Bringing back an old thread!
So I recabled my 880's with mogami cable and canare connector, like the OP but did dual entry, and I am a happy camper. I highly suggest this mod for anyone who has ANY beyer phone be it 770 880 or 990. Its just a real shame that beyer, for a company making a good, medium tier, phone to skimp so much on the cable. After taking apart the phones and checking out the wire, it appears to be shielded with the lacquer used on bell wire, so each set of wires are barely insulated, and forget about shielding.
Now the soundstage has opened up quite a bit and I feel like the entire bottom end on the frequency range has improved, opened up. Highs seem less jarring, sibliant, even at pretty high volumes. I started this mod not really thinking too much of it, as I generally don't subscribe to changing cables making too much difference, I use ofc 12g in my speaker setup to be safe, but nothing too fancy. I felt the mogami was reasonably priced ofc, and seemed much better than the crap beyer gave us.
So for 12 bucks worth of cable I got me quite an upgrade. One more note: it seems that the phones now can handle more volume with ease, as before the recable, using my ZVM headphone out, the highs used to be pretty harsh, leading me to want to turn down the music, now I just want to rock out cuz the beyers sing with more juice. Highly recommended, thanks Jam Master.