audenum,
Hah! I have to laugh -- I was in the first shippig batch of Cracks, so obviously I'm not in a rush to get it done. :-)
I rather enjoy the buildiing -- everything from the wood and metal work to the finishing and appearance details and so on.
I actually had teflon tube sockets in it and then recently replaced them with Azumas, and only because in my opinion and for my purposes, I prefer them. The point is that building, taking my time, and making sure everything is as right as it can be, is all part of the journey for me. That said, with both my 2-channel loudspeaker systems down and in transition, I'm really wanting to get the crack done now.
To answer your other question, yes, the switch is the filament voltagee switch. It's just an NKK mini locking dpdt toggle and sits between the rear mounting screw for the front tube and the air vents. Tight squeeze, but clears everything and won't interfere with the speedball board once it's in place.
I was checking out the Quarts again this morning and noticed that like all other German headphones, they actually did make the earpiece molds wth braille letters for left and right, which is a nice little touch I really appreciate. All the Senns I've ever had have a braille "L" on the left side, and the AKGs I've seen and own have a small raised dot on the left earpiece, but I have no idea about the Japanese and American cans, though I know the Sony MDR-7506s I used to have did not have any marking, but they were also single cord design.
I, for many reasons, wsh I still had my old black and yellow Sen 414s (originals, not the "upgraded" version -- but of course I had no use for braille in those days, so don't remember. Anyway, point is... nice touch and I appreciate it.
Hope to mae more progress today...
-- Jim