This modification is a permanent one, made to the guitar’s neck humbucker rout (and, if needed, a wall within the rear control cavity). Though I'm aware there are various techs throughout the globe who will perform this work, I have no firsthand experience in dealing with them (I know VJ can vouch for Patrick Cummings at iGuitarWorkshop, New York). Alan Hoover, inventor and seller of the Sustainiac, has not only stopped offering Fly installations, but will actively discourage Fly owners from even attempting the project (he will nonetheless sell you a standard humbucker-size driver kit requiring modification to the pickup and the guitar).
Tools/equipment needed:
For removing stock neck pickup and threaded inserts/bosses
3/32 Allen/hex wrench for 10-32 x 5/8" Dimarzio hex pole piece screws
Spare 10-32 x 5/8" screw
Pliers for working the threaded bosses out of the neck pickup rout
For Sustainiac installation
Soldering iron (and associated tools and supplies)
Tin snips/metal shears OR dremel with cutting wheel (for trimming driver baseplate)
Double-sided mounting adhesive (for mounting Sustainiac driver)
For routing
Electric drill OR drill press OR tabletop router OR dremel with router bit
35mm Forstner bit (if using drill)
Chisel (if not using dremel)
ShopVac or other vacuum cleaner, and a work rag (for removing chips and dust as you work)
Modified Sustainiac Pickup/Driver (for regular test-fitting)
Optional tools and supplies
ruler, calipers, Fly pickup routing template, sanding barrel for dremel, tape, plastic, and/or cloth for covering face and neck of guitar around routing area. The option of paying someone else to do the work for you from the start is preferable to paying someone to look at what a mess you've made after the fact.
…
1. Modify Sustainiac driver
Using either metal shears/tin snips or a dremel with cutting wheel, trim the mounting tabs and lightly radius the corners of the driver baseplate. Take care not to bend or warp the baseplate (though it is much sturdier than most pickup baseplates, the entire driver assembly is merely epoxied together).
Pictured below is the unmodified driver baseplate next to a Fly pickup (top and bottom, and from the side), followed by the trimmed driver baseplate.
Pictured below is the trimmed driver fitting into the Fly pickup rout. Note how much taller than the stock Fly pickup the driver is. This height difference is our measurement for how much deeper the pickup cavity will need to be routed.
2. Remove stock neck pickup and threaded inserts/bosses
Unsolder or clip the neck pickup’s five wires from within control cavity (the components they’re soldered to will differ between production eras, which is a topic covered elsewhere on this site). With the guitar’s strings slackened or removed, use the hex wrench to unscrew the neck pickup’s mounting hex pole pieces (under A string for neck-facing coil, under B string for bridge-facing coil). If the pickup’s wires were disconnected previously, the pickup will be able to lift out and be removed from guitar. Make sure the foam spacer and any other remaining debris is removed from the pickup cavity rout.
Use the hex wrench to fully thread a screw into the threaded inserts/bosses embedded in the pickup rout. These bosses are permanent installations; meaning we can expect some tear-out from the wood when removing them.
Forum member @Augustonian found that heating the screw/bosses with a soldering iron allowed them to pull out of the body with minimal tear-out:
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For those electing to not hear the bosses/inserts beforehand: If you use a chisel, dremel, or drill bit to chip away at the wood surrounding the bosses so that they’re loose enough to be worked out of the guitar with a pair of pliers grabbing the attached screw and wiggling it free, you'll minimize unnecessary tear-out. You can simply work the pliers side to side to loosen the bosses from their mounting holes. Be aware that, if insufficient wood has been removed from around the bosses, the screw will bear all the metal fatigue from being worked side to side with the pliers and break off, making the extraction more difficult. Basically: Treat the extraction of the threaded bosses like you're pulling teeth; with no more force than necessary.
Pictured below is the neck pickup rout with the wood surrounding one boss removed for illustration, as well as the results of removing both bosses (note how much wood was removed to allow them to be worked out without cracking the surrounding wood):
3. Deepen neck pickup rout
On paper, the power tool you choose to deepen the rout will make this either a slow or fast job. In reality, you need to pace yourself in making shallow passes, while regularly clearing debris and test-fitting the Sustainiac driver until you’ve achieved your desired height (approx. 3/16"/4.7mm space between top of pickup and bottom of string, as recommended by Alan).
Note that the holes showing the installed depth of the threaded inserts/bosses you removed is likely less than the added depth the driver will need to fit. This means that, so long as you’re regularly clearing debris from the rout, you can use the mounting holes for the bosses as a visual depth guide to how much more wood you can get away with removing.
For this guide, I routed two Fly neck pickup cavities deeper, using two different methods:
With one, I did the bulk of the wood removal with a 35mm forstner bit in a handheld cordless drill. Alan Hoover used a forstner bit in a press for his Fly installations. I haven’t owned a drill press since 2015; when I stopped working on guitars professionally and moved cross-country. The only reason I used a 35mm diameter bit was because it was the largest I had on-hand, and happened to be close enough for this job. For the corners and other areas of the rout that the bit didn’t clear, I chiseled just enough to prove it could be done, then finished the job with a dremel sanding barrel.
With the other guitar, I considered making a template and using either a tabletop router or dremel in a plunge-router jig, before deciding that a freehand dremel with a router bit would be fine; so long as I took my time in making shallow passes and regularly stopping to clear debris and test-fit the driver. And because I never went deeper than the bottom of the mounting holes drilled for the bosses in either guitar, at no point was I fearful of breaking through the rear of the instrument.
