OK, my old Rickenbacker 4001. I have not played this bass for a long time as it had developed, what I thought was, significant fretwear. I've just had them leveled and recrowned good as new, and the luthier told me it had weak output, even with the pickups adjusted extremely close to the strings. So I gigged it that night and the signal strength was no where near what I expected (or am used to compared to my Fender Jazz bass). Balance between neck and bridge pickup seems fine and overall tone is sweet during private practice sessions, but the overall output is maybe 60% of my jazz bass when gigged with the band. The bass is 25 years old, but has been well maintained and is in very good condition. Whats going on here? Whats the remedy?