The “Dead Spec” Silver Sky, created by PRS for John Mayer’s work filling Jerry Garcia’s shoes with Dead & Company, is a fitting tribute to the Grateful Dead frontman’s famed Fender Stratocaster.
Hello and welcome back to Mod Garage. This month, we will have a look at the new PRS John Mayer “Dead Spec” Silver Sky guitar, what’s so special about it, and how close you can get to it with your good old Stratocaster. So, let’s check it out.
Without stepping on anybody’s toes, I think we can say that the Silver Sky is PRS’s own modern interpretation of the Fender Stratocaster without being a simple and shameless copy. The John Mayer “Dead Spec” model was designed for the guitarist to use with Dead & Company, and it has several alterations that are a tribute to Jerry Garcia’s own Strat, Alligator. The “Dead Spec” was released last November and had a limited production run of 1,000 guitars. So your chances to grab one are really limited, and the guitar is not cheap.
So, what’s inside this guitar and how close can we get with a standard Stratocaster without breaking the bank?
Let’s start with the physical specs, which are somewhat special compared to a standard Stratocaster. In general, the body is made from lightweight swamp ash, and the bolt-on neck is maple with a rosewood fretboard, 22 frets, and a traditional 7.25" radius. Nothing special so far.
Bridge/tremolo construction: The “Dead Spec” has a very special kind of hardtail construction that I’ve never seen before. The tremolo is fitted into the body without springs, and the routing is super tight so the tremolo block can’t move. Next to it is the battery compartment (more about this in a minute).
Photo courtesy of PRS Guitars
If you want to get as close as possible, a hardtail Strat is one option. This is virtually the same but without the tremolo block. If you have a standard Strat tremolo, you can use a wooden block to convert it to hardtail specs.
Bridge/tremolo material: PRS decided to use their own Gen III tremolo—their version of a Strat trem—with a brass inertia bar/tremolo block as a surface-mounted bridge. It should be no problem to find a new brass replacement for your Strat’s tremolo. The brass bar will change the primary tone of the guitar (when playing it without an amp), but how much of this will be audible in the amplified tone depends a lot on the individual guitar. If you want to get as close as possible, a brass bar will be the way to go.
Brass nut: This was very popular in the ’70s and early ’80s, and Garcia’s Alligator indeed had a brass nut. It should be no problem to find a brass nut for your Strat, or at least a brass blank to make one. I would like to second what I said a minute ago: A brass nut will change the primary tone of your guitar without any doubts. How much of this will be present in the electrified tone depends on the certain guitar. So, leaving your stock nut in place is always an option.
String retainer bar: PRS decided to add a “cowboy-style” string retainer bar on the headstock, similar in function to the one found on Alligator, which adds a downward force to control the break angle of the strings at the nut. PRS chose their headstock angle very carefully when designing the Silver Sky, and they don’t need a device like a string-tree or a retainer bar. On the PRS webpage you can read: “The brass nut and retainer bar bring warm, piano-like tone while promoting string vibration and resonance.” Well, I think you simply have to try if you can hear any difference in the electrified tone.
Photo courtesy of PRS Guitars
Alembic Blaster: This is for sure the biggest feature of this guitar. PRS added the active Alembic Blaster booster (formerly known as the Strat-o-Blaster) to this guitar, replacing the traditional output jack plate. This is a very basic preamp/booster design that is still available from the Alembic company. It’s not an overdrive per se; it’s a booster that makes your guitar signal louder so you can drive your amp harder, pushing it into distortion. The Alembic Blaster is powered by a 9V battery and has an internal trimpot you can reach with a little screwdriver through the hole in the plate, allowing you to dial in a boost between 3–14 dB of gain when the booster is engaged. This will add a lot of punch and muscle to your tone and is an interesting option.
Photo courtesy of PRS Guitars
If you do not want to invest in an original Alembic Blaster, you can use any other booster device—there are a lot of copies out there doing a great job.
