This month we’re checking out another Strat mod that’s very easy to do and that offers a lot of utility. And it’s cheap! All you need for this mod is a simple on/off toggle and a capacitor—that’s it. The idea is based on the stock Fender Telecaster wiring from the early ’50s.

As you may know, until 1967 Fender used a different wiring for Telecasters than the scheme we know today. On standard modern Teles, the wiring is bridge pickup alone, both pickups together in parallel, and neck pickup alone. But prior to 1967, Fender used the following wiring: bridge pickup alone, neck pickup alone, and neck pickup alone with an additional 0.1 μF cap engaged. (We’ll explore this old-school Tele wiring in a future column, when we switch from Stratocaster to Telecaster mods.)

In Fender literature from the era, this neck-pickup-plus-capacitor wiring was described as a “pre-set bassy sound,” and the idea came from Leo Fender himself. Leo believed guitarists should have the capability of playing bass lines without switching instruments. After experimenting, he came up with this solution and the result was a boomy, bassy tone that didn’t require an additional tone knob. This was intended as a “bass preset” that would allow a guitarist to simply flip the 3-way pickup selector to enter bass territory. For this reason, the mod I’m about to describe is often called the “bass switch mod.”

The preset idea is something Fender used in several other guitars as well, including the Jaguar. However, it turned out Tele players didn’t want to play bass lines, and once the Fender P bass was invented (it came soon after the Telecaster), this bass preset remained mostly unused or fell victim to early modifications. When Fender finally changed the wiring, it was a concession to countless customers’ demands and an admission that this preset tone was more or less unusable.

After 1967, this wiring option was almost forgotten. But in the early ’80s, adventurous jazz players like Mike Stern discovered that old Telecasters made a durable alternative to an expensive archtop jazz box. Suddenly, the old Fender preset wiring was something desirable and practical. It worked perfectly for those dark, jazzy tones certain guitarists were looking for, and a new hype was born. Some players stayed with the stock Fender wiring, while others started to experiment with different cap styles and values. Leo Fender never intended his wiring for this kind of “abuse,” but even today, it’s the standard for a lot of jazz players all around the world. So if you want to throw in some cool jazz lines without messing with your Strat’s tone knobs, this preset mod is for you.

I’ve adapted the preset to accommodate any Stratocaster wiring and to work in conjunction with all the standard 5-way-switch pickup combinations. To summarize: You won’t lose a switching position on the 5-way switch, yet you’ll receive a lot of different new tones because the mod works with all pickup combinations. To mimic old-style jazz tones, people recommend using the Strat’s neck pickup, but I also like using the bridge-and-middle pickup combination with this mod.

First, you’ll need an on/off switching device. You can use a mini toggle (which is what I prefer) or any kind of push/pull or push/push pot. The advantage of using a pot is that your Strat will remain visually unaltered.

Second, you’ll need an extra capacitor to throw into the circuit. This area offers a lot of opportunity to experiment. You can try different cap styles—like paper-in-oil caps, foil/film caps, old-style paper-waxed caps, ceramic, and so on. For this application on a Stratocaster, I prefer the warm and growly character of new-old-stock (NOS) paper-in-oil caps. But there’s no right or wrong—it’s only the tone that matters, so if you like it, use it.

A cap’s value (or capacitance, to be more precise) provides even more options to tinker with. You can stick with the original Fender value of 0.1 μF, but most players feel this is over the top and simply generates too much bass. A good range to experiment with is from 5000 pF up to 0.05 μF—and everything in between. The results depend on a lot of factors, such as the pickups, the Strat’s neck and body woods, your cable, and your amp settings. With a Strat, I find NOS 0.05 μF paper-in-oil caps sound good with any Fender amp. Marshall players should lower the value a little—0.033 μF is a good compromise.

Technically, this mod is very simple. Flipping the switch, you engage the additional capacitor and send some highs to ground. Just how much depends on the capacitance of the cap you choose. Think of it as a slimmed-down version of the Gibson Varitone circuit, which is based on the same principle but uses a rotary switch to dial in several different caps to achieve different tones. (We’ll talk about the Varitone circuit in a future column on Gibson mods.)

After you’ve installed the switching device of your choice, you only need to connect the capacitor to the switch, with the other side of the cap going to ground. Connect the other switch lug to the hot lug of the output jack, where it joins the wire coming from the volume pot. Done! The diagram shows how to connect everything. [A larger image is available in the online version of this month’s column.]

This mod isn’t difficult, and it enhances your tonal palette— especially when you want to throw in some jazz lines. Stay tuned for more Strat mods coming next month. Until then, keep on modding!

Dirk Wackerlives in Germany and is fascinated by anything related to old Fender guitars and amps. He plays country, rockabilly, and surf music in two bands, works regularly as a session musician for a local studio, and writes for several guitar mags. He’s also a hardcore guitar and amp DIY-er who runs an extensive website——on the subject.