubleshoot the hum this week and figure out the cause.  Lots of things going on that are different -- also switched from low level subwoofer connection (interconnect) to high level coming off the speaker binding posts, so not sure if it's the 15' interconnect or the high level subwoofer connect that is causing the hum.  Maybe the hum is making the soundstage better.  ;-)

@dougthebiker for the win on solving the hum.  Thanks!  One of my amps - Schiit Vidar - was in the system after swapping out the monoblocks. When I disconnected everything from the amp except speakers and power, there was still that hum.  Couldn’t find my cheater plug to float the ground so switched back to the Belles Aria Monoblocks, which I just bought.   No hum at all. Dead quiet. Plugged in the 15’ interconnects from Schiit Freya + and still silent. Music sounds great!  Success!  
Thanks, all, for the recommendations on interconnects. Moving up to 25’ and just have to pick the right one for budget and SQ. 

@holmz  I was able to try your original suggestion.  I was on Emotiva’s website to buy a 12V trigger and they had XLR to RCA adapters, so I bought 2 of them.  I hooked up a pair of 20’ balanced XLR cables to my preamp, added the adapter just before my amps and connected a short run of RCA cables between the adapter and the monoblocks.  Success.  No hum, no feedback, just a silent connection.  Sounds petty good, too, when playing music.  
Thanks, all, for the help.  
 

@holmz  I think we’re all right.  Let me explain.  I set up the balanced cables out of my preamp (Schiit Freya +) and ran them to the Emotiva XLR to RCA converters to another short RCA interconnect to Belles Aria Monoblocks and, eureka, no hum,no noise, just music.  Then, about a week ago, I swapped out the amps for my McCormack DNA-1 with same cable setup. Not good. Audible hum coming from the speakers as soon as I turned on the amp.  Tried the same test with a Schiit Vidar amp and same result — audible hum.  I then swapped out the balanced cable  with adapter connector for a long RCA with an RCA-RCA connector to the original short RCA cable and no hum.  Just silence and just music.  
I don’t know what the Belles does that made it work with the XLR-RCA setup but I’m convinced now that I need to go with just a longer quality unbalanced RCA between preamp and amp.  (Or get a fully balanced amp.). Going to hold off on that for a while to play with some new to me speakers — Vandersteen 3A Sigs.