If you’d like to build your own, the circuit is very basic and it’s just a few parts, so with some experience, it should be no problem. I found several circuit drawings on the internet containing errors, some of them in a way that the circuit will not work. Here is the original and error-free Alembic Blaster circuit for you:
Illustration courtesy of SINGLECOIL.com
If you want to build an improved version of this circuit, here is a drawing by my dear friend Bernd C. Meiser from the BSM company. It features two additional resistors (R5 as a pull-down resistor to prevent popping noises when turning the booster on, and R6 to avoid RF interferences), a different transistor, and some changed part values to make it sound more tube-like.
Illustration courtesy of Bernd C. Meiser from BSM (treblebooster.net)
Pickups: The pickups used in this Silver Sky model are the PRS 635JM, which are basically slightly hotter Stratocaster pickups with pole pieces that match the fretboard radius. All three pickups are identical except the middle pickup is reverse wound/reverse polarity (RWRP) for hum-free operation when used together in parallel with the bridge or neck pickup. The pickups can be bought separately or as a set of three. When looking at the basic parameters of the pickups (alnico 5 magnets, 6.4k DCR, 2.33 H inductance), the Fender Custom Fat ’50s and Texas Specials come to mind as a substitute, but every serious pickup company offers a set like this.
Wiring: The wiring is basically a standard Stratocaster wiring plus the active booster circuitry, so nothing too special. The 5-way pickup selector switch delivers all the well-known Stratocaster switching positions with the pickups connected together in parallel in the two in-between positions, which are both hum-free because of the RWRP middle pickup.
The three 250k audio controls are a little bit different compared to a standard Stratocaster with a master volume and the upper tone control for the neck and middle pickup while the lower tone control only affects the bridge pickup. The common tone cap is a standard 0.1 µF type.
The guitar does not have a treble-bleed circuit. The PRS standard is a 180 pF cap between the input and output of the volume pot, though I recommend using a 470 pF cap instead for better control with 250k pots. For clarity, I’ve shown the booster as a module, not the Alembic Blaster plate with the switch and the output jack installed on it. The toggle switch for the booster is a standard DPDT type. Please note that you need a stereo output jack to add power management to the circuit—the ring tab of the stereo jack is used to only engage the battery when a guitar cable is plugged in. This will prevent draining the battery by accident.
Illustration courtesy of SINGLECOIL.com
That’s it! Next time, we will talk about the Fender guitar that never really existed and its wiring, so stay tuned!
Until then ... keep on modding!
TWA CHEMICAL-Z
Roy Z signature overdrive pedal designed by TubeScreamer creator Susumu Tamura. Inspired by Maxon OD808, OD808X, and APEX808 circuits, Chemical-Z features the "Magic" IC used in APEX808 for less compression & more even frequency response than a standard 808. Increased output level. Two footswitch-selectable clipping modes - normal & hot.
Cory Wong—a funky player with his own signature-model Strat wiring.
Guitarist, songwriter, and producer Cory Wong is renowned for his solo work, his band Fearless Flyers (with Mark Lettieri, Joe Dart, and Nate Smith), and collaborations with artists such as Vulfpeck, Jon Batiste, and Dave Koz. His playing style is deeply rooted in funk rhythm guitar, with a heavy dose of rock and jazz. Well-known for playing a Stratocaster, his signature model was released in 2021, and it’s a unique offering. If you want to build your personal Cory Wong Strat, here is your shopping list, starting with the primary structure:
• Alder body, scaled down to slightly smaller than a regular Stratocaster, with Fender American Ultra body contours
• Maple neck with a rosewood fretboard with rolled edges, modern Fender American Ultra D neck profile, slightly larger headstock, 25.5" scale, 10" to 14" compound radius, 22 medium jumbo frets
• Locking tuners with all short posts, a bone nut, and two roller string trees
• Vintage-style 6-screw synchronized tremolo
• Hair tie around the tremolo springs (which mutes them to enhance the rhythm tone)
• .010–.046 strings (nickel-plated steel)
“While these are all interesting features, resulting in a very comfortable guitar, you don’t need to copy every detail to transform one of your Stratocasters into a Cory Wong-style Strat.”
