For anyone who cares...I modded a pair of AKG 501's with a CAT5 cryo cable. I started with a stock pair of cans that I loved except the lack of bass and what I perceive as a slight thiness in the midrange...especially at higher volume. I used three single strands of the cat5 cable and braided them...covered them in a dielectric, and set it up to burn in for a few days...I just finished tonight so it's a little early but...
It already sounds better...The bass is deeper and heavier without being overblown at all...I still wouldn't mind more but I think it's an improvement. The midrange does not have that slight thiness at any volume...even on recordings that leave a bit to be desired. And the top end seems similiar but may have a tiny bit more extension but...maybe not...I'll have to spend more time before I can say.
I'm going to break in the cable for a few hundred hours and then I'll post more impressions...hope this helps someone...I would have appreciated the input when this little project started...I just wasn't sure it would be worth the two nights work.
I converted mine 501 to accept balanced drive yesterday using two high quality shielded copper cable. It fit in the place of the old one and the original cable can be reinserted if needed. I can't comment on the sound quality though (or about the change in it), since I have heard it with its stock cables only for a couple of hours with my crappy sound card as a source. I had to convert it, since my amplifier have a 5 pin DIN socket for balanced drive and nothing else
Although I can say that they sound very good in they recent form, I was up till 3Am listening to it.
Also, I tried to get an opinon about the modding from AKG, but nothing really worthy came back. (The recabling took about 20 minutes, so it wasn't that hard at all.) Link here.