I want to wire up my custom Fender USA Jaguar using a “Johnny Marr” circuit. I’ve had a set of Creamery “Alt-88, Mid-range” pickups wound with this job specifically in mind, and although the usual Fender Johnny Marr specification calls for custom wound Bareknuckle pickups – I think the alternative stylings of these Creamery pickups is well worth a try with the JM circuit. The wiring is based on a standard Jaguar, but is somewhat different and has a few major functional differences – especially in the switching. The usual, three switch selector plate is replaced with a single 4-way blade switch. This provides more Telecaster-like switching options – offering individual pickup selections, as well as combined options in both parallel and series. Since the pickups are RW/RP – the two pickups together in series, effectively act as one large humbucker and offer a more modern take on the Jaguar’s characteristic, single coil sound.
The other main difference with the JM circuit, is the fact that the usual, split rhythm/lead volume and tone switching functionality is completely removed. Instead, there’s a single master tone control, alongside a single master volume control on the main control plate. The upper rhythm plate is preserved, but it’s function changes to allow for two filters which relocate the classic “strangle switch” function – normally found alongside the pickup selector switches on the lower plate. The first, (vertical), switch filter replicates the original filter, and will cut a good deal of lower and mid-range frequencies from the signal, across all selector positions. The second, (horizontal), switch filter is wired so that it only comes into play when the switch is in position 4, and has the bridge and neck pickups connected in series. This sharpens up the characteristically darker sound, produced by the paired pickups.
Unlike some other Fender guitars, such as the Stratocaster or Jazzmaster, the pickups and circuitry are all mounted onto and into the actual body of the guitar – rather than having some, or all, of the elements mounted on the scratchplate. This makes the actual wiring of the guitar a little more complicated than it probably ought to be, and there are certain conduits located in the body which will need to allow for up to six wires to pass unhindered. In places – there’s a real “spaghetti junction” of wires running here and there. The last time I wired a Jaguar, I was totally inexperienced with the whole thing and chose a pre-wired harness to “drop-in”. This time, I have a circuit diagram printed out, and I need to work out which way round to approach things. Having gained experience on other, perhaps simpler circuits – the best approach would seem to be to wire the outlying “rhythm” and main control plates first, before bringing everything together at the switch plate. The pickups will wire-in last, and then the scratchplate can be finally fitted over the top. That’s the theory – now let’s see if that wiring diagram is up to scratch.
“Johnny Marr” circuit wiring – Rhythm plate
The wiring diagram I’ve obtained was found online and graphically, it certainly looks like a copy of an authentic Fender diagram. At first look – it’s a familiarly complex Jaguar layout – but there appear to be a few wierd inclusions, (what does that 56K resistor actually do??). I’ll follow it all faithfully, including the colour coding, and see where that gets me. The first task is to assemble the upper, filter plate components. For that, I’ll be using:
2 x Switchcraft, 2-position (on/off), slide switches
2 x 0.003µF ceramic disc capacitors (Fender parts number 005-4509-049)
Short length of tinned copper jumper wire
4 x lengths of coloured, “Gavitt-style”, cloth covered “push-back” wire. Red, orange, yellow and red
all fitted to the previously installed:
Fender, “Johnny Marr” Jaguar, Dual Switch Preset Control Plate, (Fender parts number 009-1893-000)
The switches are first checked for quality, (some just don’t feel positive enough in their action), and are attached to the control plate with some replacement, recessed, stainless screws from Charles Guitars. The lengths of coloured wire are roughly measured against the body conduits, allowing for a little extra wastage in case of routing difficulties. After checking the correct orientation of the plate – all of the required switch terminals are then pre-tinned, using a little solder.
The top, vertical switch only requires two of the usual six terminals to be operational, and I happen to have a variant of the switch, which only has just these two terminals built in. Wiring the switch couldn’t be simpler. One of the 0.003µF capacitors is prepared by trimming and folding the legs into a suitable position with a pair of needle nosed pliers. By bending the legs over to form small hooks and then pushing them into the small holes on each terminal – the capacitor can be positioned above the switch housing, and left in position whilst the cores of the blue and orange coloured wires are pushed into the correct terminal holes from the other side. The connections can then be made by flowing a little solder around each terminal – ensuring that the soldered connections look bright, and appear to fully envelop the wires on each side of the connection. A final check can be made by connecting the loose ends of each wire to the terminals of a multimeter, and then checking for continuity, and the operation of the on/off switch function.
