I don't think an upgrade to an Audioquest polymer cable will make much of a difference over your Monoprice polymer cable. A glass fiber cable might, but even that is questionable with the relatively short common lengths used in audio.
But rather than spend ~ $500 + for an Audioquest Diamond 280 strand quartz 1.5m cable, I would recommend the Lifeatec Silflex, where ~ $80 will buy you a 470 strand glass 6ft cable from the actual manufacturer of the fibers themselves.
Again, I don't know that you will notice a difference, but at least you will have spent relatively modest money commensurate with industrial/medical gear compared to a boatload of cash for inflated audio gear.
Steve