I use the stock cable with no issues personally, I was never a believer in Break In but headphones have allowed me to hear things that were not audible with open air speakers, There were some definite improvements over time, I am leaning to My amp as my bass improvement............It was just shocking to hear such deep bass as clearly as I do now
I have another amp on the way to audition it is supposed to be the cats meow with special ordered iron that supports a range of cans from 32 up to 600 ohms imp, it uses the Darling circuit design 3/4 tube watts.....................should be interesting
Now for the challenge. Get an A/B switch and compare your amps with one set of headphones.Be very careful to exactly match the volume in both amps as to what comes out of the cans. Be prepared to be surprised.