You can use this wiring for any guitar with the same layout. The Duo-Sonic uses a Gibson-style pickup selector toggle switch, but if you want to transfer the switching to a Fender-style, 3-way pickup-selector lever switch, you can use a guide made by Seymour Duncan, which you can find linked in this article online.
To start, let's make a list of what can be done with two pickups and a 3-way pickup-selector switch for an overview of the possibilities:
1. Neck pickup by itself
2. Bridge pickup by itself
3. Both pickups together in parallel and in phase
4. Both pickups together in parallel out of phase
5. Both pickups together in series and in phase
6. Both pickups together in series out of phase
This results in a proud list of six basic combinations instead of the typical three, which makes such a guitar much more flexible.
There is also another option with both pickups half out of phase in parallel and in series. We've discussed the basics of the half out-of-phase thing before, and I'm actually working on a useable design for this and will come back to this in a later column. The goal is to have a switch to toggle from half to full out of phase, because with a master volume and master tone configuration, you can't use the volume pot to dial in the amount of phasing you want on a Les Paul. For this you need a volume pot for both pickups, so a switch will be a suitable solution for a Duo-Sonic, Telecaster, etc.
More about the half out-of-phase basics can be found in two of my previous columns: “The Bill Lawrence 5-Way Telecaster Circuit" from October 2015, and “Decoding Jerry Donahue's 5-Way Telecaster Wiring" from June 2020.
Besides the possible pickup combinations, there are some add-ons we can implement to make such a guitar even more flexible. Something that I think makes sense would be:
1. Direct-through switch
2. No-load tone pot
3. Kill/standby switch
4. Treble-bleed network on the volume pot
There are many more add-ons we've discussed over the years, for example, TBX tone control, Grease Bucket tone control, etc., but it's easy to get lost in all the possibilities and overdo it. Who wants to end up with a guitar wiring that needs a written manual in order to operate it?
I've discussed all of these possibilities before, but today we'll combine them in one guitar. Here's a short rundown of what tones you can expect from these combinations:
Neck and bridge pickup by itself / both pickups together in parallel and in phase: I don't think we have to say anything about this combo as this is a classic guitar tone we all know.
Both pickups together in parallel out of phase: a thin, hollow tone that can be cool for playing reggae and ska music when using clean tones, or with tons of overdrive and distortion to prevent getting lost in the mix. For more details, have a look at “Adding an Out-of Phase Switch to a Telecaster," from August 2014.
Both pickups together in series and in phase: a loud and beefy tone, perfect for lead playing. For more details, read “Stratocaster Parallel/Series Switching" from December 2011 and “Telecaster Series Wiring" from June 2015.
Both pickups together in series out of phase: a very interesting sound that's much fuller and warmer compared to its parallel mate. Can be used for clean playing to add a special flavor but also for overdrive sounds. Brian May's “Red Special" guitar is one of the wirings that's able to give you this sound. See “Inside Brian May's Red Special" from October 2014.
Direct-through switch: Your signal is routed directly to the output jack, bypassing all controls for a louder tone with more high-end. Can be found under various names like “blower switch" and the like. See “Stratocaster Direct-Through Mod," from October 2009.
No-load tone pot: With the pot fully opened at 10, it will be out of the circuit, so it's half between normal operation and direct-though mode with only the volume control being active. See “The Fender Delta Tone System, Part 1" from January 2011 and “The Fender Delta Tone System, Pt. 2" from February 2011.
Kill/standby switch: This can be used to shut down the entire guitar when you're not playing, like during a break (standby switch, very similar to the standby switch you know from tube amps), or to produce a stutter-effect while playing (kill switch). See “The (In)famous Stratocaster Kill Switch" from December 2009 and “The (In)famous Stratocaster Kill Switch, Part II" from January 2010.
Treble-bleed network on the volume pot: preserves the high-end from getting lost when rolling down the volume. Check out “Deep Diving into Treble-Bleed Networks" from March 2019.
Fig. 1 — Image courtesy singlecoil.com
To prepare and fully understand this wiring, you should plan some time to read all the articles about the individual mods and what they do. That's the reason for so many links this time. It's simply impossible to cover all these individual mods again for one column—it would take up half the pages in this magazine!
