[Ryan84]

I was hoping to get away with using a 15ft TRS Aux cable linked below with my DT770(250ohm) cans and connected straight to my Soundblasterx G6 DAC, since it reaches perfectly from where I'm sitting from my 65" TV. My other 10ft aux cable doesn't quite make it.

https://www.amazon.ca/gp/product/B00LBJ780O/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&th=1

But isn't it best to keep the Aux cable 10ft or under to prevent audio degradation? What's the max limit before that even happens? And should I also factor in the 6ft USB(2.0) cable and Toslink cable length coming from the back of my DAC and to my TV or game consoles?

 

[Davidv100]

I know nothing about headphone cables - but I am also shopping for custom made long cables (about 20ft / 6m).
I read (but I am obviously no expert) that balanced cables have no issues with longer lengths (FWIW).

 

[gimmeheadroom]

There is no answer to the audio cable question except "as short as possible." As @Davidv100 said, balanced cables out of good amps can tolerate longer runs.

USB cables definitely have working length limitations (5m is stretching it) but that is not related to the analog side cable length.

The only way to know for your setup is to use a normal length headphone cable, let's say 1,5M and compare with your long setup. If you can't hear a difference, then done.