Now I’ve decided to go for a Fender Jazzmaster circuit and pickups, I’ve begun to sort out the electrical components required. Since this is a first-time project I’m not very confident in my own skills; furthermore I have a smaller Squier Stratocaster body to work with, and don’t really feel the need to have the full Jazz circuit with all those separate rhythm and lead controls. It’s going to be a configuration of two pickups, a master volume and tone, and a three-way selector switch; similar to the Telecaster I suppose, but with those distinctive pickups (which will be the most expensive and therefore will probably be the last parts I’ll buy). With the structural aspect of the instrument up to a satisfactory standard (that annoying bridge screw exempted) I now feel ready to start the wiring.

Firstly I ordered a new scratchplate. I opted for black instead of white which was cut for two humbucker-sized pickups, instead of the usual set of three holes for single coils. For convenience’s sake, I’m sticking with Axetec for all my components; they seem to have everything I need from control knobs to cables. Their delivery times are fast too.

As you can see above, there are cut-outs for two humbucker-sized pickups (which match the Jazz’s pickups in size closer than other single coils, ironically), a slot for the pickup selector switch and two holes drilled for control pots. The usual Strat scratchplate contains three holes for controls, but since I’ve not yet decided on more than two control knobs and may need to extend the pickup cutouts outwards anyway, I actually prefer the ‘plate to be cut this way.

Fitting the scratchplate

Fitting the ‘plate was straightforward enough: some screw holes didn’t align properly (the Fender models have eleven screws while Squiers have eight) and the edge of the ‘plate butted up against the bridge on the high E side but some patience with a screwdriver and a couple of mm of plastic shaved off with a craft knife solved those. The reverse side has foil glued from pickup hole to pickup hole, in addition to surrounding the holes where the controls go; more than is found on the underside of the guitar’ original scratchplate actually. Since feedback was a concern very early on (I’ve heard that Jazzes are notorious for this), the added extra shielding material was a nice touch on the part of the manufacturer. So far so good.

For the time being I have a pair of Strat-style single coils borrowed from another (broken) guitar and fitted for test purposes while I save up for new ones; they sound awful but will at least allow me to test the wiring. The Jazz pickups are shallow, but roughly as wide as double-coils, despite being single-coil wound; they are however much longer so when the time comes for fitting them I’ll have to extend the holes outwards to accomodate them (hence why the position of the control knob holes is perfect for me). This cutting will chop out the existing screw holes that hold my temporary pickups in place, so that will have to come later.

Deciding on components and wiring

The original Jazzmaster wiring requires two 1MΩ pots: one linear and one audio (log) taper, for volume and tone respectively. Strats and Teles have 250k pots while humbucker-fitted instruments like Gibsons have 500k; higher value pots add brightness while lower values ones make the tone darker. I believe Gibsons use 500k pots on their volume and tone controls to offset the punchier sound of humbucking pickups, while Strats and Teles can already get a lot of treble from single coils so use 250s to reduce brightness. Jazzmasters use 1M though, which must make their tone even brighter still! The pots that were originally fitted to this guitar were, surprisingly, 500k and not 250k; I reckon this was to get a brighter sound out of the weak Squier pickups.

Apart from these I needed a set of three Strat-style control knobs, two lengths of metre-long hook-up wire in two colours (for live and ground), a 0.02μF capacitor for the tone control (one of the more expensive ‘orange drop’ types…it’s only a few pence but they’re supposed to be better quality than ceramic) and a three-way blade switch. Fortunately my father is a trained electrician so has a spare soldering iron that I’m able to borrow.

The only components on my list that Axetec don’t supply are those 1M pots, so I fired off an e-mail to DiMarzio to see if they stocked them. Again, that’s a more expensive option than the 250 and 500k pieces from some online places but when we’re talking only a few pounds (£6.50 in this case, minus VAT and postage) for a really smooth and reliable component, I think the extra outlay is worth it. The UK DiMarzio office were extremely helpful and offered the 1M pots that have “…a custom taper (closer to audio than linear) which we find to be good for both vol & tone.” according the e-mail reply. It’s a bit of a compromise on the taper, but a pretty good once considering how hard they are to find and might wind up sounding better anyway.

Running total

• Scratchplate: £12.00 (€15.35)
• Scratchplate screws (set of 11): £1.60 (€2.03)
• Sprague Orange Drop Capacitor (0.02μF): £1.45 (€1.86)
• 3-way switch, plus tip: £5.35 (€6.84)
• Hook-up wire, 2m: £3.95 (€5.05)
• Three Strat-style knobs: £2.00 (€2.56)
• Two 1M potentiometers: £15.20 (€22.12)
• Replacement bridge: £33.94 (€43.41)

Total so far: £75.49 (€94.88) excluding P&P