30 foot long Balanced Cables to Balanced/RCA Adapters into Amp's Stereo RCA inputs?

There is nothing wrong with using balanced cables. 

Do you really need 30-50ft? Shorter runs are always better if you can - 10 ft and under for the lowest possible cable resistance.

Regarding jacks on any system, lighter cables with a solid fit are ideal. You don't want a very heavy cable. Some premium (very expensive) cables may be much heavier...

I would not use unbalanced runs for such a long distance, which is what you'd end up with if you used simple passive XLR to RCA adapters at one end. You're very likely to pick up a lot of audible interference.

You could use a transformer-coupled adapter, but that will affect the sound to some degree. Whether or not it is audible would depend on you and your system.

Alternatively you could use an active converter, which also runs the risk of having an audible impact on the sound depending on the converter.

Also, even for a shorter distance, you would need to know what the right internal wiring should be for your XLR to RCA adapters, unless you're using a transformer-coupled adapter or active conversion. You may need to ask OPPO or find someone else who knows the right configuration.

Thats very long you will loose some sound quality however with adapters.

For a run that long you'd really be well served to run it balanced. A regular XLR->RCA adapter at one end defeats this. So while not what you want to hear, if you really need to run that long you need electronics which accept balanced as well. One of the great virtues of true balanced connection is that long low level cable runs work well with a lower noise floor than thru RCA. 

If you use an RCA cable make sure you use a shielded design. Kimber Hero comes to mind but there are less expensive ones out there. 

Little long in the tooth for a single ended run. The XLRs will get you there BUT delivering a signal with everything it collects along the way. Does that make good sense? NOW if you had an amp that had balanced inputs.

I’ve seen a few RCAs at 20 plus feet for subs and few other things.. It CAN work, you just need to be aware they can pick up noise.. Signal loss on the other end of single ended cable.. Roll off, ay..

I think there is a way to modify the run to work better by using a shielded cable construct in leu of the noise canceling hot/cold. There is more than one way to reduce EFI, RFI. Roll off is a different story.. Suppose to be a GOOD source right?

Regards

thanks everyone,

I finally understood a simple XLR/rca adapter defeats the advantage of using Balanced,

so, it's balanced for 35 lf

into this conversion box, which maintains the advantage of balanced for the long run.

https://www.amazon.com/gp/product/B003S7T49K/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1

last 5 lf rca out of the clearboxproto to amp's rca in

btw,

I had to choose between 22 awg OFC

or 16 awg Pure Copper

considering the 35 ft length, I chose 16 awg pure copper.

I read somewhere that the % of purity between Pure and OFC is very slight, the difference in conductivity hard to measure actually; whereas I would think, the difference in conductivity 16 awg to 22 awg is definitely measurable at 35 lf.

interconnects; speaker wires (16 lf 13 awg/leg); speaker wire spades are all OFC

speakers are horns/15" woofers, 16 ohms from 1958, efficiency over 100; amp has 16 ohm taps.

cayin tube amp is 45 wpc, so volume should not be an issue, noise free and modification to frequency response the culprits to listen for.

under the floor there is no machinery, I will see if/how many electrical feeds to nearby wall outlets I cross. Original to 2 wall outlets BX; 1 new 15 amp sep ckt for the amp is ROMEX I presume

@elliottbnewcombjr that ART CLEANBox Pro you linked to will work but it will also introduce distortion.

From the specs (read this from the perspective of what is introduced at a minimum):

• Frequency Response: 20Hz to 20kHz, +/-1 dB
  
• Total Harmonic Distortion: <0.1% @ 1 kHz

nekoaudio

Thanks for the info.

This whole thing is going to be: fun/informative/PITA. I already pity my knees, back, brain, ears, and relationship after I send Donna into the crawl space. I am lucky, she loves me, music, has been there all the way for 31 years. Without hesitation: "Get It". When she want's shoes, I remember that, simply say: "Do you NEED them?" 

I decided,

1. hook to Video system to see the menu
2. factory reset
3. firmware update.
a. do not watch or listen in video system yet.
4. move to music system, direct to Cayin Integrated Amp
a. compare to existing Sony Carousel (repeat, don’t laugh yet)
Cassandra Wilson; Sophie Milman; Nina Simone; Santana; Euthrymics; Friday Night 3 guitarists; Meeting by the River; Blue Nile; Micky Hart; WAR ...
5. move back to Home Theater for music dvd shootout:
a. James Taylor Live at the Beacon, early 5.1, very well done,
https://www.amazon.com/James-Taylor-Live-Beacon-Theatre/dp/1573300934
b. Sophie Milman Live In Montreal (wish I’d been there)
https://www.amazon.com/Sophie-Milman-Live-Montreal/dp/B001EGG5RG
c. then, Jurassic Park, hear the rope slap the water in the beginning, move on from there

IF the Oppo beats my existing Sony Blu-Ray then I HAVE to try leaving it there and the long run to the music system. Simply HAVE to.

Oppo, long run: still beat the Sony Carousel? Any perceived .....?

NOW, FINALLY: return the ART clearboxpro for better transition box like you and Ralph suggest is better?

@elliottbnewcombjr you may not notice any audible degradation with the CLEARBox Pro, which would be great. Give it a try. I have no idea what gear you are currently using. For what it's worth, the XLR <-> RCA conversion solution I ended up going with myself, chosen by reviewing specs and measurements, was about $1000.

Ah, the best made plans of men and mice.

What I learned: How smart I am!

Huh? Yes, smart enough to know a whirlpool bath combined with a mixture of 2 Naproxen and 1 Aspirin helps relieve the pain from the worthless job of hunching over in the crawl space for this worthless attempt.

All went well: into Video system. factory reset, firmware update. 

Watched James Taylor mentioned above, excellent video and audio.

Tried Blue Nile CD via 35 ft XLR to Music system. Whoopee, works!

OH NO, infrequent popping noises. I had read that some of the early firmware update(s) were to eliminate popping noises. Latest firmware incorporates all prior fixes. Yet, there they were, before, and infrequently/randomly within the music.

Out, into Music System, interconnects direct to Cayin Integrated Tube Amp. (both Oppo and Cayin have remote volume).

Blue Nile: great, subtly better than current Sony Carosel.

..................................................

How to describe the difference? You hear the same things, it's all there from both players, yet the Oppo is subtly more precise, not sterile, just like your ears are working a speck better. Perhaps it's the timing, and better coherence of fundamentals to their overtones, I need more time to listen.

The image that comes to mind is rays of light passing thru a Chinese finger Trap. (we loved these things as kids in the 1950's)
https://en.wikipedia.org/wiki/Chinese_finger_trap

Tight, no light gets thru. Loosen a speck, precise rays of light get thru (Oppo), loosen a speck more, the same light becomes less focused (lesser players).

More listening coming up today, some well known, some SACDs.
...........................................

Was the problem the clearboxpro? Would the problem be gone if I used the Jensen? Given the history of firmware to solve pops, I think not.

I'm glad I tried. Thanks to all for their knowledge and advice.

Elliott