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!
Many years ago distortion pedals were much more limited than they are today. MXR released a simple hard clipping device called the “Distortion Plus” in the late seventies. Randy Rhoads, among others, used this pedal to achieve more distortion in his amps. Guitarists everywhere mistakenly thought that this little device was the secret to Randy’s tone. Since then, there have been many, many different versions of this type of circuit. Let’s take a look at it a bit closer; there are a great many mods that can be done to turn it into a tone monster.
Here''s the stock circuit:
The signal enters where C1 and C2 intersect. C1 is a low pass filter, throwing some highs to ground pre-clipping. C2 allows mainly mids and highs through into the clipping section. The R1 limits the signal going into the opamp and R5 sets bias for the opamp.
R4, C3, R2, and R3 control the gain and frequencies getting boosted and clipped in a traditional “non-inverting” method of opamp circuit. R3 is labeled as a gain control, however you’ll notice that it changes the tonality depending on its setting. This is because it is changing the frequency response of the opamp at the same time. With the gain control all the way up it only clips frequencies 723hz and higher, though it is at max gain. In its minimum gain setting it is boosting and clipping almost all frequencies (3.4hz and higher) though it has much less gain. This is why it sounds muddy and undefined when the the gain is lower and why it thins out when you turn the gain up.
After the signal is boosted it exits through C4 and then through R6. D1 and D2 clip the signal using a “hard clipping” method while C5 works with R6 as a low pass filter to filter out 6db worth of frequencies 15.9khz and above, which the human ear can’t really distinguish too much. Most likely this was to filter out some odd harmonic overtones and/or noise. A much better use would be to wire a 100k pot in series with a .0022uF cap in place of C5. This will act as a tone control.
D1 and D2 are 1n34a type Germanium diodes in the stock version. This leads itself to a bit of a fuzzy compressed tone with not much volume left over after being clipped.
The signal exits via the 10k pot on the output.
The Dod OD250 and YJM308 circuits are almost identical to this and these mods will work for these pedals as well.
Here some of my favorite mods that I like to make to this type of circuit:
- Use an SPST switch to insert a .01uf cap in parallel with a .001uf cap in place of C2. This will give a ''more/less compression'' type of function, or a ''smooth/open'' tonality. For a more dramatic effect, make the .01uf a .047uf or so.
- Add an SPST switch around C3 to add more bass by adding a .33uf cap in parallel with C3.
- Change R2 and C3 to a 1k/.22uf for the same high gain frequency response but more gain potential
- Change R4 to a 1m audio taper pot for better response through gain adjustment.
- Add an SPST switch to add in diodes in parallel with R4. I have 1n34a and 1n4001 diodes shown here, though any can be used.
- Change D1 and D2 to 1n34a and 1n4001 diodes (in series) in place of each stock diode for louder output as well as better dynamics.
- Change C5 to a .0022uf and wired in series with a 1m audio taper pot to act as a tone control.
These mods will make your pedal into a much bigger, fuller, nicer (or meaner) sounding distortion or overdrive. While not all of the mods are necessary, I encourage you to experiment to find what you like and don’t like and tailor your own pedal to your needs.
Happy Soldering!