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 where no amount of cleaning has brought them back to life. 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 and would I see any improvement? 

Guitar wiring

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 hunting is a slippery slope indeed, 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! As we deep dive into these details though, it would be easy to fall victim to tone related snake oil, vintage mystique or typical buzz words so I'm going to do my very best to stay away from all of that. There has been too many forum arguments already, I don't intend to add to that! I instead intend to focus on the actual specs and facts for you. I do however totally agree in the viewpoint that there are certainly very good reasons why so many place 'golden era' guitars on a pedestal. Those components stand the test of time, helping the instruments they're fitted to sound so great to this day. But I do personally feel that comes down to the details I will cover below, some simple rules of good build quality & tight tolerances. No mojo, no mystique, no snake oil! 

Replacing a pot or a tone cap won't necessarily transform your tone, it ultimately depends on the spec of components you already have installed in your guitar. So I would recommend investigating what you currently have, what the pot and cap specs are, that will give you a solid baseline of reference here.

If it's a USA built instrument for example chances are you will already have some pretty darned good quality components in there. Or you'd certainly hope so! Sadly it isn't always the case for USA production instruments, so a little investigation can go a long way. Swapping out components could well be a like-for-like situation for you though, so if you're looking for changes to your tone then your time and attention may be better off invested in understanding those specs, values etc and seeing if a revision of those values will help dial in your perfect sound to suit your ear.

If you have a far east built guitar, a Squier or Epiphone for example, then there is a very good chance they have been made using lower quality, broader tolerance components. I'll chat below more about tolerances and why that matters but to give a taster of what's to come, but to quickly summarise; A pot may be stamped 250k, but lower quality items may have a wide tolerance, 20% or more for example meaning the actual reading from the pot could be anywhere in the range of 200-300k. This could well be the component causing you a muddy tone, or ice pick highs. So many players over the years must have jumped straight to a pickup swap to improve there tone, but there is definitely room for improvement and/or refinement from your wiring too, it may even save you a few quid in the process. Tighter tolerance pots can be as little as 5%, providing you with a more accurate reading of it's stamped value, and a much more predictable tone/function which for me, is what this is all about. Once you have a good understanding of specs, you can spend your money more wisely, invest your time more wisely into improving your guitar tone. And the way I look at it, if you upgrade your wiring, and still feel the existing pickups don't capture what you want to hear. Then at least when you drop a nice new set of pickups into the guitar, your nice quality wiring will be getting the very best from them!

So! Let's dive in, and look at each area of guitar wiring (pickups aside). What they are, what to look out for and why changing them could improve your guitar.

Home of Tone Pre-Wired Harnesses

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. Fixed resistors and capacitors can achieve changes in sound, but what better than being able to refine it all with ease, that's where variable resistors are so helpful and that 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. There are of course a huge range of pots you can fit to a guitar, which as a result means there is also a broad range in quality available and for me if you're reading this with the intent to upgrade or improve your guitar then I want to look at the best available and why they are considered to be the best too.

The way I see quality pots, and quality guitar wiring components in general for that matter, is that they allow for improved functionality/control-ability that better suits your playing style. They help your pickups operate to their full potential and ultimately, help your guitar sound it's best when amplified too. For me, that starts with the quality of pots you choose to install. Also, even premium pots aren't exactly an expensive item, for £5-10 each you can purchase the best quality items available. So let's face it, 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 first of all. CTS are perhaps the most commonly used and well known guitar and bass potentiometer manufacturer, and for good reason. They do however manufacture a pretty broad selection of pots, varying in construction quality and tolerances. So they're not all are the same I'm afraid, and it isn't quite as simple as saying 'CTS are the best', but I certainly do consider specific variants by CTS the best available. Specifically, I feel their '450' premium range are just that.