For the physical build, as you can see, Wong and Fender created a real signature instrument to his specs and wishes. While these are all interesting features, resulting in a very comfortable guitar, you don’t need to copy every detail to transform one of your Stratocasters into a Cory Wong-style Strat. My personal favorite of these is the hair tie for muting the tremolo springs. A lot of my funk-playing customers are doing similar things on their Strats to get a dry sound, and they’re using all kinds of funny things in there, like foam, rubber bands, and pieces of cotton, as well as hair ties.
Now, let’s have a look at the electronics:
• Seymour Duncan Cory Wong Clean Machine SSS pickup set
• Standard 5-way pickup-selector switch with classic Strat switching matrix
• 250k master volume pot with a 90/10 audio taper and Fender treble-bleed circuit PCB
• 250k tone pot with a 90/10 audio taper and Fender Greasebucket tone control PCB for only the neck pickup
• 250k audio push-push tone pot with Fender Greasebucket tone control PCB for only the bridge pickup; the push-push switch overrides the 5-way switch and defaults to middle + neck pickup (in parallel) as a preset
• Middle pickup is without tone control
Let’s break this down piece-by-piece to decode it:
Pickups
The pickup set is a custom SSS set from the Seymour Duncan company with the following specs:
• Overwound hum-canceling stacked bridge pickup with a 3-conductor wire and shield in permanent hum-canceling mode (red wire taped off), bevelled alnico 5 magnets, approximately 14.5k-ohm DCR
• Overwound middle single-coil, RWRP, beveled alnico 4 magnets, approximately 7.1k-ohm DCR
• Overwound neck single-coil, bevelled alnico 4 magnets, approx. 7.0k-ohm DCR
The pickups are voiced for clear highs, which perfectly suits Wong’s funky playing style and tone. While a lot of pickup companies will have pickups in that ballpark, it will be difficult to put together a full set that really works as intended. The Duncans in the Cory Wong Strat are available as a balanced set, so if you want to get as close as possible, I think this is your best bet.
5-Way Pickup Selector Switch
Nothing special here, just the standard 5-way switch with two switching stages that is wired like a classic Stratocaster:
bridge
bridge + middle in parallel
middle
middle + neck in parallel
neck
The upper tone pot is assigned to the neck pickup, while the lower tone pot is connected to the bridge pickup, leaving the middle pickup without tone control.
Master volume pot and treble-bleed circuit.
The 250k master volume pot is a standard CTS pot with a 90/10 audio taper found in all U.S.-made Fender guitars. The volume pot has the treble-bleed circuit from the Fender American Pro series, but uses a ready-to-solder PCB from Fender instead of individual electronic parts. The PCB is available from Fender individually (part #7711092000), but I have some thoughts about it. While using a PCB makes a lot of sense for mass production, it has some downsides for us mortal human beings:
• Soldering on PCBs requires some training and also special soldering tools.
• The PCB is quite expensive, while the individual electronic parts are only a few cents.
• The PCB uses ultra-tiny surface-mount parts, so it’s very difficult to repair or mod it to your personal taste.
I don’t think we need a PCB for adding a treble-bleed circuit, so let’s do this project using conventional electronic parts. The treble-bleed PCB contains a 1200 pF capacitor with a 150k-ohm resistor in parallel, plus another 20k-ohm resistor in series. Using individual parts, it looks like this:
Courtesy of single-coil.com
In general, a treble-bleed circuit will help you to combat the “volume vs. tone problem” when using passive single-coil pickups. When you turn down the volume (even just a bit), the high end or treble loss is not proportionate. In other words, a small cut in volume creates a far greater loss in your guitar’s treble response. Using a treble-bleed circuit is an easy way to get rid of this problem, as long as it is calculated carefully.
ONLINE ONLY: If you want to find out more about treble bleed circuits please have a look here: https://www.premierguitar.com/diy/mod-garage/treble-bleed-mod
Next month, we will continue with part two of the Cory Wong Stratocaster wiring, bringing it all together, so stay tuned!
Until then ... keep on modding!