The lower, horizontal switch is a little more complicated, and involves all of the usual six terminals to be present. A jumper wire is fashioned first, using a short offcut of tinned copper wire. The ends can be hooked through the holes in the first pair of terminals, using a pair of needle-nosed pliers to keep the work as neat as possible, and then the solder joints can be made.
On this switch – a 0.003µF capacitor sits across the third pair of terminals and once again, the legs of the cap are trimmed and shaped so that the capacitor sits neatly above the switch housing. Once it’s position is finalised – the solder joints are made. Finally, the red and yellow coloured wires are soldered onto the middle pair of terminals – as indicated on the wiring diagram.
The plate can now be fitted into position on the guitar. A lugged grounding wire has already been prepared. This is securely looped around one of the switch screws and is sandwiched between the switch housing and the metallic underside of the cover plate. I’ll eventually firm up all of the switch screw connections with a little dab of Loctite – but for now, I’ll leave them hand-tightened, in case I need to make any later adjustments.
With the cover plate grounded, I gather up the ends of the four coloured wires, loop them around the switches and cavity so that they fall in a natural sort of curve, without kinks, and then thread the wires through the interconnecting conduit towards their individual destinations. The wires are routed alongside where the neck pickup will sit, once it’s in place, and will have to run on one side of the neoprene spring, so that they aren’t eventually trapped by the pickup, orfouled by the pickup adjustment screws. Finally, with the wires roughly in place, the control plate can be loosely secured again.
“Johnny Marr” circuit wiring – Main control plate
The main control plate has more of a familiar sort of look about it. (Except, of course for that CC resistor. It’s almost like half of a treble bleed circuit. Is it some kind of low-pass tone filter?). I normally prefer a central “star” grounding layout on my builds, but since I’m following a distinct Fender schematic, I’ll stick to that. This means that the grounding arrangements for this part of the circuit can be much more straightforward, but I’ll come to that… For this section of the circuit, I’ll be using:
2 x CTS 1.0M Audio pots
1 x “K40Y-9”, Vintage “Soviet surplus” 0.01µF PIO capacitor
1 x 56K Carbon composite resistor
1 x Switchcraft jack socket
“Gavitt-style”, cloth covered “push-back” wire. Black and White
all fitted to a previously installed:
Fender “American Vintage”, Jaguar Master Control Plate, (Fender parts number 005-4505-000)
The pots and jack socket have only been temporarily fitted thus far – so a dab of Loctite to the nut of each, helps secure them more permanently in place. The pots are oriented so their terminals face each other, and the jack checked so that it’s positioning doesn’t risk fouling anything, or potentially shorting out against the sides of the main control chamber. This is a relatively simple layout to solder – there are only two wires which attach to this part of the circuit from elsewhere, and so all but one of the connections can be permanently fixed at this stage.
It seems to make sense to start with the jack. A length of black cloth covered wire is prepared for the ground connection, and soldered into the “ring” terminal of the socket. Since this wire will be connected, at the other end, to the grounded brass plate at the bottom of the main control cavity, it will have to be long enough to allow the plate to be removed, and should ideally flex gently as the surplus is looped around. A bit of reinforcement at the plug end is usually a good idea, so a short length of shrink tubing is applied over the completed solder joint. The white, “hot” wire is laid to directly connect the “tip” terminal of the jack socket with the middle “wiper” tab of the volume pot. The wire is trimmed to the ideal length, and routed underneath and around the main body of the tone pot, so that it’s out of the way. It’s then soldered into place.
The output terminal of the volume pot is connected to ground, and the easiest way to achieve this, is to bend the terminal back against the back of the pot itself – adding a good dollop of solder to make sure the connection is permanent.
Moving on to the tone pot – the 56K CC resistor sits neatly in position once the legs have been bent into a suitable shape, with a pair of needle-nosed pliers. I leave one of the legs a little long for now – since the input terminal won’t be soldered just yet, and the extra length helps brace the resistor in position whilst the other, (middle, wiper), terminal is prepared and soldered up. There, a short black wire is also prepared to join the tone pot to the input terminal of the volume pot. This short wire is cut to size and inserted into place, with the other end sharing the tone pot’s middle, “wiper” terminal opening with the trimmed leg of the resistor. Two dollops of solder, and the wire is secured.
