The Fender Delta Tone System, Part 1
December 21, 2010
Here’s what Fender says about the Delta Tone system:
The Delta Tone wiring features a no-load tone control for the middle and bridge pickups, great for producing just a bit more midrange and hotter output from the Stratocaster. The no-load tone pot works like a standard tone knob from positions 1-9, but at 10, it is removed from the wiring completely so that you get the full, unadulterated sonic output of your pickup. It means more output and more treble without using a booster pedal or active controls.
If you want to add a Delta Tone system to your own Strat, it’s not too hard. First, you need to choose a replacement bridge pickup. Given the virtually countless Strat pickups available today, it should be easy to find a good, slightly overwound bridge pickup. For example, Fender offers Custom Shop Texas Special Strat pickups as a set (part 0992111000) or individually.
After installing the hotter bridge pickup, you’ll have to change the configuration of the tone controls on your Strat’s 5-way pickup selector switch, but you already know how to do this, right? We explored this in detail in several of my earlier columns. In a nutshell, you only have to add a short jumper wire between terminals 1 and 2 on stage 2 of the 5-way switch.
The last step is to replace the tone pot (which is now shared by the bridge and middle pickups) with a no-load pot. This is available from Fender in several versions. For a standard Strat, the 250 kΩ version with a split shaft (part 0990832000) will work perfectly.
So what exactly is a no-load pot? As Fender’s literature hinted, it has a detent at position 10 that completely bypasses any filtration via the tone capacitor and the load of the pot itself. Unlike the TBX tone control, which has a detent at position 5 (the middle setting) and gradually reduces the amount of filtration through the capacitor, the Delta Tone’s no-load feature eliminates it completely at the detent. As a result, you hear more of the direct, naked sound of the pickup.
To get an idea of this tone, you can do a little experiment before you decide to replace the pot. Plug in your Strat and play a favorite song—something you know inside out—using the middle pickup. Next, desolder the middle pickup from the 5-way switch and solder the two leads directly to the output jack. Now play the song again. It’s a stunning difference, no?
What you now hear is the true tone of your middle pickup in all its sonic glory. The sound is noticeably louder, richer, and full of detail. Why? Because when it’s connected to the Strat’s electronics, the pickup is colored by the tone capacitor, the load of the pots, the wiring, and, to a small degree, even the 5-way switch. The extent of the loading effect depends on a guitar’s pickups and wiring, but eliminating it is often described as “removing a blanket from the amp.” If you like this naked pickup sound, a no-load configuration is worth a try. Because only the pot and tone cap are removed from the circuit, the result won’t be exactly the same as the direct-to-output jack experiment, but it comes close.
Naturally, you can replace both your Strat’s tone controls with no-load pots for even more flexibility. But on a Strat with standard wiring, you can’t use a no-load pot as a volume control. If you try, you’ll have a very silent guitar with the volume knob set to 10!
Next month, we’ll take a closer look at no-load pots and how to convert a standard pot into a no-load pot. Until then, keep on modding.
Dirk Wacker lives 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—singlecoil.com—on the subject.