This is the conclusion to the Perfect Switching article. Again, let me warn you that this page assumes you know a little bit of electrical wiring and reading basic schematic diagrams. If you don’t know what “parallel” or “series” wiring means, this page will provide you with some basics: http://www.1728.com/guitar.htm.

Last week, I showed you alternative pickup switching possibilities that can give you a wider range of tones to choose from. We’ve come a long way from the paltry 3-way switch of the Les Paul, to the Strat’s 5-way switch, then the Red Special’s 7 combination switching using 3 switches (not including phase-switching), we have 13 combination switching using 4 switches. This week, we will conclude this series with some more ideas. Whether we incorporate these additional ideas or not is subject to deliberation. On one hand, we want to squeeze as much juice as we can from our pickups. On the other hand, we do not want to end up with a guitar that looks like a 60s era rocket ship cockpit.

Double Coils

You may use either single or double coils (humbucking). Cycfi Alpha uses DiMarzio Area 67 pickups which are actually noise canceling double coils voiced after the bright and very clean Fender Strat 67. I am not quite fond of noisy single coil pickups. For double coils, coil tapping and series-parallel wiring of its coils offer additional tonal variations. Coil tapping involves switching off one of the coils giving you single coil capability. That makes the pickup very susceptible to noise, so that’s out of the question. It may be nice to have each humbucking pickup have its own series-parallel switch though. The circuit will be like what we have (see Basic Building Block in part 2 of this article) except that the SW2 is not needed and is hard-wired for the 2 pickup setting. Food for thought.

Series-parallel switching for double coil pickups

Phase switching

When two or more pickups are connected and one pickup is reverse-wired,  the signal of the reverse-wired pickup is out of phase and cancels out certain frequencies. The result is a thinner, squawky sound with a dramatic decrease in volume. You need a DPDT switch to reverse-wire a pickup. For a 3-pickup setup, you only need 2 switches, not 3. You only need to provide phase-switching for the neck and bridge pickups. The first part of this article explains why: 3 phase-switches give you redundant configurations and you can get the same results with only two switches.

Here’s the schematic:

Phase switching circuit

I have mixed feelings with phase switching. As-is, I find it barely useful only in very special cases. However, it might be interesting to limit its effect by incorporating a potentiometer that will act as a pickup blend control. When all pickups are in-phase, the blend controls will be additive (boost). When a pickup is reverse-wired, its blend control will be subtractive (cut).

Ease of use

Usability matters. No matter how impressive a feature is, bottom line, it will not gain traction if it is difficult to use. The use of multiple switches makes it a bit more complex to use. It may be argued that beauty of the Strat or the Les Paul lie in their inherent simplicity. That may be true. As Einsten said, “keep it as simple as possible, but not simpler”. With the tried and true, you can’t go wrong. It’s simple and effective. However, by going the same path over and over again, we fail to explore unseen possibilities and ultimately, it becomes boring.

Multiple switches may be tricky to use at first, especially when you are accustomed to the single multi-position switch. However, I don’t think this should be a problem with the modern guitarist with his/her full arsenal of gadgets. Hey, guitarists do a lot more complicated finger gymnastics! Guitarists I know love to experiment and explore.

Refering to the schematic (disregarding phase switching and double coil switching),  the “user interface” is really quite intuitive. We have 4 switches. 2 switches (SW2 and SW4) control compositing (mono/duo):

• SW4 controls whether we combine pickups B and C
• SW2 controls whether we combine A and whatever the setting of SW4 is (mono B or C or duo B and C).

Assuming SW2 and SW4 are in mono, the other 2 switches (SW1 and SW3) control pickup selection.

• SW3: switches B or C
• SW1: switches A or whatever we chose with SW3 (B or C). Think of it as the “lead” switch. If A is the bridge pickup, flicking SW1 will always give you the bridge pickup.

