Balanced interconnects vs. Analog

The geometry of a cable has more to do with canceling RF and EMI over single or balanced cable such as a braid or twisting the conductors around each other. Insulators and shields have much to do with this, and a well engineered cable with no shield can be very quiet. Many cable manufactures design or geometry of their actual cable is the same cable whether they are selling it as a balance or single ended RCA IC; they only change out the ends. Yes, the way they terminate the ends is different obviously and it varies on the geometry of the cable. I've used single ended Kimber's KCAG which has no shield laying across power cords and picked up no noise; that cable with balanced ends is the same bulk cable.

Balanced cables are primarily used in studio or on stage because first that's the preferred end by the manufactures of the equipment and mic's, it's a better end as it locks into place so no worries the cable will pull out if someone snags a cable and a balanced cable can drive the signal at no or little loss of the signal over a single ended design when we're talking about a cable running over 20 feet or more. A lot of gear is not a true balanced design and some gear even with XLR jacks are not a balanced circuit. Most pro audio gear is a balance circuit because it is expected cables are going to be very long. The point I'm making is if the equipment is not a balanced circuit, it doesn't matter if the ends on the cable are RCA's or XLR,s.

I personally have used many of the pro cable lines on stage and have dragged them home and tried them on my home system so I do have personal experience. I buy my studio cables in bulk and terminate them myself and I've tried various XLR manufactures as well. I've compared them to my home cables and they're not in the same league and they shouldn't be for the cost difference. Using my pro cables on my home system I prefer my RCA - single ended cables and my gear sounds best with balanced cables because my equipment is of balanced circuit. My single ended cables are all Clear Day Cables and they are very good cables for the money. Switching over to my balanced cables which are also Clear Day and WyWires it is night and day difference between the much lowered priced pro cables. The pro cables don't sound bad at all; actually they are very musical and forgiving on poor recordings. They're not as revealing as higher priced cables, which I feel they are more of a tone control over better cables. Some may actually prefer their softer or warmer balance on some equipment and likely wasting their money spending more because their system isn't as revealing or maybe a little forward or bright to begin with. I also find pro cables don't have the openness, air or stage of more expensive cables and this personally where I find its time to pull them out of my system. I can live with a softer cable because much of the music I enjoy isn't recorded very well, but when the stage is smaller or flat that's where I'll stick with my better cables. I'm a big fan of Clear Day Cables and they do many things very well and a great value. The pro cables don't begin to touch the Clear Days, and they Clear Days are much more open, but that being said that's where my newer WyWires really pull away. I have both balanced Clear Day and WyWires. The WyWires are extremely open and the Clear Day by comparison sound closed in which they're not.

Everyone's going to have their own opinion on the sound of cables and that's the way it should be. It really only matters what ones ear likes and how much money ones willing to lay out I suppose. Good to read others opinions and learn from others as well I say. Cheers.

Here is a link that Paul of Clear Day Cables sent me to help me understand the difference and the advantages. 

https://youtu.be/BQtMFsw_3Hg

N

Also, do you want cables that are pure or mostly silver or mostly copper? This does matter and very much depends on particular system and taste. In my solid state system with analog source I use both silver and mostly copper alloy cables in the chain and silver speaker cables. I have warm sounding speakers. It can get a little complicated.
By the way, I used to use DiMarzio pro RCA interconnect, excellent for analog source, good overall balance soundstage and bass, not cold not warm, just about right.

You can buy a 1m used pair of XLRs and resale them if they don't work out.  

I suspect that the correct model designation of your W4S integrated amp would be STI-500, not SSi-500. If so, it is described as a fully balanced design, and the following statements appear in its manual:

The line-stage within the integrated doubles as an unbalanced to balanced converter which provides a balanced signal from unbalanced inputs.

The Neutrik XLR (balanced) connectors are the finest balanced connector on the market, and are the best possible option for connecting your amplifier to your sources.

The description of your Oppo BDP-105 states the following:

The stereo output offers both XLR balanced and RCA single-ended connectors. The balanced output features a true differential signal path all the way from the DAC to the 3-pin XLR connector.

Based on those statements the answer to your question should be clear. At least insofar as which kind of interconnection is likely to provide performance that is most accurate, i.e., that is most true to the source material. Greater accuracy may not always be subjectively preferable, of course.

In general, in a home audio system my belief is that when choosing between balanced (XLR) and unbalanced (RCA) interconnections the designs of the interface circuits in the specific components that are being connected, and also the internal grounding configurations of the two components, are likely to be more significant factors than differences in the intrinsic characteristics of the cables that may be used.

Good luck. Regards,
-- Al