The 450 CTS series specs include sturdy casings, brass shafts, bakelite plate, carbon graphite contact patch & the solid connections are second to none. Perhaps most importantly, they are precision made by a company who have been doing so for a very long time. Production of their components in the USA moved to Taiwan in the late 1960s, and quality has remained seeing their pots being used by high end guitar makers for decades. There are a few other popular makers of pots for guitars, such as Dunlop, Bourns & Alpha to name a couple, Bourns a popular quality alternative to CTS, but for me CTS 450 series in particular 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 so it might seem a bit confusing when choosing a replacement. Certainly don't let a store lead you to believe it's a one size fits all scenario, as there are premium, and standard series of CTS. Both with differing construction and tolerances. So if you want to ensure you're buying their best available, traditional and nicest construction and tightest tolerances, then you'll want to look out for the 450 series in particular. 
There are also fully sealed pots, produced by the likes of Bourns and Dunlop. These in theory will yield a much improved lifespan without maintenance/cleaning due to the sealed casings protecting the inner workings of the part. These are usually the most expensive pots available, ranging from £15 and above. Choice is limited though sadly, so you might struggle to source them, or find that there is limited selection of values. But the usual single coil or humbucker equipped guitars will be catered for with 250k and 500k options. 

Turning Torque - There are a number of well known guitar parts suppliers that have commissioned CTS to produce their own 'custom' spec of pot, and each may have chosen specs that differ from another companies preferences. If a company is in a position to commission their own range of pots, the benefits don't stop at just a bit of branding stamped into the casing. They can choose from a range of production specifications, one of those custom options will be the pots turning torque, or how stiff/loose the pot feels to turn. Which you prefer is totally up to you, I have had customers over the years much prefer their pots to turn quite freely, providing them with easy, fast swells for example. Eddie Van Halen was perhaps one of the famous advocates of a 'fast' pot, even seeing a EVH 'Low Friction' pot being commissioned to his specs by what I believe to be Bourns. Whereas other players favour very precise adjustment and a stiffer turning torque. I must say, the latter is perhaps the most popular as it's often seen that a loose pot feels 'cheap', but this isn't always the case, you can certainly obtain a high quality 450 series premium CTS pot with a looser turn feel, it may just simply be down to the turning torque they have been spec'd to. Examples of low friction premium CTS 450 pots include those commissioned by Emerson USA and Tube Amp Doctor in Germany. 

Taper - This is perhaps the trickier field to navigate I'm afraid, so I'll start simple and build up, 0 to 11! 

There are two main taper pots used in guitar wiring, Linear, & Logarithmic (Audio). You may even find a mixture of the two in your guitar depending on when and where it was made, I'll get into why in a moment. The human ear hears in a logarithmic manner, so the way you perceive incremental changes through a seep on volume or tone means you're not likely to be sensitive to when sound is changing in an even/linear progression. 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 of the rotation? This was more than likely a linear pot in action. 
Why is this? Well if you looked at the readings of a linear variable resistor (pot) 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 changes made. That is why logarithmic pots were designed, nicknamed 'audio' taper due to their intended use.
Ultimately, which you prefer to use is the player's individual preference. There is no true right or wrong here, but in most applications an audio taper 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 on hand 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. Some pedals respond so well to how you adjust your on guitar controls too so it can be a rewarding experience. So I feel that's why a quality logarithmic audio taper pot is an incredibly important component in the electric guitar. 

BUT! I can't stop there I'm afraid, as much as it can overwhelm the decisions, I figured if you've reached this far then you're keen on the finer details of all of this! There are actually multiple logarithmic taper types/patterns too. In all honesty, you seldom see this kind of detailed spec info advertised by suppliers. Unless you are ordering the pots from a specialist in the field, you'll most likely just see a pot from a parts shop listed as either audio or linear tapers. This unfortunately won't tell you everything about how the audio taper pot will respond through it's turn/taper. CTS for example in their 450 series offer 7 different audio taper options, each will respond slightly differently and appeal to players in different ways. You'll see this described as a % or with a letter signifying which production spec it has, 'H' or 'J' taper for example, and what that is telling you is what reading it would have at half turn. Linear would be the equivalent of 50% taper, the reading of a 500k linear taper pot at the halfway turn point would be 50%, so 250k, seeing it on a graph it would be a straight line diagonally across the graph as mentioned previously. Then the audio tapers would have a more gradual curvature, so the CTS B taper of 15% means that at the halfway turn point it would give a reading of 15% of it's value. This might sound like it's not useful at all, but bare in mind how our ears respond, in a logarithmic way. In my humble experience, the 15% B taper spec has proved to be a very popular taper and one I have used in wiring kits for a number of years via the 'True Vintage Taper' and also more recently, the Six String Supplies custom 450 series CTS pots. Other specs include 'C' 5% (Seldom seen to be honest), 'A' 10% taper (a spec I've most commonly come across used on the standard, non 450 CTS range), 'BD' 20%, 'H' 25% and 'J' 30% taper, the latter of which offering a player some finer adjustment in the lower range of the sweep. 
As I say, not all parts retailers will tell you, or know either, which taper spec the pots they have are. But specialists likely will, I certainly do my best to provide the information in each product listings and know of other respected parts/wiring specialists that do this also. If it helps, the Six String Supplies 'SSSP' series pots I stock have the 15% 'B' taper, along with the firmer turning torque feel. And the 'Tube Amp Doctor TAD' series pots I also stock have the 30% 'J' taper, along with the easier/faster low turning torque feel. So hopefully that will give you a nice choice between styles. 

