I want to replace my guitar's wiring, would it make a difference?
Replacing, or in some cases, upgrading your guitar's wiring may be a matter of necessity if there are niggling faults like faulty switches or noisy pots perhaps. But you may also have considered replacing it as a way of improving or modifying the guitar too. So the big question is of course, would it make any difference/improvement?
That's ultimately what I'm hoping to address in this post I'm looking to touch on the various aspects of guitar wiring components, what to look for and why it would, or wouldn't positively help the guitar in question sound it's best. Tone is a slippery slope, we as guitarists & gear nerds too, find that we just can't help refining, modding and going deeper down into the rabbit hole of dialing in our perfect sound. If it makes us happy, and brings more inspiration from our instruments, then why not huh? I'd imagine that's one of the reasons you're here reading this article too!
Sure, a guitar pickup can be wired directly to the output jack socket. But more often than not, guitarists will desire some tonal, and volume adjustment at their fingertips instead. Which is where your potentiometers, pots for short, come into play. Installed in our guitar, your volume and tone pots regulate resistance of the flow of current from the pickups, by regulating the resistance to the flow. They have a carbon graphite contact patch, or path, to achieve this variable resistance which you adjust by turning your control knobs.
The way I see quality pots, and quality guitar wiring components in general for that matter, is that it allows your pickups to operate to their full potential and ultimately, your guitar sound it's best when amplified. For me, that starts with the quality of pots you choose to install. Also, pots aren't exactly an expensive item, for £5-6 each you can purchase the best available quality item, so really, you may as well put the best quality item in your guitar and with care and maintenance, there's no reason why it wouldn't last a very long time too.
Build quality - Let's face it, you don't want to be replacing components regularly, so build quality is worth your consideration. CTS are perhaps the most commonly used and well known brand, and for good reason. CTS's sturdy casings, brass shafts, bakelite plate, carbon graphite contact patch & solid connections are second to none, and importantly are precision made by a company who have been doing so for a long long time. There are many makers of pots, such as Bourns & Alpha to name a couple, but for me CTS have proved to be the most reliable items available and my pot of choice when making my wiring harnesses. They're often considered industry standard, but they make many, many variations and not all are as good as some. I've seen some lower quality series' of CTS pots that have been wildly inconsistent, which I'll get to in the next points. But chances are, if you've bought a CTS pot to fit into your guitar, it'll be a well made item by a well established and reliable company.
You may also notice that most CTS pots have a firmer feel when turning, (some custom made versions like the Emerson CTS pots have a light turning feel though) whereas a bourns pot moves incredibly freely. This might help with your choice of pot for your guitar depending on whether you like a firmer, or looser adjustment on the controls.
Taper - There are two main types of pots used in guitar wiring, Linear, or Logarithmic (Audio). You may even find a mixture of the two in your guitar too. The human ear hears in a logarithmic manner, so the way you perceive the effect on volume, or tone depending on it's function, means you're not likely to be sensitive to when sound is changing in an even/linear progression, be it high to low volume or high to low frequencies. Have you owned a guitar that when you adjust the volume pot, it sounded like nothing was changing, then suddenly a rise or fall in volume right at the end? This was more than likely a linear pot in action. Why is this? Well if you looked at the readings on a graph, for linear you'd see a completely straight line diagonally upwards which at first would sound like that's perfect right? Not quite, our human ear isn't so keen on that, and we actually only perceive a small percentage of the incremental change made so it appears like nothing is happening when adjusting a linear pot right up until the last moment.
Ultimately, which you prefer to use is the player's individual preference. There is no true right or wrong here, but I find that a quality logarithmic pot in both volume and tone positions offers a player more scope for a more intuitive playing experience, if using a quality pot that is of course! A guitar's volume and tone pot can bring out so many great sounds from your rig, it offers versatility to your sound, and I personally love pushing an amp hard and finding those sweet spots on the guitar's controls to really capture a great tone. So I feel that's why a quality logarithmic audio taper pot is an incredibly important component in the electric guitar.
Tolerances & Resistance - There are a few pot values you'll likely encounter in guitars, most commonly 250k, 500k & 1 Meg. Although if you bought a Gibson after the 70s you may have encountered 300k pots too, which aren't as common these days in Gibson guitars as many owners complained of muddy sounding pickups. So as you can see, choosing the right value of pot for your guitar's pickups is an important point.
In most cases, single coil pickups are bright and clear in tonal character meaning the general consensus has been to pair them with 250k pots. Whereas humbucker pickups can be naturally darker in tone, meaning you would want to aid their clarity by pairing them with 500k pots. But you don't have to stick to these conventions, the guitar you play has to help create the sound you like, but these are the key starting points to finding the right value pot for your guitar.