The following table gives you the settings that correspond to the Strat’s 5-way switch:

• Sw3 chooses B (middle pickup) or C (neck pickup)
• Sw4 combines both B and C
• Flicking Sw1 switches in A (bridge pickup) regardless of the setting of Sw3 and SW4
• SW2 combines A and whetever the setting of SW3 and SW4 is

Even Smarter Switching

The Cycfi guitar will have an on-board microcontroller (embedded microprocessor). We can incorporate an even more smarter and more user friendly switching scheme. Under the hood, we will be using low-power latching relays for each of the switches and have these relays under the microcontroller’s control. I’m pretty sure that previous statement will raise more questions. We’ll get to that soon. Cya!

Next: Bamboo Preparation (part 1)

This is an installment to last week’s Perfect Switching article. Again, let me warn you that this page assumes you know a little bit of electrical wiring and reading basic schematic diagrams. If you don’t know what “parallel” or “series” wiring means, this page will provide you with some basics: http://www.1728.com/guitar.htm.

Our goal is to devise a way to optimally utilize the 3 pickup configuration in order to have the widest sonic range possible. The basic Fender Strat switching gives you 5 possibilities. Brian May’s Red Special offers 7 possibilities (not including phase switching). The Strat pickups are wired in parallel, while the Red Special pickups are connected in series.

Best of Both Worlds

It is possible to have more pickup configurations by allowing both series and parallel wiring. We are already accustomed to parallel wiring since most electric guitars are wired that way. Series wiring, on the other hand, gives you a more powerful (“hotter”) signal that easily overdrives the amp. This is good for lead playing. The tonal quality of series wired pickups compared to parallel is radically different due to various factors, most essentially, shifts in the combined pickups’ resonant frequencies when the total pickup inductance is shifted up (series) or down (parallel). To give you an idea how different the total inductances are, given 3 identical pickups each with 10mh inductance:

• The total inductance when wired in series is 30mh: (10mh + 10mh + 10mh).
• The combined inductance when wired in parallel is 3mh:  1 / ((1 / 10mh) + (1 / 10mh) + (1 / 10mh))

With series wiring, the resonant frequency is shifted down while the power is increased.

Basic Building Block

The schematics presented in these pages are 100% original and has been prototyped and fully tested. You are free to copy the ideas presented here subject to the MIT license.

Let’s start with a 2 pickup configuration. This will be our basic building block that can be extended to 3, 4 or even more pickups. With 2 pickups, you have these possible permutations:

1. B
2. A
3. A | B
4. A + B

(See my previous article to understand the notation I am using)

To get these combinations, you need two DPDT switches. Here’s the basic schematic:

There’s really no on or off settings here. All switch settings will produce an output. Instead of on-or-off, let’s think in boolean: 0 or 1. 0 (zero) means that the switch is in its “left” position and 1 (one) means that the switch is in its “right” position.

Here’s the switching table:

There are different ways to achieve the same set of combinations. A previous version of this article employed a simpler wiring scheme. What’s unique about this updated schematic is that you have one switch (SW2) to control the choice of using one pickup (A or B) or two pickups (A and B). SW1 chooses between A or B when SW2 is in the one-pickup setting. The same switch (SW1) doubles as the series-parallel switch when SW2 is in the two-pickup setting.

The following illustrations show the signal flow for each of the 4 switch settings.

1. Pickup B only

   

2. Pickup A only

   

3. A and B in parallel

   

4. A and B in series

   

3 Pickup Configuration

With 3 pickups, you can simply use the same schematic as above and insert that into either the left box (A) or right box (B). It’s easier seen than said. Here’s the schematic:

With this setup, we have 13 possible combinations. The 3 pickups can be combined in series, parallel, series-parallel or parallel-series. Here’s the list of usable permutations:

1. C
2. B
3. B | C
4. B + C
5. A
6. A | C
7. A | B
8. A | B | C
9. A | (B + C)
10. A + C
11. A + B
12. A + (B | C)
13. A + B + C

Here’s the switching table. Note that we’ve introduced a new “don’t care” symbol: ‘x’. Where there’s an ‘x’, the switch’s position does not matter.

Ok, well, there you go. We now have a whole set of pickup combinations to choose from. With 4 switches, we are able to choose from all possible series/parallel pickup combinations. And we haven’t even added phase-switching yet, which, as mentioned in the first part of this article series, gives you a thin, squawky sound that is only occasionally useful.