The 0.01µF, vintage “K40Y-9” capacitor is similarly prepared by bending the wire legs into shape, and trimming off any excess. I can’t see any real need to insulate the leads at all – so long as the cap is laid neatly, and out of the way, over the back of the tone pot. There’s plenty of room in the control rout, and it’s doubtful things will get congested in there. One side of the capacitor is connected to the output lug of the tone pot, with the other side grounded onto the metal housing at the back of the pot. (A possible future refinement of the circuit might involve linking the backs of both volume and tone pots together, and from there running on to a common ground, or at least down to the brass shielding plate at the bottom of the control cavity, where all the other ground wires seem to end up. However – since I’m following the Fender schematic as much to learn about how the circuit works, as to figure how best to shield and ground the thing – I may as well stay true to the original design, for now).
With the main control plate now “made up”, I can connect it into the circuit, and fix down the cover. The grounding of the cover plate has already been achieved by the addition of a copper tab around the rear fixing screw. This links the cover plate to the copper foil lining and thus, by direct contact at the glazing bead fixings, to the brass shielding plate at the bottom of the cavity. The plate is inverted at a convenient location adjacent to it’s final position. The bodywork is protected from damage with a suitable cloth, and then the black ground wire from the jack socket is soldered directly onto the brass ground plate at a location where it won’t foul or snag any of the plate-bound components. (None of them really go that deep anyway). The blue wire from the upper filter plate is routed around the main wire run between the two pickups, through the conduit hole, and into the main control cavity. There, it’s trimmed to a suitable length, leaving a little excess for manoeuvrability, and then connected into the input terminal of the tone pot, alongside the as-yet unsoldered leg of the 56K resistor. The connection is secured with solder, and the excess length of the resistor leg is trimmed away.
The plate can now be inverted and temporarily secured into place with its’ three fixing screws. Again, the excess lengths of wire are carefully routed around the pots, so that they tend to fall naturally, and there aren’t any kinks or compressions.
“Johnny Marr” circuit wiring – 4-way selector switch plate
The switch plate is the most complicated of the lot, and there will undoubtedly be a few issues unless I try to route the wires logically, and keep the runs to a reasonable minimum. The Fender schematic is colour coded, and I’ve found it useful to reproduce the colours exactly. This not only helps get the right wire to the right place – it also serves to begin to get a bead on understanding how the circuit functions. From the schematic, I can deduce the switch functions without the need to check on the Fender specs – although it will be good to double check later, once the work is done, to help identify any possible discrepancies in my replication of the circuit wiring.
The 4-way switching is intended to provide:
Position 1 (towards the rear): Bridge pickup only
Position 2: Bridge and neck pickup, in parallel
Position 3: Neck pickup only
Position 4 (towards the headstock): Bridge and neck in series
I’ll be using:
1 x Oak Grigsby 4-way blade switch
“Gavitt-style”, cloth covered “push-back” wire. Black and Green
all fitted to the previously installed:
Fender, “American Pro”, Jaguar Lever Switch Control Plate, (Fender parts number 009-1903-000)
The switch, of course, takes care of the main pickup selection functionality of the circuit. As such, it is directly connected to just about every other operational part of the circuit. Not only do the three remaining coloured wires from the upper filter circuit connect in here – but so will three of the four pickup wires, once the pickups are plumbed-in. Add in a few extra jumper wires and there’s a real potential for a nasty tangle, as all the wires squeeze into the tight cavity, running alongside and around the blade and terminals of the switch itself. Consequently, I’m following the Fender schematic faithfully, and trying to establish tidy and economical routings for all of the wires. I’ll aim to connect the switch to the rest of the previously installed components first, and then connect the pickups as a second, separate exercise.
