I've had to replace the pads on my Sony 7506 cans as well. I was very impressed with the parts that can be replaced on these cans. The packing includes an exploded diagram of the parts.
I love my 7506s. And I have a recurring event on my calendar to remind me to buy new pads every 2 years. That's almost exactly how long they last. I've tried 3 brands and they've all lasted almost exactly 2 years. The original Sony pads also lasted 2 years.