Stay tuned for the third part that will conclude this series…

Next: Perfect Switching (part 3)

I am tired of the same old Fender Strat or Gibson wiring. Go to a music store and chances are, with a very few exceptions, you’ll see electric guitars wired either the Fender Strat way (5-way switch) or the Gibson Les Paul way (3-way switch). I want to be adventurous and explore new wiring configurations. I’ll be exploring alternative switching configurations for the Cycfi guitar.

Before I begin, let me warn you that this page assumes you know a little bit of electrical wiring and reading basic schematic diagrams. If you don’t know what “parallel” or “series” wiring means, this page will provide you with some basics: http://www.1728.com/guitar.htm.

I will be using this simple notation for brevity:

• Neck pickup: A
• Middle pickup: B
• Bridge pickup: C
• x | y: Parallel wiring
• x + y: Series wiring
• ‘x: x inverted phase

Examples:

A | C reads as: Neck and Bridge pickups wired in parallel
A + ‘B reads as: Neck and middle pickups wired in series with middle pickup connected in reverse (inverted phase).

Standard Switching

Your standard 5-way Fender Stratocaster switch connects one or two of your 3 pickups to the output with these configurations below:

1. A
2. A | B
3. B
4. B | C
5. C

With only two pickups (neck and bridge), you have only three options with the standard Gibson Les Paul switching:

1. A
2. A | C
3. C

Red Special

Strat and Les Paul pickups are wired in parallel. That is typical. Most electric guitars out there, with a few exceptions, are wired in parallel. One peculiar exception, and one that I am very fond of, is Brian May’s (of Queen) Red Special that he and his father built. Brian May is my inspiration. He is the very reason why I started building guitars in the first place. I love the thought of having my own unique signature sound that no one else will ever have. Contrary to norm, the Red Special pickups are wired in series. Also, instead of having a single switch, the Red Special has six! Three switches for pickup selection and three more for phase switching (out of phase switching gives you a thinner, squawky  sound since some frequencies cancel out each other). Like the Strat, the Red Special has three pickups. With the three pickup switches, you have all possible permutations:

1. A
2. A + B
3. B
4. B + C
5. C
6. A + C
7. A + B + C

Strat folks, you are missing the last two pickup configurations! (Aside: A friend of mine has a unique Strat model equipped with three pickup switches like Brian’s, but that model is very rare).

Now, if you add the Brian’s phase-switching into the picture, you have a lot more options. I list all the options below, removing redundancies (for example, A (neck pickup alone), is sonically equivalent to its inverse ‘A (neck pickup reverse wired)). I also removed the all-off combination. Here’s the list:

1. A
2. B
3. C
4. A + B
5. ‘A + B
6. A + C
7. ‘A + C
8. B + C
9. ‘B + C
10. A + B + C
11. ‘A + B + C
12. A + ‘B + C
13. A + B + ‘C

Brain May’s Red Special indeed gives you a fuller repertoire of sounds. There are a lot of redundancies though. If you consider the number of switches (there are 6), then the possible permutations would be 2⁶ or 64. Yet, in the list above, you see that there are only 13 unique timbres. The rest are duplicates.

Why?

1) A reverse phased pickup only affects the sound in combination with at least one more pickup connected normally (in-phase). The out of phase pickup will cancel some frequencies of the other pickup(s). You will not notice any difference in timbre when you invert the phase of a single pickup. Example:

‘A = A

2) Two pickups inverse-phased will likewise sound the same as its normal counterparts. Example:

‘A + ‘B = A + B

3) Two pickups inverse-phased plus another normally wired pickup will sound the same as the first two pickups normally wired plus the third inverse-phased. Example:

‘A + ‘B + C = A + B + ‘C

In short, the phase switching is only effective one switch at a time and only when two or three pickups are active.

Thirteen possible timbral options is a lot and offers a vastly superior sound repertoire. However, settings that involve phase reversal give you a thin, squawky sound that is only useful occasionally.

Can we do better? You bet!

Next: Perfect Switching (part 2)