To the OP, the cable myth is not a myth to me, my ears, and my hearing.
I have tinnitus from a car accident and irresponsible brother (year before he became a felon) when I was 13 and it comes and goes, but has become much less severe from using higher-end audio.
When I received my hd580 high performance cable, the clarity improvement was marginal.
When I received my Ultrasone Pro 2900s it came with 2 stock cables and a toxic cables viper silver-lined copper cable. The stock cables would eventually create tinnitus after listening sessions and the toxic cable made the signal smoother and more resolute, leaving no tinnitus after a listening session. The Ultrasone Pro 2900s are notorious for being too bright, so I am glad that someone bought the toxic cable to go with the cans.