Interesting cable experiment; surprising results....

Hello all,
My large and whacky multi-zoned monster of a stereo at our bakery/cafe has been long over-due for an overhaul. There is one blown speaker in the most important zone; the wires to the front patio speakers were blasted by the roofers; the speaker-level volume controls in the kitchen are futzy and sound terrible; our awesome Sansui 9090 at the bar needs need a good De-Oxit session; etc, etc. But mainly I want to be able to add a turntable so I can spin records on days when I feel like being sociable after baking all night. The problem is that one set of amps and zones is very distant from where the turntable will live. Currently the two parts are tied together with two Sonos Connects. And the last thing I want to do is to play records with my lovely custom Rega with an Apheta v.2 cart and digitize the sound so it can be played throughout through the crappy a/d and d/a chips of the Connects. So I’ll be relying on several long runs of interconnects, one of which will be 150’ or so.
My solution is to use a good quad-shield RG-6 coaxial cable. I bought the best quality RCA compression fittings I could find and a 500’ spool of cable. So today I’m testing my technique. I was able to free the inner end of the spool and I put connectors on each end. For a quick and dirty experiment I’ve got one channel of an 1/8" mini-jack to RCA Y-adapter running direct into my integrated amp, and the other end connected with a barrel connector so that all 500 feet of cable is in line with the other channel. (Source is an iPad/Tidal) A little adjustment to the balance and..... I can’t detect any difference in sound quality! I was expecting the high frequencies to be attenuated, or a severe roll off in the bottom end or SOMETHING, but it sounds just fine!
Of course I would normally be using a good DAC, etc. So I HOPE that my Accuphase and ATC combo would be revealing enough to show some detriment to using a 500 foot cable for one of the channels, but I know it won’t be much! Ah well, just thought I’d share and maybe get a few comments! Thanks for reading. Here is our system as it is now: https://systems.audiogon.com/systems/6656
~Oran