Tolerances & Resistance - There are a few pot values you'll likely encounter in guitars, most common being 250k, 500k & 1 Meg. In most cases, single coil pickups are bright and clear in tonal character as a result of their design, meaning the general consensus has been to pair them with 250k pots. Whereas humbucker pickups can be naturally darker in tone, and pairing them with 500k helps get the best from them. 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. 

So, 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 premium CTS 450 series pot like the 'SSSP', 'TAD' or 'TVT' versions for example featuring a stated +/-10% tolerance will be accurately rated at above or below 10% of 250k. In all honesty though, in my experience these top of the range CTS pots actually end up being tighter tolerance than that upon testing, 5-7% for example. But they're stated to be +/-10% tolerance. 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.
Players like Eric Johnson are renowned for deep diving into a parts tub to find a pot value better suited to their requirements, so having a pot rated 260k when you see it being stamped 250k isn't necessarily the end of the world, it will just help predict how it will sound compared to another pot. Or one with a much broader tolerance. 
Some low quality or lower tolerance pots can creep wildly away from the ratings stated on it, you'd be surprised! I've removed some factory installed standard series CTS pots from US and MIM Fender guitars for example, that read a lot broader. Standard series CTS pots tend to be around 20% +/-. Where you could find 250k stamped pots reading closer to 200k, 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 your 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!

Guitar wiring

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. I've lifted pickguards and control plates on vintage instruments equipped with these very same spec switches, a quick clean with contact cleaner and they're working as good as new. That's a good sign of a quality switch, the new ones are no different in my humble opinion and work great. 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. 

On far east built, more budget instruments, you will often see PCB or enclosed switches. These aren't neccesarily bad, and I don't think there will be a negative impact on tone as a result of using one. BUT! I have lost count of the amount of cheaper switches I have to replace here for customers. Whereas I seldom, if at all, need to replace a CRL or Switchcraft pickup selector switch on customer guitars. That tells me all I need to know on this subject really. 

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! 
Budget jack sockets I have come across have had plastic housings and flimsy connections, these without doubt fail prematurely. A high quality jack socket like a Switchcraft or Pure Tone item retail around £5, so yes you can find jack sockets cheaper, but you'll likely need to replace it again soon whereas those quality items will last for years to come when correctly installed and maintained. It's a no brainer for me, solid connection results in more reliable use. 

Guitar wiring

Those early Fender and Gibson guitars we all know and love were wired at the original factories with a cloth covered 'push back' wire, as factories looked to cut production costs we saw more plastic coated, thinner gauge wires used and in most cases, these have remained to modern day production. Particularly on budget instruments. There can be absolutely nothing wrong with plastic coated wire, I'm not cork sniffing here! 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 in contrast, 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 some sort of recognition! As it is a hair splitting detail, but I wanted to discuss wire here and perhaps why 22AWG is the 'go-to' gauge. Ultimately thinner gauge wire can be flimsy, resulting in bad connections between components, they can be easily crushed and damaged. Will using a 26AWG wire sound any worse than a guitar with 22AWG, well, I'd likely be hard pushed to tell, but I would personally prefer to use 22AWG wire, be it plastic coated or cloth covered, as it is sturdier and more reliable for your connections. I use it everyday, on every harness build and I would say, every repair job too. 

Guitar wiring

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. Type of capacitor is where the arguements lie, so perhaps let your ears decide, I know I have and know which detail I am most interested in when choosing a tone cap.

Voltage - 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. So no real need to get hung up about the voltage of a tone cap, but what I will say is higher voltage capacitors tend to have larger casings. So if space is key, your guitar has a tight control cavity for example, then aim for something like a 50v or 100v spec, those will more than likely have smalling casings and be easier to fit in your guitar. Farads, however will effect the tonal response and I'll get onto that momentarily.