What is tolerance and why does it matter? The tolerance refers to how accurate you can expect the pots resistance to be. So if it's a 250k stamped pot, then a CTS 'TVT' brand pot for example featuring a stated +/-10% tolerance will be accurately rated at above or below 10% of 250k. So by default, you shouldn't find that when tested with a multi-meter, one of those pots would read below 225k or above 275k. A pot with a tight tolerance, will provide you with a better idea of what sound to expect from the pickups.
Some low quality or lower tolerance pots can creep wildly away from the ratings stated on it, you'd be surprised! I've removed CTS pots from US and MIM Fender guitars for example, that were incredibly inaccurate. 250k stamped pots that were not even 200k, making it a +/-20% tolerance pot on that occasion and also in other cases past 300k. So, why does that matter? Well if we're referring to a single coil equipped guitar like a Stratocaster, they recommended a pot ohm value of 250k in both volume and tone positions. If a lower quality pot states 250k but actually reads much lower when tested, perhaps 200k like the above example, or even substantially higher, it could result it a muddy or shrill tone respectively. This is of course a generalization for the sake of example, but I have found even standard series CTS pots when tested read wildly different to what they should have been. Accuracy and tolerance is worth it, a pickup manufacturer sets out to design a certain model of pickup that will sound it's 'best' (obviously this is subjective), optimal is probably a better word, for a certain pot rating. If you're fitting a harness with tight tolerance, accurately rated pots then chances are you're going to be getting the best from your pickup set and it's going to be easier to know what sound/tone you expect to hear. That's the important bit for me.
In Summary - Look for well made, tight tolerance pots with a resistance value that will bring out the best in your guitar's pickups and provide you with adjust-ability, be it linear or logarithmic, that suits the way you play. But do please consider some routine care and attention to your pots. We change strings regularly, perhaps oil the fretboard or clean up the nut slots. Well you pots work hard, they're used regularly and over time can get a little dusty too. So don't be afraid to maintain them like you would any regularly used item. Some Mannol contact cleaner for example will work wonders in keeping the pots working optimally for a long time. I hope the information above helps you achieve all of those things!
Switches and jack sockets
For some players, flicking the pickup switch to change your sound is more common than adjusting your tone pots, and for certain, your jack socket will take the most abuse out of any component. So these are important items to consider when modifying your guitar wiring I feel to ensure they last well, and keep your signal path clear.
Switches - In a play-ability sense, you want a firm feeling, accurate switch and one that lasts well with regular use. I would happily recommend quality switches from the brands renowned for their years of producing reliable items to the guitar industry such as those from Switchcraft, Freeway, Oak Grigsby & CRL for example. I have used all of the brands noted here for many years, both personally and professionally and they prove to be a reliable item. No tonal magic or snake oil to be discussed here, obviously! Just a well made component that will last through regular use. But maintenance and care goes a long way, so perhaps consider opening up your guitar from time to time and cleaning out any dust that might have built up over the years and spraying the switches with a quality contact cleaner like Mannol for example. After all, you'd perhaps clean the fretboard and frets regularly, so it's worth thinking about the hidden, functional parts too.
Output Jacks - Importantly, you want a jack socket that doesn't fall apart or get crackly over the years of years, they take a lot of abuse after all! The most commonly found jack socket on a guitar is a 1/4", two connector female audio jack socket. The Switchcraft mono jack socket is an industry standard and a quality item to install, but in recent years I have been predominantly using a multi contact jack socket made by a company called 'Pure Tone'. Please forgive their brand name, as this isn't some tone transforming jack socket I don't think, I'm sure there are some graphs out there that show A/B improvements but let's not worry about that for now. For me, this is a common sense improvement of an old design which is great. It features 4 points of contact for the jack connector, two for the hot, two for ground. 100% greater surface area, giving it a firmer seat on the jack connector and a sturdier, more reliable connection which is a no brainer upgrade in my opinion. They're well made, just as easy to fit and provide your guitar lead with a firmer and more reliable connection. Win win!
Those early Fender and Gibson guitars we all know and love were wired at the original factories with a cloth covered 'push back' wire, whereas as some modern factories, far east predominantly use modern standard plastic coated wire today. But the important detail is the 'AWG', or American Wire Gauge. For AWG, the lower the number, the thicker the wire. Widely used in the guitar world for optimal results, is 22AWG wire. This is mainly because you ideally want your wiring AWG to be the same or greater than the guitar's pickup wire AWG and in most cases pickup manufacturer's use 22AWG. So it would be overkill to use anything thicker than 22AWG, simply because it is very unlikely a guitar's pickups have been made with anything thicker than 22AWG. But you could have pickups that have been wired with thin plastic coated hookup wires, perhaps if it is a cheaper mass produced pickup or one with 4 conductor wiring which often is around 24AWG so you could use the same 24AWG for example or thicker (22AWG for example) to wire the guitar electronics for optimal results.
