Fig. 1
This guitar wiring is special in that the two tone controls are freely assigned, and the tone control is bypassed in the two in-between positions. Let’s go under the hood.
Hello and welcome back to Mod Garage. This month, we’ll have a look at the Scott Henderson Strat-style wiring and what it means to bypass the tone control for certain pickup-switching positions.
Bypassing the tone control in a guitar circuit has become popular in recent years, so let’s explore how to do it. We’ve discussed this before in the context of using no-load pots for the tone control. A no-load pot will be electrically out of the circuit when it’s fully opened, so the pot is no longer part of the wiring, and will add no load to the circuit. This way you will have no high-end dampening and the tone is a tad louder, which can be a good thing or not, depending on your personal preferences.
This works great but requires that you open the tone pot(s) if you want this very direct sound. Some players like to have a kind of preset without tone control so there is no additional action they have to take. So, the basic idea of bypassing the tone controls is to transfer it to the pickup-selector switch rather than using no-load pots. There’s no law against combining this mod with no-load pots for the tone control, so you still have the opportunity to use it for sounds where the tone control is engaged.
The credits for this wiring are given to John Suhr, but it’s unknown if he came up with this special wiring during his time as a Senior Master Builder in the Fender Custom Shop, or later, after he started his own business in 1997.
The preset idea is not a new one. Fender has used it since the early ’50s, and the basic idea behind it is still the same. Imagine the following scenario: You’re playing the bridge pickup on your guitar with the corresponding tone pot set to 7 to add some warmth to your tone. In the middle of a song, you need to switch to another pickup that is connected to the same tone pot, but you need the tone pot fully opened to cut through the mix with this pickup setting. Two steps are required now: You need to switch to the desired pickup position, and you need to open the tone pot. Wouldn’t it be nice to have this happen by only dialing in the other pickup position? This is exactly the idea behind bypassing the tone control.
To illustrate, I chose the personal S-style wiring of the award-winning fusion, jazz, and blues guitarist Scott Henderson. The credits for this wiring are given to John Suhr, but it’s unknown if he came up with this special wiring during his time as a senior master builder in the Fender Custom Shop, or later, after he started his own business in 1997.
Henderson is best known for his solo work but also for his band Tribal Tech, as well as for playing with Chick Corea and the Zawinul Syndicate. Henderson released his first solo album, Dog Party, in 1994 and has six solo albums to date. He’s also a teacher at the Guitar Institute of Technology, now known as the Musicians Institute in Hollywood, California. His signature S-style guitar is built by the Suhr company. Henderson and John Suhr got to know each other while Suhr was still working at the Fender Custom Shop, and Henderson became one of the first endorsers for Suhr Guitars.
Henderson wanted an exclusive tone control for the bridge pickup and full clarity in the two in-between pickup positions, so this wiring is exactly what he was looking for.
Henderson’s personal wiring is basically a standard Stratocaster wiring you all know:
- bridge pickup alone
- bridge and middle pickup together in parallel
- middle pickup alone
- middle and neck pickup together in parallel
- neck pickup alone
What makes this wiring special is that the two tone controls are freely assigned, and the tone control is bypassed in the two in-between positions. So, the switching matrix for the Henderson wiring goes like this:
- bridge pickup alone with tone control #1
- bridge and middle pickup together in parallel with no tone control
- middle pickup alone with tone control #2
- middle and neck pickup together in parallel with no tone control
- neck pickup alone with tone control #2
Henderson wanted an exclusive tone control for the bridge pickup and full clarity in the two in-between pickup positions, so this wiring is exactly what he was looking for. Another benefit is that the bypass of the tone controls for the in-between positions is slightly compensating for the little volume loss, which is the nature of the (passive) beast when you combine two pickups in parallel.
In a Strat with two tone controls, changing the standard 5-way pickup selector switch for a 5-way super-switch is mandatory because you can’t do all this with only two switching stages. We don’t need all four switching stages of the 5-way super-switch, so one stage will stay unconnected.
Technically, these are 4P5T wafer switches, and they’re available as open frame as well as PCB-based versions. These switches are physically a lot larger than the standard ones, so depending on what guitar you have, you can run into massive problems to make them fit without rerouting your electronic compartment. Always check this before you buy such a switch to avoid any unpleasant surprises. To make the open version from Fender fit, you need at least 21 mm of space for the switch, but it’s better to have 25 mm to avoid any problems with the soldering terminals.
