Need 25 foot interconnects

I dunno @nymarty - I would do the XLRs either yourself or from some place like BlueJeans with a star quad shielded wire and the XLRs.

Then just use the Neutrix to XLR jobs which are $10-$15 each.
If there is not hum you are done. And if there is hum then try the Jensen’s isolator.

That is assuming that the Cardas is the same as a Neutrik in that it adapts and is not a balanced isolator.(???) so the Cardas should be the same?? 

Basically it’s a couple of baby steps.

• Cable+adapter and no hum = job done.
• Still noise(?), then slip in the isolator.

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?

Yep you lose the balanced with the floating ground

• The adaptor gets the signal to the amp.
• The balanced cable allows you to go to the isolator if there is hum.
• So you can use the isolator later if needed, or if you change to mono blocks that have a balanced input, then you already have the XLR cable.

I would do that before going to a high $ single ended cable, as it has a much higher probability of mitigating hum and noise… having Star-quad balanced + shield + isolator is close to bullet proof.
Not quite as good as a balanced amp, but as close as one can get.

I'm running 20' RCA cables and it didn't make a difference in sound when I used a 3' RCA cable, I compared them in the same room with the same equipment. I'm not saying your balanced output may not sound better, but I don't think that going from 15' to 25' with RCA is going to make any difference, unless you are picking up noise on your RCA cables.

^Entirely likely as well.^
Which is why I first mentioned the star-quad with the ProFi ends.
And coax is also an option.

If that doesn’t work, then desolder and go to balanced.
But he stuff is only $1/ft or less so it is probably just cheaper to order it if doesn’t have a soldering iron.

Maybe you could try one amp (then the other) using an RCA double end male to hook your two shorter cables together…??
If that works with no humming, then just order the right length with RCAs.

I have been presented with this issue a number of times. You are doing a split in the right place. I have done both RCA and XLR. I would recommend the highest quality of RCA you can afford. I know this is painful. I do not recommend adding any converters. Native single ended is very very likely to sound the best, certainly at 25’.

Your system is going to sound much better getting the chest out from in between your speakers. I suspect if you hang a really thick rug below the windows, that will greatly improve imaging. Tube traps in the corners would probably also significantly improve the sound. An area rug in front of speakers until nearly your listening chair. Little corner traps (cheap and innocuous.

Also, this gives you the option of using super short speaker cables… this is reported to me by some folks I really respect to slow a really big jump in performance. You have to use a really short, high quality speaker cable… 1.5’ or maybe two feet. It is supposed to really improve the presence of the system. Something I have wanted to try, but never have been able to.

Mogami XLR cable is about as inexpensive as you can get, and still get decent quality. Probably cheaper than a lot of RCA cabling.

B

You need balanced amps to make any difference with balanced cables. Necessity is determined by RF noise in your playback space and sensitivity to it of your electronics.