The switch is oriented on the plate exactly as on the diagram – with the terminals off to the right hand side, once the plate is inverted. There are two jumper wires indicated on the diagram, both linking the second and third terminals on each side of the switch blade. On the right hand side, a short black wire is prepared joining the terminals – however this won’t be soldered into place just yet. Instead, the ends of the wire are hooked over, and the wire is left hanging. The wire is cut to a length which allows it to be looped down alongside the switch blade, where it won’t take up so much room and add to the inevitable congestion.
On the left hand side, a similar green wire is laid. Here, provision is made to add an extra jumper wire which will eventually join onto the previously installed, lugged, cover plate grounding wire. These wires can be soldered into place on the switch straight away. The additional length of wire needs to be long enough to allow for the plate to be inverted, and positioned conveniently whilst the rest of the wires are soldered-in. I leave it a little longer than absolutely needed for now, so I can assess the best way to position the plate for the next set of connections.
The plate is positioned upside down, where it can be inverted without twisting any of the wires too much. If I install the lugged grounding lead to the “rear” switch screw, I can keep that lead on the “inside” of the switch when the plate is fitted, away from most of the rest of the connections. If I then route all of the other connections around the “front” of the switch body – once I invert it again, I should be able to provide a little extra length for manouevre, and still keep the wires from kinking when the plate is reversed.
With the ground lead in place, and the lug positioned between the switch housing and the cover plate – there’s just enough room to connect the loose end of the green jumper wire to the remainder of the exposed grounding tab. The green wire is then trimmed to length, so that the jumper runs neatly, and economically, down the side of the switch, and. the connection is soldered
The three remaining coloured wires, (yellow, red and orange), from the upper filter plate are then routed through into the switch chamber, around the switch, and connected to the switch terminals as shown on the circuit diagram. The orange wire shares a terminal with the, as-yet unsoldered, end of the black jumper wire. After trimming all of the wires to length – each connection is secured with a blob of solder.
The pickups I’ve had made for this project are Creamery “Alt-88, Mid Range” Jaguar pickups. I had these made earlier in the year, but haven’t had a chance to wire them up yet – due to my ongoing eye problems. It will be good to finally get a chance to hear them! The pickups are a slightly overwound variant of the traditional vintage, AlNiCo 2 Jaguar single coils, and Jaime, at the Creamery, provides a slightly more up-to-date alternative with “a little more bite and attack”. I’ve opted for warmer sounding AlNiCo 2 poles instead of the taller, slightly brighter sounding AlNiCo 5 alternatives, and also chosen a “Mid Range” focused winding instead of the more “Treble” focused option. I’m hoping the updated specifications will suit the “Johnny Marr” switching circuit well. Creamery pickups come highly recommended, and I’m currently waiting for Jaime’s order books to open again, so that I can get some wound for both my Jazzmaster and JagStang builds.
The pickups are already wax potted, with chromed claws fitted. I really like the look of traditional string binding on single coil pickups, and I’m intrigued to see how a set of Jaguar pickups will look on the guitar without the usual cream or white, plastic covers. These pickups are therefore potted with white string coverings only. Jaime offers a red string option for some of his more “alternative” pickups – but not, apparently, for these. Maybe I should have asked for a one-off, custom job..? The way this all red Jag is turning out – a little red string showing might have been a cool idea. No worries – I like the look of these, with all of the “guts” showing.
The neck pickup drops into place on top of the neoprene spring, and I can secure it down with two of the four fixing screws provided. I always get nervous when screwing down Jag pickups – it almost seems impossible that the screws can be so long without appearing out of the back of the guitar as they’re tightened down. I adjust the level until the pickup poles are sitting just about in line with the fingerboard. I’ve routed the ground wires, (a black cloth covered wire twisted together with a thin, red plastic covered wire), to run below the pickup – on the other side, away from the coloured wires which run from the upper filter plate. The red plastic wire is partially unwound from the black wire, and routed on down towards the main control cavity, and the two cloth covered wires are threaded through the conduit hole, and into the switch cavity. There, I direct the wires around the switch alongside the other coloured wires, and then secure them to the relevant terminals with solder, according to the schematic. (The white “hot” wire connects to the same terminal as the yet-unsoldered end of the black jumper wire). Rather than trim the pickup leads down – I opt to draw some of the excess length back into the central wire run and loop it around, out of the way. It shouldn’t cause any problems there, since the cavity is fully shielded.