So here it is, the Henderson wiring as seen in Fig. 1. This wiring uses three 250k pots, a 0.047 µF tone cap, and no treble-bleed network on the volume pot.
That’s it for now. Next month, we’ll continue the tone-pot-bypass journey by looking at a Telecaster wiring, so stay tuned.
Until then ... keep on modding!Photo 1 shows the 4PDT switching matrix design for the "up" position, which will put the pickups half out-of-phase.
We've discussed full out-of-phase and half out-of-phase pickup switching. Here's a wiring for those who want it all in one switch.
Hello and welcome back to Mod Garage. After exploring the half out-of-phase pickup option several times in the past, there was a lot of interest, and I received a lot of emails from readers about it. A lot of you asked for a multi-phase switch to have all possible options at the ready and today we'll bring it all together. You asked for it, and the Mod Garage delivers!
Let's start with what we'll need to get out-of-phase or half out-of-phase sounds:
- You will need to engage at least two pickups to get such sounds. A single pickup played by itself will always sound the same, no matter if you play it in phase or out of phase (more about this later). The magic starts when you engage two (or more) pickups with one in phase and the other one out of phase or half out of phase.
- In general, you'll need one switch for each pickup you want to put out of phase. This can be only one switch, like on the middle pickup of a Stratocaster, to cover both in-between switching positions (bridge+middle and neck+middle), or three phasing switches, like on Brian May´s "Red Special," with one switch for each of the three pickups.
My design of a multi-phase switch that we'll cover today can be used to expand already existing out-of-phase switches in a guitar or to design a new wiring of your choice, integrating such a switch. With this switch, you'll be able to cover all three possible phasing options: in phase, out of phase, and half out of phase.
The magic starts when you engage two (or more) pickups with one in phase and the other one out of phase or half out of phase.
All you need for this mod is the switch, plus a capacitor and a resistor for the half out-of-phase option. So, let's start with the switch itself. For this mod you need a 4PDT on-on-on switch, which means a switch with three switching positions (up-middle-down) and a total of 12 lugs, arranged in four independent sections. Such switches are on the border of being exotic, but they're still available. Since every manufacturer uses a slightly different switching matrix for such switches, you'll need to get one with the same switching matrix I used, which is more or less the quasi-standard for it. It's possible to use 4PDT switches with a different switching matrix, but you'd have to adopt the wiring to it. I've provided three photos of the switching matrix and the switch design for each position. Photo 1 shows the "up" position, which will put the pickups half out-of-phase. Photo 2 shows the "middle" position, which will give you the full out-of-phase option. And Photo 3 shows the "down" position, which is just the normal in-phase operation.
Placing such physically large-sized switches on a pickguard or control plate can be a challenge, so you'll have to be creative. There is no way around such a switch when you want this mod because there are no existing push-pull or push-push pots with on-on-on switches. If you can find a 4P3T rotary switch, you can use it to substitute the switch by replacing one of the pots with it. There are also 4PDT slider switches available, but they're physically about the same size, and therefore, not a real alternative.
Photo 2 shows the 4PDT switching matrix design for the "middle" position, which will give you the full out-of-phase option.
Image courtesy of singlecoil.com
Here we go with the wiring of the switch, shown in Fig. 1. With the lever down you have the normal in-phase operation, with the lever up the pickup is half-out-of-phase, and in the middle position you have the full out-of-phase option.
Anyway, there you have it, all in one switch as shown in Fig. 1. On the left side of the switch, you see a capacitor in series with a resistor for the half out-of-phase option. A good average value is using a 0.01 uF capacitor with a 6.2k-ohm resistor in series as an additional serial attenuation of the system, preventing an impedance peak.
When looking at the switch, you'll notice that one switching stage is not populated at all. You might ask: Why don't we use a 3PDT switch for this if we only need three switching stages? This is because of the asymmetrical switching matrix of the 4PDT switches in the middle position (Photo 2) and there's no way around it. If the on-on-on switch had a completely symmetrical switching matrix, then three switching stages would be enough, but such switches aren't available today.
Photo 3 shows the 4PDT switching matrix design "down" position, which is just a normal in-phase option.
