Guitar Pre amp humming problem

[ali_moinuddin]

HEllo friends,
i tried to make Guitar preamp I did finish making it on a PCb the resukts are impressive but with few problems

1. A lot of humming 2
the voltage drops from +12 0 -12 to +9 0 -9 once i connect the power to the pre amp board.


Need help to correct these problems

thanks

 

[ali_moinuddin]

here is the schematic of the Pre Amp