Hi, I've swapped the preamp in my bass with OBP-3 and am really surprised how bright this preamp is (compared to the previous one). That is: I cut all the treble on the preamp and still have to notably cut it at the amp to get a tone I like. Is there a way I can make it sound darker? I understand that one possibility is to add a passive treble control in addition to the preamp's one. But that would need another hole in my guitar, so trying to avoid this solution. The guitar is Yamaha TRBX-505. Preamp is OBP-3. Wiring is 500k vol, 220k balance, stock 50k pots for the preamp. Swapping the volume for 250k would withdraw some treble, but I think I will need it darker. Would adding a capacitor to the treble pot help? Or something like this?