Really Long XLR

What crustycoot said You cannot go wrong with Mogami. 

+1 for Blue Jeans Cable, I have had several balanced & unbalanced cables from them & always been pleased with quality & price. Their website has some great articles on cable construction, trade-offs, and choice.

 Markertek will make you whatever you want. Canare and Belden....

ooooh, that's good to know, @winoguy17 !!

I'll be curious to know what you settle on and what you think of the results. Long runs are what XLR cables were made for. Nevertheless, a long cable run should be more revealing of differences between cables than a much shorter run. I think these long lengths are how cables should be compared. At 50', a double blind test should be easy to pass, right? If you're struggling to hear a difference at 50', it's going to be a much bigger struggle to hear a difference at 5'. 

There should be cable manufacturers jumping at the opportunity to loan you the long cables in this situation so you can compare and  hear the differences that are going to be obvious. 

Once again, thanks to everyone for your comments and suggestions, One thing I do find surprising is the strong support for cables costing $1 - $2 per foot. Don’t get me wrong, I’m not looking for a reason to spend more than required, but for the main cable carrying the signal from preamp to power amp, I am truly surprised there is anyone suggesting this is the place where a $50 - $100 cable is the appropriate choice. This is going to be way more difficult that I thought. Luckily, I don’t need to make the decision for several months. I do like the specs and cost of Audio Envy O’nestian Matched pair.  OCC copper. They will build a 45 foot pair for $1200. For the DIY, so many to choose from.  And of course there is the Nordost Odin knock off from China.  🤣🤣🤣