For better clarity, I skipped the treble-bleed network in this diagram (Fig. 1). I described in detail in the treble-bleed article how to connect it between input and output of the volume pot. It's also up to you to use a no-load tone pot or not: I simply refer to it as “tone" in the drawing. For the parallel/series switch, the phasing switch, and the direct-through switch, you need a DPDT on/on switch. For the kill switch, you need to decide if you want a standby switch or a momentary kill switch, as described in the corresponding articles. Two of the switches can be substituted by push-pull or push-push pots, so your pickguard doesn't look like the main control unit from Apollo 11. There are even special kill-switch pots named “kill pot" that are available from the Shadow company. When you replace your tone pot with a push-pull or push-push pot, you'll have problems finding a no-load type if you want to keep this option. Your best bet is to mod your pot as described in the corresponding article.
As always, you can experiment with the type and value of the tone cap. Maybe you want to implement another mod here, like the warmth-control mod, which you can learn about in “Swap That Tone Knob for a Warmth Control" from November 2018.
If one of your pickups has a metal cover that's connected to the pickup's ground, like on most Telecaster neck pickups, you need to separate it to perform the series mod. I describe how to do that in “Preparing Your Tele for Future Mods" from May 2013.
For a better overview, I used individual switches for the diagram instead of push-pull pots. So, there we have it. Next month we'll return to our DIY relic'ing project and focus on the metal hardware, so stay tuned.
Until then ... keep on modding!
Stratocaster
Overview and considerations.
For this project, you need a guitar with three pickups—neck and bridge humbuckers, plus a middle single-coil—wired to a special 5-way switch and master volume and master tone controls.
To get the required HSH configuration, you can take an existing dual-humbucker guitar and add a middle single-coil or replace a Strat's neck and bridge single-coils with humbuckers. For most guitars, this will necessitate body routing (a job for a pro) as well as a new pickguard.
A few other things to bear in mind: While it's possible to use single-coil-sized humbuckers, you'll get the best results using standard humbuckers with a middle single-coil. In particular, it's the PRS tones that benefit from this pickup mix.
Although the middle pickup can be any standard single-coil of your choice, both humbuckers must have 4-conductor wiring. If you have traditional 2-conductor humbuckers, you can either convert them to 4-conductor wiring or simply replace them with modern 4-conductor types. I suggest considering the latter, because converting a 2-wire humbucker to a 4-wire design entails removing the cover, and this exposes the extremely delicate coil wires. In this state, it's easy to damage the pickup. Unless you're comfortable with such an operation, take the pickups to your local tech or send them to a pickup manufacturer and ask them to do the conversion for you. Again, the safest option is to use stock 4-wire humbuckers, which are readily available from dozens of companies.
Also, when wiring two pickups together and splitting a humbucker, it's easy to get lost in all kinds of out-of-phase issues when you mix pickups from different makers. To avoid inadvertent phase problems, I highly recommend using all three pickups from the same manufacturer. This will ensure that both the polarity of the magnets and polarity of the individual coils—and this is especially critical for the humbuckers—are correct in relation to each other. (In future columns I'll go into this topic in greater detail and show you how to avoid any phase troubles right from the get-go.) If you intend to combine pickups from different companies, contact the manufacturers' service departments and explain what you want to do so they can guide you through the pickup selection process.
The nitty-gritty. For this mod, you'll need a 5-way switch with four, instead of the standard two, independent switching stages. The open-framed version of this switch is available from Fender as a 5-way Super Switch, but there are also PCB-based versions of this switch. To find out more about these switches, read "Introducing Fender's 5-Way Super Switch" and "Exploring Fender's 5-Way Super Switch."
Even though the wiring resembles a circuit from the Apollo 12 mission, it's worth the work if you dream of having a vast sonic palette at your fingertips.
This project also requires an additional switch to toggle between standard Strat and PRS modes. You can either add a 4PDT mini-toggle switch or replace one of the pots with a Fender S-1 push/push switching pot. I opted for the S-1 to keep the control layout as clean as possible, but if you want to install an additional switch instead, you can convert the S-1's switching matrix to your 4PDT switch.
