Need 25 foot interconnects


I just moved around my equipment so that the rack with the preamp and digital sources is on the left side of the room and the monoblock amps are just behind the left speaker on a short platform on the floor.  I’m using a 15’ RCA interconnect right now, but want to move each monoblock to just behind each speaker — which means I need a longer cable.  The monoblocks are unbalanced RCA input only but my preamp can do balanced XLR or unbalanced RCA out.  Would a balanced XLR cable plus an XLR to RCA adapter work for this setup and be my best option?  Or should I just get a Belden (or similar) 25’ unbalanced RCA interconnect?  Or is there a better option?   

nymarty

@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. 

… so switched back to the Belles Aria Monoblocks, which I just bought.

The gear shaming is getting a bit difficult.

@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.  
 

The adapter that Emotiva sells does not do balanced to unbalanced conversion. It just dtops the negative phase signal, so you aren't getting any of the benefits of a balanced connection (significantly reduced common mode noise and elimination of ground loops). You need something like the Jensen adapter mentioned earlier in this thread to do a true conversion. 

But I'm glad to hear you aren't having hum problems. 

@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

Glad that worked out.
At least if it didn’t work out, then you would have had the cables needed for the Jensen isolators.

I have a bit of hum seen on a measurement spectrum from the TT, but when I play back file at +12dB I barely hear it with my head against the speaker.
So if it sounds good, then as they say say here, “You’re Larfin.”

Hopefully the next fellow or lady doing a search will find your thread helpful.
Thanks for putting a bow on it.