Electronic Mods - Know Your Options Part 3

I've been mostly talking about versatility and adding options to your instrument (here and here), but what about making what you already have more usable. That volume pot that takes away the highs when you turned it down, or that rarely used tone pot, that either cuts too much highs or not enough. Thankfully this can all be altered to get you much closer to what you want.

First thing to keep in mind as for as pots go, values are the most important part of the equation, and the higher the pots value the more highs you have.

That's why 500k are usually the recommended value for humbuckers and 250k for single coils, but in all honesty there are no rules. If your humbuckers sound dull and lifeless, try a 1000k pot, much cheaper than buying new pickups and may solve the problem.

Potentiometers can be wired in a lot of ways, the most common ones are volume and tone pots. The volume pot shorts the pickups output to ground, reducing it's volume untill you can't hear it anymore. The tone pot is a high pass filter, and with the help of a capacitor, sends the high frequencies to ground, making the sound darker and deeper.

While some people love them and use them a lot I get a lot of requests about changing them, mostly the way they behave. So here are some mods and what they do:

Treble Bleed - There are many ways of doing this, and I find there isn't one that works for every guitar and everyone. You may have noticed that when you turn the volume on the guitar down, for example half way, to clean up the sound, your tone gets muffled, the highs go away, like if you messed with the tone pot. A treble bleed solves this problem, by bringing back some of those lost high frequencies. Depending on what you want, this mod can also be made to add highs as you turn the pot down, this is particularly useful you use the volume to go from overdriven tones to clean ones.

Improving The Sweep - In some cases your pots sweep can be very inconsistent. Nothing happens until you reach the end of the pots travel and you get no in between positions: from 10 to 3 nothing changes and then suddenly you are left with no highs (tone) or no sound (volume). This mod is made to correct that problem. It gives a large range with a usable sweep, I find especially useful in the tone pot.

Cap Change - Capacitors or caps for the tone pot come in a huge variety of sizes, materials, and values. Just like the pots let's focus on the value: the higher the value the more highs disappear when the pot hits 0. Usually your guitar will come either with a 0.047 (single coil) and 0.022 (humbucker). 

Find your tone pot unusable (especially on 0), change your cap. There a lot of values you can try, and they don't just affect the end of the pots sweep, but all of it. A smaller cap will give you a less extreme end, but more in between positions.

To help me and the clients make the choice and find the best cap for the guitar I built a tone cap tester (inside the box of an old fuzz pedal). It has a pot and a 6 position switch with selected caps and a bypass switch (to compare with the original sound).

Note: Both caps and pots have a tolerance, so it's not unusual for a 250k pot to actually measure 300k or 200k, this will change the way they sound and act. Keep that in mind when changing pots and caps, and measure them to make sure. 

Jay

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Electronic Mods - Know Your Options Part 2

In the first part we looked at mods we can perform to an individual pickup. In part two we'll talk about ways of wiring two or more pickups together.

Note: all of the these can be performed with single coils, humbuckers or the mods presented in part one.

Parallel - Most guitars come wired this way, just like the middle position on a Les Paul, or position 2 and 4 on a Strat. The two coils on the separate single coil pickups are wired together (if they are reverse wound/reverse polarity they will also cancel hum) but instead of adding the output of the two coils they cut the output. Let's look at your typical vintage style strat pickup, output wise they are usually in the 5k ohms when we wire two of them in parallel the resulting output is 2,5k ohms. The resulting tone is the beloved strat quack, a very clean, glassy tone.

Series - The opposite of the parallel wiring and not just electronically. Instead of a clean, trebly sound, wiring two pickups in series gives you a heavy, dense tone, much closer to a higher output humbucker, but more balanced. I especially like this mod on Jazz Basses, since it gives the hability to have something completly different to the stock sounds.

Brian May Red Specials pickups are wired in series, with switches for out of phase options.

In Phase - Remember how your typical guitar is wired in parallel in the middle positions? Well it's also wired in phase. Without going to much into the science behind it this means that the sound you hear is the summation of the two pickups.

Out of Phase - The opposite of the in phase explanation. The coils are "fighting" eachother and canceling equal frequencies, what you hear is the frequencies that don't get cancelled out.

This results in a weak and with very little bass, nasaly sound.

Probably the most well known user of the out of phase tone was Peter Green. You can wire any two pickups out of phase, altough I find it works best with humbucker and combination of neck and bridge pickups. To avoid a large volume drop you can wire the pickups in series and out of phase.

All theses mods can be made to be actived with a toggle switch or a push pull pot and can add a lot of versatility in your guitar, including some very uncommon tones.

Jay

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Electronic Mods - Know Your Options Part 1

In the previous post I mentioned some of the electronic mods that could be done to an instrument and I promised to look into them in the future.

Well welcome to the future! Altough depending on when you read this it could already be the past... freaky...

Let's start with the most common humbucker mods. Keep in mind that these mods require your humbucker to have four wires.

Note: Even though most humbuckers can be modified to have 4 conductor wires, this should only be done by an experienced tech.

Split Coil - A humbucker has two coils, and this mod "shuts off" one of them. In theory you now have a single coil, this also means that the typical single coil hum will be present.

As far as sound goes, let's just say that a single coil has a very different construction from a humbucker, so you might end up with a very thin, bright and weak tone. The end result is greatly influenced by the humbucker's design.

Variable Split Coil - This is one of my favourite mods. Especially nice for the folks who don't use the tone pot. Instead of "shutting off" one of the coils with a switch you can gradually turn the coil off. So you can have the full humbucker when the pot is on 10, only one coil active with the pot on 0. Between 0 and 10 will have one full coil and part of the other. Besides being very versatile you'll only get hum on 0.

Partial Split Coil - A cross between the the split coil and the variable split coil. Allows to choose between the full humbucker and one full coil and part of the other one. This allows to have 100% of a coil with 25% of the other one for example. Meaning you'll have a brigther tone, with less volume drop and no hum.

Coils Wired in Parallel - Most of your stock humbucker are wired in series. This means that the coils are adding to each other, you get more volume, more mids, more bass and less highs. By wiring than in parallel you'll lose some bass, but keep the mids and gain some highs. To me with a lot of humbuckers this gets much closer to the sound of a single coil than the split coil, with less volume loss and no hum. Different humbuckers will have very different results it's a hard mod to predict.

Coil Taping - This mod is often confused with split coil but it's something entirely different and is in fact not a humbucker mod, but a single coil mod. You'll need a special single coil to perform this mod. Seymour Duncan sells a couple of single coils that will allow you to do coil taps, like the Quarter Pound for Telecaster. Single coils that allow this mod will have three wires, the usual start and finish that will give you the full output single coil, and another one somewhere along the coil that will give you a second output reading. Let's say you have a high output single coil that measures 9k ohms (full output), and a third wire that will allow you to cut that output to a 5k ohms, that's coil taping. In the same pickup you can have the sound of a high output single coil and a vintage one. Works really well and gives a lot of versatility.

Next time will take a look of mods between two pickups (including connecting them in parallel or series, both in phase and out of phase) and mods for your tone and volume pots.

Jay

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