Another item you'll need for this project is a 500k-ohm resistor. Any type and wattage will do; I use a 1/4-watt metal film resistor because it's small and easy to work with.
Both the master volume and tone pots are 500k, a value that makes sense for the PRS mode. For the Strat mode, we have a neat little trick I'll show you in a moment. As for the tone cap, a standard 0.022 µF value will work fine. If you want a little less capacitance, try a 0.015 µF or 0.01 µF value. Either will work great for the Strat mode. If you want, you can also incorporate the typical PRS treble bleed network between the volume's input and output to keep the high-end alive when rolling back the volume. This will work for the Strat mode as well, but not perfectly—give it a try and see what you think. The official PRS method is a 180 pF "cap only" wiring.
The following chart details the 10 pickup selections in our crossover wiring scheme.
The Strat mode yields five classic single-coil tones—bridge, middle, and neck pickups solo, plus a pair of dual-pickup settings. For the latter, the humbuckers are split and the active coil is wired in parallel to the middle single-coil to achieve the Strat's signature cluck in positions 2 and 4. Depending on the humbuckers, this can work quite well.
Pushing the S-1 down gives you the switching matrix of a modern PRS equipped with two humbuckers. Position 4 sounds similar to a Telecaster's middle position, with bridge and neck single-coils in parallel, and when you add that to the available Strat and full humbucker settings, you have a lot of tonal possibilities.
Hookup tips.
Because there are so many wires to connect, I recommend approaching this in two stages. Start by soldering all the jumper wires on the 5-way Super Switch (Fig. 1) and the S-1 pot (Fig. 2). It's much easier to solder these wires before mounting the components in the guitar.
Notice the additional 500k resistor on the S-1 switch, soldered between the switch and the lug that will ultimately connect to ground. This is a cool little gimmick to get a more classic Strat tone. Here's the lowdown: A standard Strat has three 250k pots, yet here we have two 500k pots—a configuration that gives the middle single-coil more highs than we're used to hearing on a Strat. By adding this 500k resistor in parallel, the middle single-coil will sound like it's in a 250k environment when the S-1 is in Strat mode.
Fig. 3 is the full schematic. I used Seymour Duncan's color code—a standard for such drawings. If you're using pickups from a different manufacturer, simply convert the color code of the wires, following the manufacturer's instructions. To keep the schematic as clean as possible, whenever multiple wires lead to the same spot, I combine them in the drawing. In such a complex wiring, it's very easy to mix something up, so be patient and work methodically. Go one step at a time and double-check each connection.
Next time, we'll begin investigating pickup parameters to learn how to interpret them and what they can tell us about a given unit's sound. Until then ... keep on modding!
[Updated 9/27/21]
Red Special history.
Guitar freaks know the story about May's main axe and how as a kid he built it with his father in the early '60s. From the moment May started playing with Queen—filling stadiums worldwide and recording monster hits—the Red Special's distinctive tone has been essential to his music. What makes this guitar different?
The Red Special boasts three single-coil pickups, Telecaster-style master volume and master tone knobs, and individual on/off and phase switches for each pickup. Like some older Danelectros, its pickups are wired in series rather than in parallel, and this yields a very fat, loud sound.
Photo by Chris Kies
The theory behind series wiring is that the ground wire of one pickup is connected to the hot wire of another pickup. As a result, they become a kind of compound pickup with one ground and one hot for both.
When wired in series, the pickups' impedance (resistance) is summed and the output is very high. (To learn more about series wiring, read "Stratocaster Parallel/Series Switching.")
May's original Red Special is constructed with unusual materials.
The body is made of oak and blockboard, and topped with a mahogany veneer. Its center block and neck consists of an unknown wood taken from an old fireplace mantel, and the fretboard is oak. The result is a kind of semi-acoustic guitar that's almost impossible to copy, but a standard Strat isn't a bad foundation.
If you're intrigued with the idea of configuring a Strat à la May, Image 1 is the wiring diagram for a stock Red Special. Naturally, you can physically arrange the on/off and phase switches to your personal taste.
Pickup details.