Image courtesy of singlecoil.com
In general, you add a controlled degree of reversed phase of the pickup when using the half out-of-phase option, which is great to mimic Stratocaster in-between "quack tones" on a Telecaster, like on the Jerry Donahue Tele models or with the Bill Lawrence Telecaster wiring.
Phase differences are measured in degrees. Totally in-phase sounds have either 0 or 360 degrees of difference, meaning none. Totally out-of-phase sounds have a 180-degree difference. So, half out of phase is either 90 or 270 degrees of difference. That's the reason why you can only achieve a fully out-of-phase effect when using two pickups together with one wired out-of-phase. (When both pickups are wired out of phase, they sound the same as both pickups in phase, because there are still 0 degrees of phase difference between them.) When a signal passes through a capacitor, the voltage leads the current by 90 degrees, so when a pickup's signal gets routed through a capacitor, it shifts the phase by 90 degrees—exactly half of 180 degrees—and therefore half out-of-phase ... in simple terms.
The cap connected to the switch is the phase-shifting cap mentioned above. A 0.01 uF cap is a great starting point, but you may try caps between 0.005 uF (5000 pF) and 0.022 uF. The smaller the cap, the sweeter the sound will be, but this really depends on your particular pickups. I recommend experimentation and fine-tuning to get as close as possible to a Strat's in-between tones.
As for the attenuation resistor, a 6.2k-ohm resistor works pretty well with the 0.01 uF cap and standard single-coil pickups. As a simple guideline, you can follow this rule by choosing and experimenting with this resistor: The higher the value, the more attenuation in the system, the smaller the impedance peak. A good starting point is the DCR of the pickup that's connected to the switch. For example, if your pickup measures a DCR of 6.8k ohms, you should start with a 6.8k-ohm resistor on the switch for a balanced sound and experiment from there. A good option is to use a small trim pot first so you can experiment until you find the value you like best. You can measure the trim pot and solder a fixed resistor with the measured value on the switch, or simply leave the trim pot where it is. A 10k or 15k trim pot is perfect for this.
That's it for this round. In honor of Fender's 75th Anniversary, next month we'll take a deeper look into Fender's history, busting some myths, misunderstandings, and urban legends, while celebrating the man behind the company that started it all: Mr. Clarence Leonidas Fender, or Leo Fender, as the world calls him.
Until then ... keep on modding!
Photo 1
Here are four ways to ground individual lugs to pots, two ways to connect ground wires to pickups, and a clever soldering technique developed by my colleague Mark Foley.
Welcome back to Mod Garage and to the second and final column about grounding in passive guitar and bass circuits. If you missed the first part, check out "How to Ground Passive Guitar (and Bass) Circuits, Pt. 1," from April 2021. Today we'll discuss grounding individual lugs on pots, which is usually the case on all volume controls, but also on some certain tone pots, depending on how the circuit is set up.
To resume from the first part, please remember that the goal is to connect an individual part or piece in the circuit to ground, and the quality of a ground connection inside a passive circuit is not dominated by the gauge of the wire that's used. So, the more the merrier may look cool, but it's simply not necessary to overdo it here. Personally, I use a silver-plated, solid core AWG24 copper wire that looks nice and shiny and is also a joy to work with.
Let's start with version #1, the method that started it all: soldering the lug directly to the casing of the pot. This is the version Leo Fender used (remember: Leo didn't waste time on anything that wasn't necessary), but Gibson and all others used it as well. I like to call it the "cowboy version," or, for you Trekkies: This is the version James T. Kirk would have chosen when he would be into guitar-circuit soldering.
The handle of the cage is used to connect all three ground wires from the pickups individually, so it's easy to remove only one when you need to without adding any more heat to the case.
This is the most basic version and it's simply about bending the lug towards the casing of the pot and soldering both parts together as shown here in our example on a Stratocaster volume pot from 1965 (Photo 1). This sounds easy but it isn't. When you're not restoring a vintage guitar, I recommend using one of the other versions that follow. Depending on the pot, chances are good that you'll break the lug easily while attempting to make it touch the casing. This isn't the end of the world, but avoidable trouble.