I would go into detail on this, but THIS site has some superb facts about AWG and a lot more than I would care to delve into! So if you'd like to find out more I'd recommend a read of! So back to the cloth/plastic thing. Personally, I find the 'push back' cloth wire is much easier and tidier to work with and I fully hold my hands up to saying it looks much better too if you're installing in iconic 50s designed instruments like a Telecaster or a Les Paul perhaps. A nice period correct detail. I always use this for any guitar wiring, the results are always great and it's a pleasure to wire up with. I personally use Gavitt USA 22AWG cloth covered wire, which is stranded pre-tinned copper wire. It's reliable, easy to work with and a quality wire to use in guitars. In a real world test, if you can hear the difference between different AWG of wire in a guitar circuit, then you deserve recognition! As it is a hair splitting detail, but I wanted to discuss wire here and perhaps why 22AWG is the 'go-to' gauge.
Get your corks ready to sniff, yup, we're talking tone capacitors. If you're a member of any guitar forum, I'm sure you've encountered many a thread about this too. Naturally there's going to be an awful lot of discussion about this subject, if that's your thing then no harm in it at all, but I'm going to keep it as civilized as I can sticking to facts and my findings/experiences. Ultimately, the key detail to look at is the value rather than type I think, value will provide the differences most ears will notice the differences of.
Capacitors are used as part of our guitar's tone control. Capacitors are measured by farads, and each are rated at a specific farad and a level of voltage. Now, voltage doesn't matter too much when it comes to guitar circuits, your guitar doesn't need anything over 100v ultimately, but there is no harm in installing a 500v or 600v if needs be or it's what you have to hand to install. In fact, I've found most tone capacitors for guitar circuits are rated around that voltage anyway. Farads, however will effect the tonal response and I'll get onto that momentarily.
There are also different types of capacitor and perhaps the most common types found in a guitar circuit are ceramic, polypropylene film, polyester (mylar) film and paper in oil. I have spent a lot of time trying different types, all as a means of researching the best quality for my harnesses, learn more first hand about guitar wiring rather than getting caught up in forum discussion on the subject. Hand on heart? I really struggled to notice a difference between the types, or rather to an extent where I could say A was better than B. I've A/B'd between types on the same guitar and as long as they were the same value, I personally couldn't tell the different. But alter the capacitor's value IE between .022uF or .047uF for example and that should noticeable and where I think the attention should lie. That's the detail that matters the most as ultimately that is going to tell you most about how a capacitor will sound in a guitar. Sure, paper in oil caps sound great, but for the most part, quality polypropylene film ones do too! So I wouldn't split too many hairs over choosing a 'type' of capacitor unless your budget allows you to spend more on one and you get enjoyment from doing so. Again, if you enjoy experimenting and ultimately want a pricier paper in oil capacitor, who's to tell you not to? The internet is full of naysayers! So if your budget allows and you enjoy doing so, then go for it and see what difference you notice! I found the process interesting for sure.
One thing to ask yourself, is how often you adjust your guitar's tone pot. If you seldom touch it, or never adjust it at all! Then I really wouldn't worry about choosing a fancy tone capacitor, a simple and cost effect item such as the trusty Orange Drop will be more than adequate and provide great response from your pickups and controls.
Perhaps the most popular choice of capacitor, (and the most popular for cork sniffing discussions on forums) is a paper in oil capacitor. Again, no real right or wrong here, if your budget allows you to splash out on capacitor choices and you get enjoyment from doing so, no one can tell you not too, certainly not me! I too have experimented with very high end capacitors, as well as offering them as custom upgrade options over the years, but I've decided now to keep it more simple as it can be overwhelming to choose between them all, that is if cost alone doesn't make the decision for you.
So, the main detail (as far as I'm concerned now anyway) is the value, honestly there is no right or wrong here really, it's down to personal preferences and different values will have different effects on the sound produced. So why does value affect the perceived sound? Treble frequencies pass through a capacitor easier than some mid and perhaps more importantly, bass frequencies. So a .047uF capacitor would produce a perceived bassier tone than a .015uF value capacitor would. Which is why value choice can play an important role in dialling in your personally preferred sound or versatility of your pickups installed. You can technically wire in a 'fixed' capacitor into a guitar's circuit but more often than not, it is attached via a variable resistor...your tone pot!
So, how would you go about choosing a cap value?
By design, a single coil is usually a brighter sounding pickup than a humbucker, so you may commonly find .047uF capacitors in guitars with single coils to really tame some of those high frequencies. Whereas a guitar with a humbucker installed will likely have a capacitor installed that would allow a little more of those high frequencies into the circuit helping retain some clarity to the tone. Again, there really is no 'set in stone' value to use, feel free to experiment and find something that suits what you are after or the pickup set itself. As a general rule, a .022uF offers a great overall response, it works great with humbuckers, but it can still work well with single coils and for this reason I offer this value as standard across my entire harness range.
