Hello everyone, today I am going to do a walk through for rewinding a set of Fender 60s Jazz Bass pickups. The neck pickup has stopped working so the customer opted to do a custom rewind instead of trying a repair. Both pickups bobbins looked to be in good shape, but the lead wire connections have become brittle and fell off. These pickups are a good candidate for a Sullivan Music Equipment Jazz Bass Pickup Custom Rewind. As you can see in the image below the leads are loose from the bobbin and have wax flakes around the pickup. Our goal with this set of pickups is to darken the tone of the bass since it will be used primarily for blues and some heavy rock music. The customer has chosen to rewind with vintage 42 AWG Formvar wire and to over wind the pickups to 10,000 turns on the neck and 10,500 on the bridge. This will be around a 10% to 15% over wind from the stock Fender 60s jazz bass pickups. It should be noted that the bass guitar is very bright sounding to start with and the customer is trying remove some of the harshness of the bright tones. The original pickups measure 7.6K Ohms on the neck pickup and 7.9K Ohms on the bridge.
Jazz Bass Pickup Rewind: When repairing a pickup I like to use a cutting board as a work surface and a large magnifying glass with a bright light. I also use an assortment of hand tools you will see as we walk through the repair. Above the work area you can see some of our test instruments.
Jazz Bass Pickup Rewind: First I remove the wire leads from the bobbins and make a cut in the coil wire at the center of the bobbin, then I pull the coil wire off in layers. When pickups are wax potted like this set it makes removing the coil much easier. You have to be very careful when cutting the coil wires or you can scar the bobbins and create a jagged surface that can break the new wire as it is being wound.
Jazz Bass Pickup Rewind: An hobby knife is the best for cutting the coil wires as it is thin enough to reach inside the bobbin, box cutter type razor knife have a blade that is to wide and they do not fit into the bobbin.
Jazz Bass Pickup Rewind: It is important to clean the bobbin to a like new condition, not only because it make the pickups look better, but it assures the success of a cleaner and tighter coil.
Jazz Bass Pickup Rewind: Fender mainly used two different type of coil wire in the early years ( Formvar and Plain Enamel) mainly because of availability and cost. Well it turns out that those types of wires can add to the tone of the pickups as they age and this why so many people request them in the pickups.
Jazz Bass Pickup Rewind: Hand winding the pickups is also known as “Scatter Winding” the coil. Machine wound pickups can sound dull and lifeless because they introduce capacitance coupling within the inter coil due to the wire being wound so perfectly close together and in parallel lines. Scatter wound pickups eliminate this capacitance coupling by using a winding pattern that randomly overlaps the coil wire and reduces the parallel lines with in the bobbin. There is a lot of information on the internet about this subject for those who would like to read more about it.
Jazz Bass Pickup Rewind: When winding a pickup we have found that keeping the winder at about 600 RPMs produces a tighter coil with less wire bulge from the centrifugal force. It also allow you to apply more tension on the wire without stretching the wire and making it thinner or breaking the wire, of course it does slow down the process, but the end results are worth it.
Jazz Bass Pickup Rewind: Here you can see the final assembly of the pickup, if you look closely you can see the coil wires overlapping each other and if you look at the ends of the pickup you can see how the shape is not completely parallel to the magnet poles. The contour of the coil shows that there are many overlaps as it was wound. Note: Pickups that have coils contours that are too parallel to the magnets or that are uneven on both sides shows a lack of attention to detail form the winder. Below are good examples of how a pickups should look after winding.
I will post sound clips of the bass as soon as possible.