Let's assume you managed to bend the lug towards the case without breaking it. You'll need a really hot soldering iron to connect both parts with each other, and soldering time will be a little bit longer than usual. The chance of overheating the pot is something to consider. With a good and quick soldering technique that comes with experience and the right tools, it's doable, but avoiding overheating is important to not kill your pot. If you're working on a vintage guitar, be very careful to not break the lug while bending it. Take care to clean both contact points and use a heatsink wherever possible. For more tips about soldering to pots, please read this column I wrote last year: "How to Install and Maintain Your Guitar's Pots."
Photo 2
Courtesy of singlecoil.com
All following versions are the "Gentleman versions," or, for the Trekkies out there: These are the versions Jean-Luc Picard would choose. Version #2 involves extending the ground wire. This is easy and neat to do when you're running a bare ground wire from pot to pot. Instead of soldering it directly to the case of the pot, run the wire though the lug of the pot you want to ground and solder it as shown here in a Stratocaster wiring example using a shielded output wire to the jack (Photo 2).
Photo 3
Courtesy of singlecoil.com
Version #3 is a kind of variation of version #2, using the grounded lug as the ground connection for the output jack, as shown here on a vintage-style Stratocaster wiring (Photo 3). Simply extend the ground wire for the output jack though the lug and solder it to the case and the lug, and you're done. I really like to use this version for a clean wiring, and as long as all pots are grounded this one works pretty awesome.
Version #4 is using a ground strap. When you're using a ground strap from pot to pot, you already must solder it to the case of the volume pot. Instead of heating up the case for a second time to connect the lug to ground, it's much more reasonable and easier to connect the lug to the ground strap. For this you have three choices:
1. Leave some slack on the ground strap so it touches the lug.
2. Bend the lug upwards so it touches the ground strap. Do not break it!
3. Solder a piece of wire to the lug and the other end to the ground strap.
Photo 4
Courtesy of singlecoil.com
In our example, shown in Photo 4, I used the slack method, so soldering was easy.
Photo 5
Courtesy of singlecoil.com
Now let's have a look at how to connect the ground wires of the pickups to ground, starting with the method Fender used right from the start on the Stratocaster: soldering all three wires side by side on the case (Photo 5).
Here you can clearly see: The lug is directly soldered to the case and the additional black wire you see is the ground wire from the output jack, so this case had to stand a lot of heat during the installation process. The advantage of this method is it's easy to change only one pickup if you need to by unsoldering only its individual ground wire. The disadvantage (besides the large amount of heat to the case) is that you need some practice to master this method because you must hold all three wires in place while soldering and usually need three hands for this (another one of those "alien tasks" in lutherie).
Photo 6
Courtesy of singlecoil.com
A really good alternative is to twist and solder all three ground wires together, so you only have one small soldering spot on the case (Photo 6). This is quick and easy to do, looks neat, and saves you some time, nerves, and exposed heat to the pot's case. You can also extend the twisted part to the lug you want to ground, similar to version #3 above, only the other way around. The disadvantage is that it's not so easy to change only one of the pickups if you need to. You'll have to unsolder all three ground wires, cut off the twisted part and pull out the wire you need.
Photo 7
Courtesy of Mark Foley/mfguitarproducts.com
In closing, I want to show you a really cool version that brings it all together that my friend Mark Foley, from MF Guitar Products in the U.K., is using.
Foley builds a kind of cage on the volume pots, connecting the lug with a piece of wire to another piece of wire (Photo 7). The intention and advantages are clear to see: Bending a lug downwards is much easier than upwards and the chance of breaking it is very minimal. Besides this, you only have two small soldering spots on the case that are quick and easy to do, saving a lot of heat on the case. So, what is the "handle" running across the case of the pot for? Is it only for connecting the wire coming from the lug? No, the best part is yet to come.
Photo 8
Courtesy of Mark Foley/mfguitarproducts.com
The handle of the cage is used to connect all three ground wires from the pickups individually, so it's easy to remove only one when you need to without adding any more heat to the case (Photo 8). It's also the perfect connection point for any other ground wires in the circuit, like the ground wire from the output jack, the string grounding wire coming from the tremolo claw, etc. And it's also a great guide for the hot wires from the pickups on their way to the pickup selector switch, so you don't need to use any additional tape, cable ties, or whatever else to bundle the wires. Is that a cool and clever solution, or what?
That's it for the topic of grounding. Next month we'll explore our next guitar mod, so stay tuned. Until then ... keep on modding!