But some players sometimes use a .015uF with a neck position humbucker to further help with some high frequency clarity, particularly useful if you have a darker neck humbucker tone and want to try and liven it up a little more, and in the opposite end of the scale, Fender even used 0.1uF capacitors in some early Strats and P-Basses to really take hold of those high frequencies! From chatting with a few P-Bass players, this is quite popular to achieve a tone like Pino Palladino's iconic sound.
I've also found that a .022uF capacitor will dump the high frequencies to ground when you roll off the tone control in a little less drastic fashion than a .047uF does, so you'd perhaps notice a more prominent drop in treble when rolling a tone pot down which has a .047uF cap wired to it than you would if it was a .022uF.
This to me is an important detail to consider when choosing the right cap for you, referring back to the logarithmic audio taper pot, a gradual effect on treble frequencies and a more balanced control could be a very good thing right?
The general rule is .022uF for humbuckers and perhaps P90s, with a .015uF sometimes a popular choice for darker sounding neck humbucker pickups too, and a .047uF is used primarily for single coils. Looking back at the discussion regarding pot value and usual pickup characteristics, humbuckers a generally darker in tone, so if you use a tone capacitor that has a more dramatic effect on high end frequencies, that could result in loosing those much needed treble frequencies too quickly. So a more subtle management of those trebles are helpful for most players and the .022uF is great for this. This really isn't set in stone though, so perhaps consult your pickup manufacturers recommendations first. McNelly Pickups for example recommended .022uF for all of their models of pickup.
As a personal example, I have Teisco inspired Gold Foil pickups in my Millimetric Instruments MGS3. These are great with 500k pots as it brings the pickup to life, but the bridge pickup with 500k can be prone to being a touch on the harsh side, amp setting dependent of course. I experimented with a .022uF to begin with, my usual go to value, which was wonderful with the neck pickup but still allowed the bridge pickup to sound a little too bright at times, so I have settled with a .033uF value cap in the guitar now. A nice middle ground that still allows the neck pickup to breathe and retain clarity, but ever so slightly tames the bridge pickup without loosing it's sense of power from the high frequencies. What type of capacitor do I use though? I really didn't mind what I used, as long as it was a nice quality, tight tolerance item, which a trusty polypropylene film delivered on just fine for a low cost!
Again, tolerance is really important here. Most capacitors these days are produced within a tight tolerance, I've found it to be pretty darned rare to find a modern produced cap that isn't within a tight tolerance. Vintage caps on the other hand can sometimes provide challenges in that respect, so if you are heading down the vintage cap route, have your capacitor meter to hand to ensure what you're installing is what it is stated as, so you can better predict how it will actually function.
The only point I would make in regards to quality of construction of a capacitor, is that in my experience I have had more issues with faulty capacitors and lead outs breaking on paper in oil caps than I have hardy polypropylene film or polyester film caps. Maybe I've been un-lucky, but speaking to guitar makers etc it seems I'm not totally out on my own on this. For reliability, consistency and value for money, I tend to stick with polyester film caps when making and supplying my pre-wired guitar harnesses. I'd rather know that my harness will survive the journey via the courier, survive the install and last for years to come in my customer's guitar than worry about it failing on me. In testing, polyester film or even polypropylene caps have appeared to be the most reliable for me at least. All capacitors are susceptible to excessive heat though, so take care when installing your tone capacitors as to not overheat the solder joints.
I've tried to cover as many aspects of guitar wiring as I can here, and hopefully it will provide you with reassurance as to why quality guitar wiring components are important. But it is a bit wordy, granted, so apologies there! A lot of it may be old news to others, but I hope it helps in some way. I haven't written it to argue about details, I just wanted to put an article together sharing some of my experiences and findings. Speaking with people in the guitar world I admire, books I've read on the subject and importantly, my own experiments with guitars over the years. Truth is, if components on your guitar have failed, are un-reliable or you simple fancy upgrading your wiring, it is a really worthwhile and rewarding modification to carry out. Replacing parts with quality components, of reliable build quality and accurate tolerances and ratings will simply be the best for your guitar and bring out the best in your pickups. So I do personally feel upgrading your guitar's electronics is worth your while (depending what is in the guitar originally of course!). You may well also see a tonal improvement afterwards which each customer of mine has reported back after fitting one of our harnesses, which is lovely to hear. There's no magic, no mojo or snake oil here to achieving a responsive, great guitar tone. Just quality components doing their thing! I hope this article helps, I hope this article de-mystifies some of the discussion often had about some of these components, and comes across as I intended it to, an honest look at each aspect of guitar wiring and why it could make a difference.
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