The bridge pickup is fitted into place next. The white “hot” wire is routed towards the switch. The ground wires will run through the conduit into the main control rout. The “hot” wire makes the final connection at the switch, with excess length, again, drawn back and looped around in the central wire run. The switch plate can then be inverted, and everything positioned so that the plate can be attached to the body without kinking any of the wires, or stressing any of the soldered connections too much. It’s temporarily fixed in place using the two assigned screws.
The two fine red wires from the pickups are wires which directly ground the metal claws. These are an integral part of the pickup assembly, and the ground connections need to be made to get the pickups to function correctly. The neck claw ground is just long enough to reach a point in the central wire cavity, just about alongside the end of the bridge pickup. Here it can be attached to the brass base plate with a drop of solder. Since all of the brass plates are, themselves, grounded and contiguous – I could just about attach that wire anywhere – just as long as it’s directly connected to ground. It’s just that it’s convenient where it ended up.
The bridge claw ground (red, plastic covered), and the bridge pickup ground, (black, cloth-covered), wires are both run into the main control cavity. There, the red claw ground finds a home with a soldered connection, direct to the brass base plate. The black “ground” pickup wire loops around, and is connected to the back of the volume pot. That’s the pickups connected.
With all of the plates temporarily screwed down into place again – I can check the functionality of the circuit by gently tapping the pickup poles with the metal blade of a screwdriver. This Fender “Mustang Micro” headphone amp is ideal for such a job. Not only is it wireless – meaning I don’t have to plug in to an amp, and wait for any valves to warm up first – this little pocket wonder also gives me a choice of modelled amps and effects settings, to hear the familiar “clunk” of a properly-connected pickup through.
I can check the pickup operation and switching – even the nominal filter, volume and tone functions – all by tapping the pickups with the switch in the four different positions. There’s no buzzing or noticeable distortion with any of the “clunks”, and the pickups switch in and out according to plan. Looks like the circuit is good to go. The last check is to ensure all of the Jaguars’ various metal plates and parts are grounded. Anything left ungrounded risks creating an annoying hum or buzz when a particular metal part is touched. It’s the usual run-over with a multimeter – checking all of the metal components for continuity to the ground. Copper lining, brass plates, cover plates, claws, tremolo, bridge…
Ah – I’ve clearly forgotten something.
Since I’m not using a central “star” grounding point – I’ve not yet actually got around to providing a solution as to how to ground the bridge. (Other than, perhaps, letting the strings themselves do the job, but I’m always a belt and braces sort of guy). The guitar body was purchased with some hardware already fitted – so the tremolo plate already had an obvious solution in place. The bridge, however, was left unresolved, and I’d like to work out a more definite ground connection.
The normal way to ground the Jaguar bridge is usually via one of the two support “thimbles”, and there’s sometimes a special conduit located, through which a wire can be directly threaded through into the thimble hole. However – the thimbles are already pre-installed here, and I can’t see any such conduit drilled on this body. I’ll have to improvise…
The most logical approach seems to be to run a grounding wire up from the brass grounding plate under the bridge pickup, and then across the short distance to the nearby thimble where it will be concealed by the scratchplate. Ideally – a proper connection with the thimble is usually made by running the wire into the thimble hole, whilst the thimble is pushed down on top. However – for that, I’ll have to remove the thimble first, and that involves a certain amount of risk. I really don’t want to damage the factory finish – but I really need a good connection for any properly functioning ground to the bridge thimbles. I might have to grit my teeth and go for it…
Pulling a thimble is relatively easy, if you take your time and also protect the body sufficiently. The secret with a thimble on a nitro lacquered body like this, is to gently warm the thimble first with a soldering iron. 15 or 20 seconds, with the tip slowly run around the inside lip of the thimble warms the metal up, and softens the lacquer enough to break any adhesive grip it has. Once the thimble is warm, and with the body work protected as appropriate, you can then try and pry up the edge of the thimble, or you might try and grab the lip with a suitable pair of pliers, and gently pull. I was able to protect the body with the thin metal of an old fret shield, and then pull the thimble straight out with a pair of flat ended pliers. The thimble is cleaned off while it’s still warm, and the thimble hole is cleaned out with a 3/8″ reamer.
