Maybe he has a special workbench that gripes and locks onto the cups by the six hexagonal (driver holding) screws, in order to immobilize the individual cups when removing the gimbals (he did told me on the phone that he disassembles it "completely"), milling and enlarging the cable entry hole, and doing such heavier deeds that requires the headphones to stay firmly into place? And it's the six "tentacles" of this workbench that would inevitably leave behind those marks? Anyway, that's one hypothesis :P hope it's not too bizarre sounding.
Thanks MuppetFace for your heartwarming comment!
Here's the two headphones I've been listening to exclusively lately:
But I've had small problem with my Grado HPA-1. It runs on two 9 volts battery and I've got four of them. Lately one of them suffered some kind of energy memory loss, it won't charge enough power anymore and last only 5 minutes in the amp after a full charge. So with three batteries left I can really only function on one pair, since the amp requires one per channel, and I get interrupted everytime they require charging. Luckily I bought a protection plan (which I rarely ever do) if I can't save my fourth battery.
Anyway, it remains that for now I still need to listen to a second device from time to time because of that, and it's a bit annoying yeah. My GT40 doesn't sound the same as my HPA-1, it has less authority and sounds brighter.
Here's a nice picture I took accidentally while trying to capture the inside of my HP-2i cup, with the use of a flashlight.
Edited by devouringone3 - 8/17/12 at 4:58pm