My '93 Epiphone Powerbass is a P/j setup. The pups are wired using the standard jazz scheme. Even though the neck pup is a split, it is wired the same as if it were a single. Is this just the way it was done? In use, it doesn't seem like I have a true volume/volume/tone. Does this have to do with the fact that two different pups are wired in a scheme designed for two identical pups? Is there an improved scheme?