RCA Cable Quality

Important to understand.... an audio cable can't ADD anything to the sound. Not possible. It can only detract. Once understood that  resistance, capacitance, inductance are the important factors then an intelligent decission can be made to properly fit the requirement of the equiptment it's plugged in to.

The only time an improvement can occur is if the cable you are replacing is inferior in some way.

This has nothing to do with spending more money on some exotic cable made from space age unobtainium. There are inexpensive cables that will work equally as well if you match them properly.

Good for you (and your wallet).  Frankly if I couldn’t hear significant differences between interconnects I’d be concerned about my system’s transparency or my ears, or both.  In my system interconnects make a bigger difference than speaker cables (although my speakers are an easy load that I think affects that), and I think the digital cable makes at least as much difference as the interconnects if not more.  Just my experience in my system and obviously will vary. 

I have never heard any differences between cables. I did buy five pairs of Audio Quest Silver Extremes for $450. They look nice!

I've had MIT shogun RCA cables since the ninities  Can even remember what I payed for them But what I really like about them is their high quality locking banana connectors  They grib like nobody's business 

Same experience as OP. Tried a bunch (on loan from local hi-end shop), not an iota of difference. Same for speaker cables (AWG14 vs 5–6). So as long as it has mechanically decent connectors (e.g  Blue Jeans), I'm good. Speaker is bare wire, of course.

If someone questions quality of my components, look at my virtual system. Not stratospheric, but not entry-level either. So going from entry to something "better" has best shot to show *some* differences, but it doesn't. Tried it enough times not to bother anymore; remember definition of insanity.

As I mentioned before, differences in recording styles are MUCH greater, so "optimizing" cables is a fools errand. Or are the cable guys changing cables depending on which recording they play? LOL!