Pictured below is one of the guitars with its deepened neck pickup cavity rout on display, followed by photos of the driver sitting in the now sufficiently deepened rout:
4. Incorporating Sustainiac into pre-existing guitar circuit(s)
Any time you're installing new guitar circuitry in parallel with what's already onboard (such as adding a piezo, 13 pin, or other modular preamp system), you avoid troubleshooting down the line by first ensuring that the essential components you're integrating with are all functioning as they should. In the case of the Sustainiac, this means removing all components from the guitar’s control cavity with the exception of the bridge pickup (and middle, if you have an S2 or 824 you're modifying), the pickup selector switch, the volume and tone pots, and the output jack. If your basic, passive electromagnet guitar circuit components are working as they should, then you can expect the Sustainiac preamp integration to proceed with minimal fuss.
So now comes the ingenuity of figuring out how to fit the Sustainiac board, bridge pickup and driver wires, battery, and switching components being utilized for on/off and harmonic mode switching to the control cavity: You may find you need to englarge the cavity by carving space out of a cavity wall with a dremel sanding barrel or a router bit.
Here is a link to Hoover's diagram showing the routing he generally did along the Fly rear control cavity wall adjacent to the flatspring cavity. I ended up doing the same for my Flys, and mounted the plastic-insulated Sustainiac preamp board along that cavity wall with the same double-sided tape I mounted the driver with.
Now, the actual diagram for integration of the Sustainiac circuit into your Fly circuit is case-dependent and; so, won't be included, here - But I'm happy to draw one up for anyone who asks (It's just connecting a few new wires to whatever your pre-existing guitar components are, after all). So what I'll do as a compromise is to attach some illustrations isolating the many intimidating tentacles of the Sustainiac board by function (click each image to enlarge):
The pickup (or "signal") wires, isolated in the next diagram below these three paragraphs, consist of the following: On the 8 pin connector side of the preamp, you have a white wire which is soldered to the same solder point as your bridge pickup "hot" wire on the pickup selector switch. In a two pickup guitar (Which most Flys are), the blue wire on the 8 pin side is connected to the blue wire on the 10 pin side after both are shortened (all pickup signal-carrying wires in the Sustainiac circuit should ideally be kept to a minimum length and ziptied or otherwise retained away from the driver signal-carrying wires such as the brown 10 pin wire and gray/violet pair from the 8 pin side which activate harmonic feedback).
In the case of a three pickup guitar, the 10 pin blue wire carries the neck pickup preamp signal and; so, should be soldered to the neck pickup contact on the pickup selector switch; with the 8 pin blue wire soldered to wherever on the selector switch is common to both the neck and middle pickup signals (again: case-dependant wiring). However, in a two pickup installation, the two blue wires are joined, and the orange wire from the 8 pin side carries the neck pickup signal to be soldered to the neck pickup input on the selector switch. In a three pickup installation, the orange wire is soldered to the same contact of the selector switch as the output wire going to the input of the volume pot.
On the 10 pin connector side, we have three wires which the Sustainiac Driver pickup's two hot wires get connected with: The gray wire is soldered to the pickup's red wire, and the pickup's black wire is soldered to a double pole switch which connects it to either the orange 10 pin wire (the input to the neck pickup preamp), or to the feedback amplifier via the brown 10 pin wire. That brown wire can be used in another way called "harmonic mix mode" (described in greater detail by Alan on his site). The function of the 10 pin blue wire has been described above. Depending on the polarity of the bridge pickup feeding the sustainer system, the Sustainiac pickup's red and black hot wires may need to have their connections swapped (just as you would if one of your pickups was out of phase with the other).
The "option" wires are as follows: The gray/violet pair on the 8 pin side should be twisted together and isolated from other signal-carrying wires, then soldered to an appropriate single-throw switch to toggle on harmonic feedback when they're connected. The 8 pin yellow wire goes to the input of an optional feedback gain pot, and is clipped and isolated with no connection in all other applications. On the 10 pin side is a violet wire which shunts the neck pickup signal through a mild low-pass filter via a capacitor in parallel. It's a subtle revoicing effect. The white wire next to it engages a flat neck pickup signal boost when connected to ground.
Lastly, we have the "power" wires: The black wires both go to ground - But the 10 pin black wire should ideally be soldered to the same grounding point as the battery (-) wire. The red wire connects to the (+) battery wire. The final two wires activate each of the two active circuits: If the green wire is soldered to a common grounding point, then the Sustainiac neck pickup preamp will power on when you plug a cable in to the guitar's output jack. Alternatively, you can rout this path to ground through a single throw connection so that the battery won't drain while the cable's plugged in. The yellow wire disables the pickup preamp and activates the sustainer/feedback circuit when grounded via a single throw connection.
In both of my installations, everything worked once I had soldered the final wire. In any case, you should be certain everything in the integrated Sustainiac circuit is 100% working as it should before you integrate a piezo or 13 pin preamp circuit which the Sustainer/mag circuit will have to pass through.
Lastly, I can assure you that the results will indeed resemble a nightmare of a spaghetti factory (someone has since informed me that it's reminiscent of "what happens when you open the door to an electrician's closet"
):But a few zip ties and some masking tape in the right places can fit it all under the cavity cover:
#DIYGuides #PickupPreferences
