I don't really understand your question. Are you saying it sounds OOP with both pickups on (switch in the middle)? Or with only the one pickup selected?
Either way, check your wiring. For the 36th it should be black/white soldered together, green/bare = ground, red = hot. If it sounds OOP in the middle position and that's not what you want you would reverse the red and green wires, making the red go to ground and the green your hot lead. Depending on your neck pickups polarity you could be OOP with the 36th wired correctly.
The volume pot will just take off some of the top end, I doubt that's the problem. I really like the 36th myself, and I don't find any holes in it's sound, so I'm guessing you're wired wrong somehow.