The ground wire can then be prepared, and soldered/fixed into place. I’m using a multi-core wire, so I can separate out all of the threads at various places, and maximise any metal to metal contact. The wire is anchored to the brass shield plate at one end, and then secured against the side of the pickup cavity with a few strips of conductive copper foil. The wire runs on, out over the face of the body, and the splayed out ends finally drop into the full length of the thimble hole. The thimble is pushed back into place – securing the wires, and providing a good, enduring connection. The remaining exposed wire running across the body of the guitar will be hidden under the scratchplate. I cover and secure that with a few extra strips of copper foil, and then place a piece on the underside of the pickguard which mirrors the location. This extra piece on the reverse of the scratchplate joins onto the existing shielding there, and will provide yet another point of contact once the plate is screwed down firmly.
This wire should now ground both of the thimbles via the bridge, which itself has metal support posts which are in direct contact with the base of each thimble. The only remaining metal part which isn’t now directly grounded, is the mute plate – and that isn’t currently installed, having been removed to allow the scratchplate to be removed, and to access the thimbles. Once installed – it is possible that it will sit in contact with the bridge posts, but that might well change in operation, or over time, as any such direct metal-to-metal contact slowly wears. The best way to check, is by continuing grounding and continuity checks with a multimeter once everything is re-assembled. Of course – any sudden buzz when touching the mute plate when playing, would also be a dead giveaway. If the plate should need additional grounding, a separate wire will have to be laid which directly contacts one of the mute plate fixing screws. This could easily be accommodated alongside the bridge grounding wire, and would remain hidden by the scratchplate – but it seems to be a typical feature of wiring a Jaguar, that the cover plates, mute and bridge tend to be on and off more than a few times, before the build is finally finished.
So – for now – the scratchplate is reinstalled, and the cover plates are fully tightened down once again. With the scratchplate fitted – the mute plate is reinstalled, and adjusted until it operates properly. The bridge is dropped into place, and the clearance above the mute plate checked, so as to avoid the bridge riding on the mute plate fixing screws.
A grounding continuity check with the multimeter, shows that the mute plate must, currently, be in contact with the bridge – since continuity is demonstrated with all other grounded parts. This appears to be maintained even when flipping the mute up and down – so, for now at least, I’ll hold off on installing any other grounding, and see how everything behaves once the guitar is strung and set up.
I slide a black Fender “Original Vintage” Telecaster blade switch tip, (Fender parts number 009-3602-049) into place, and fit two Fender “American Vintage ’65” knobs, (Fender parts number 001-9455-049), onto the pot shafts, on the control plate. The switch tip works fine. I did originally have an issue with another non-Fender switch tip, which fouled the switch screws at either end of the blade, and made selecting positions 1 and 4 a little less positive than they should have been. The, (somewhat more expensive – it has to be said), Fender part fits much better, and the switch is allowed to travel the full distance in either direction. I suppose you get what you pay for…
However – I must also say – that having bought in a few sets of Fender “American Vintage ’65” knobs, for my various, current offset builds – I really probably should have opted for some of the Kluson-made alternatives, which I used on my Olympic White Jag. The 1.0M CTS pots only seem to be available with a split shaft – yet “vintage type” Jaguar control knobs are designed to be fitted by tightening a small grub screw against a solid shaft. That normally isn’t a problem – a thin brass barrel sleeve can be slipped over the pot shaft, and the grub screw tightened against that. However – I don’t know if the problem lies in a slight metric/imperial discrepancy – but I just can’t get a hex spanner to fit the tiny grub screw tightly enough, to avoid slipping and potentially stripping the screw tip, or the grub thread itself. (The Kluson alternatives have a larger, slotted, brass screw assembly). After a fair bit of huffing and heaving, I find the best way to fit the knobs is to tighten the screw with the knob off the guitar, and with the thin brass barrel inside – tightening the nut until the sleeve is visibly distorted on one side. Then, the knob and barrel together, are pushed down over the split shaft – so that the two blades of the split are slightly flexed together. It’s a matter of trial and error to find the “sweet spot”, which allows the knobs to sit firm without distorting the split shaft too much – but eventually the knobs are fitted reasonably satisfactorily. However – I have a feeling these will bug me over time – and I’ll probably swap them out for Kluson alternatives at some point in the future.