Instead of creating my own thread regarding modding F1 as noted above and adding a balanced cabling, I just decided to bump this (VERY) old thread to respect those who started it.
I really appreciate revival of Sony F1 interest in this new thread:
http://www.head-fi.org/forums/f4/son...s-pics-284563/ It is this thread that pointed me to this old thread to really change the sound quality to be more open and dynamic.
WARNING: DO NOT PERFORM THIS MOD IF YOU ARE NOT COMFORTABLE WITH BASIC SOLDERING SKILLS.
It seems that Sony has decided to GLUE the screen in place at three lip/slide points. To loosen the glue's grip I used a 2mm flat tip screw driver. Insert it between the screen and metal housing as deep as you can put it without too much force then lift gently until you see the screen shifting little bit. Do this all around about 1cm apart. You might have to go around the screen 2x-3x before you can twisted open or they will just pop open. Once it's loosen you will NEVER-EVER have to use this method since the glue's seal will be broken permanently.
Once the screen is completely open, you will notice a notch. On the left cup that notch is pointing south and on the right cup the notch will be pointing north when you have to put it back. Placing everything back is easy...just place the notch along respective position for left and right cups and just twist clockwise.
Here is picture of left driver exposed: (yes, I cut the wires already)
Here is picture of right driver exposed:
Further optional modd to increase dynamic and clarity (IMO):
I removed the driver housing and took off the silver coat around the inside of the housing facing the ears. It just peels off easy with rubber tension around the lips.
I noticed there is paper screen around the rim of the driver housing. I decided to remove it to put less restriction from the drivers as well as more air-flow inside the driver chamber. (At lease it sounds like a good idea at the time and it did work out better in the end). IMPORTANT: YOU MUST PUT THE SILVER COAT BACK ON OR YOU WILL HEAR ALL TREBLE.
For the final balancing act:
The positive terminal is the soldering connection immediate left of the puddy like substance in the mid section and the negative terminal is immediate right of the puddy like substance. As you can see from this close-up...I totally obliterated the comp network by scoring the single trace and removing the two registers around the two + and - poles.
After this...you just wire it to your balanced standard (two 3pin XLRs or like me, 4pin XLR).