A big part of May's tone comes from the Red Special's Burns Tri-Sonic pickups. Though Tri-Sonics are single-coils, they're wider than standard Stratocaster pickups. This means if you want to install a replacement set of Tri-Sonics in your Strat, you'll have to enlarge the pickup holes in the pickguard and reroute the pickup cavities in the body. Fortunately, Burns also offers a drop-in replacement for Strat pickups called the Mini Tri-Sonic. These pickups sport ceramic magnets and a chrome cover, and have a typical DC resistance of around 7k ohms and an inductance of approximately 1.9H.
The Tri-Sonic's unique construction gives it richer harmonics than a standard Stratocaster pickup. In fact, a Strat-sized P-90-style pickup will get you closer to Brian May territory than a Strat pickup. But to get as close as possible, Tri-Sonics are the ticket.
The Red Special boasts three single-coil pickups, Telecaster-style master volume and master tone knobs, and individual on/off and phase switches for each pickup.
Instead of a common 5-way pickup selector switch, May uses an on/off switch for each pickup. This arrangement gives him seven different combinations from the three pickups. Besides the five well-known Strat combinations, he can also pair the bridge and neck pickups, as well as engage all three pickups. His Red Special uses slide switches, but mini-toggle on/off switches work just fine.
A passing phase.
On his Red Special, May also incorporates an individual phase switch for each pickup, so he can reverse its phase in any pickup combination. When two pickups are in phase, they work together and sonically reinforce each other. When they're out of phase, two pickups work against one another, cancelling many frequencies. The resulting sound is the "leftovers" from these cancellations.
Before we go any further, let's review two things about switching pickup phase: You don't have to engage two phase switches—reversing the leads of both pickups puts them back in phase again and thus yields a stock sound. And switching the phase of a single pickup has no audible result. For example, the bridge pickup by itself sounds the same whether it's switched in or out of phase. You can only get an out-of-phase sound when you use two pickups together and only one of them is out of phase.
So why add all these phase switches?
Consider this: There are two ways you can use the bridge and middle pickups together with one of them being out of phase with the other. The bridge pickup can be in phase and the middle out of phase, or the other way around. Each configuration delivers different harmonic content, especially when you're playing with distortion. The difference is subtle, but audible, and May is known for tinkering with this option a lot. It's an important part of his signature tone.
May typically plays with heavy distortion, pushing his amps hard with those series-wired Tri-Sonics. His out-of-phase sounds are an excellent choice for cutting through the mix, and this whole circuit is perfect for his playing style.
To get close to the Brian May tone, there are several more things to consider: He plays with very light strings (.009–.036) and uses an old sixpence coin as a plectrum. He also runs his guitar into a treble booster and a wall of Vox AC30s. There are other details, but to enter the May zone without breaking the bank, use thin strings, pick with a coin, plug into any Rangemaster Treble Booster clone, and use a Vox amp—ideally an AC30.
There is a Vox Brian May signature amp (the VBM-1), which was designed to mimic his studio sound and has a built-in treble boost circuit. Though the amp is no longer in production, it sometimes shows up used on eBay.
There are a lot of mods out on the web for Red Special replicas and clones, mostly designed to coax more sounds out of the guitar. My favorite (Image 2) is by John Hewitt, an Australian guitar tech and the mastermind behind the GuitarNuts website. This mod incorporates series/parallel pickup switching, leaves all stock wiring sounds untouched, and only requires one additional switch, which acts as a master series/parallel switch. Parallel switching of the pickups offers more traditional Stratocaster tones. Compared to the series wiring, it has reduced output but delivers enhanced clarity, twang, and top end.
All you need for this is a 4PDT mini toggle or slide switch. A mini toggle switch should be easy to acquire, but finding a 4PDT slide switch can be more difficult. Using the new switch is fairly simple: Dial in a pickup combination of your choice—for example, bridge-plus-middle—and you'll hear them connected in series (the stock wiring). If you want a more Strat-like sound, flip the new switch and both pickups are now wired in parallel for a more traditional tone. Flip it again and you are back to the stock series wiring.
This isn't an easy wiring project, so be methodical and don't rush through it. The third pickup wires (not shown in Image 2) from the Tri-Sonics are twisted together and soldered to ground as shown in Image 1's stock wiring (represented in green).
And that's it! Until next time, keep on modding!
[Updated 9/28/21]