Yes, any wire will work for the jumper.
Essentially, if you have any DC voltage at terminals 7 and 9, then the 100uF capacitors have to charge, and they charge through the 2.49K resistors. How quickly or slowly this happens depends on a lot of variables, but if everything else in your amplifier is up to snuff, I would go ahead and test for sound.
The one thing you might want to do is to reheat the joint on the TRS jack where the two 2.49K resistors meet the ground wire.
-PB