Types of cap - 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 difference. 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, and your ears are what matter to you.

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. 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. 

Value - 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 0.047uF capacitor would produce a perceived bassier tone than a 0.015uF value capacitor would. Which is why value choice can play an important role in dialing 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 single coils and humbuckers alike, 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, P90s and with single coils too, with a .015uF sometimes a popular choice for darker sounding neck humbucker pickups. A .047uF is used primarily for single coils only, I'll seldom see this paired with a humbucker for example. 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.

Tolerance - Again, tolerance is really important here. Most capacitors these days are produced within a very 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 or Paper in Oil 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.

Build quality - 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 and other repairers 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. 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.

Overall summary
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, predictably! 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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Alex Oliver

Alex Oliver said:

This makes more sense to me than those forums, manufacturers, vendors etc who seem to ignore HOW we play. I think I can make some informed decisions now on how to fix my V100 (Vintage brand Les Paul sort of form).

Despite being new the CT log pots crackle, squeal and hump in the middle – which spoils my violining.

Fitting Alnico IV magnets did the trick tone wise. Just for the record I ditched my COSM multi FX and went back to individual pedals with gratifying results (for a feedback using 30 watt digital amp user).

Also James

Also James said:

You say " you ideally want your wiring AWG to be the same or greater than the guitar’s pickup wire AWG "

Are you saying you should have a higher NUMBER AWG ..- ie: 28AWG
OR do you mean a larger thickness.. -ie: 16AWG

James Gascoigne

James Gascoigne said:

Thanks for reading :) I say ‘greater’ mainly because some cheaper pickups use very thin gauge wire, or some pickups are made with with 4 conductor wire which has multi strand thin gauge wire, perhaps 24 or 26awg for example. So one those examples I would want to use the same or thicker, like the industry standard 22AWG.
With AWG, the thicker the wire the lower the number. But I would be VERY surprised to see anything thicker than 22AWG wire used, anything thicker would be excessive. So the 28AWG you mentioned would be very thin, and I personally wouldn’t use that to wire a guitar as it would be a thinner gauge than what is likely to have been used on the pickup hook up wires. And 16AWG would be very thick, and again, massive overkill to use within a guitar as no pickup hookup wires would be done with something as thick as that, I’d be very surprised if there was anyway!

Gary Cuthbert

Gary Cuthbert said:

A great and informative read. Thank you. Now if I can just figure out how to get rid of the piercing highs without muddying the lows.

James Gascoigne

James Gascoigne said:

Hi Gary, thanks for reading the article and the kind words.
What guitar is it, and what pickup combination does it have? What are the existing electronic component specs, EG pot and cap value etc?

Patrick Flynn

Patrick Flynn said:

Very well written and easy to understand information for someone like me who identifies with the Guitar. I never became the player/tech I had always dreamed about. In the time it took to read your article, I just increased my overall knowledge of the beloved electric guitar. It has me thinking now.🎸


Terry said:

Excellent article, James… really helpful and now for the first time in 60 years I have a better understanding of wires and AWG. Cheers, Terry

Mike Dell

Mike Dell said:

Such a great article. I learned far more here than the combined past 3 weeks of searching forums regarding changing wiring harnesses. Thank you.


petar said:


I’ve found cts 450 pots made for musiclily, they have though a different marking at the bottom compared to the one from the manufacturer (450g…). any thoughts on whether these made for musiclily are legit or not? thanks

James Philip Gascoigne

James Philip Gascoigne said:

Hi Petar,
I don’t have personal experience with Musiclily’s specific commissioned CTS pots, but I can say from experience of working with and stocking a wide variety of different CTS 450 pots they will definitely all have their own unique markings. Basically each company that comissions their own spec of CTS 450 pots will have the choice of what markings are on the casing. Whilst I can’t comment on whether the ones you have are legit or not, I can say that each company will definitely request their own markings. So one 450 series pot from one distributor will likely have different markings to another distributor.


Tony said:

Great article. Hopefully I have the info I need to gut my gtretsch electromatic jet, and put it back together

Jeff O

Jeff O said:

Is the wire used to wire up a guitar shielded, or non-shielded? Does it matter? I’m modding a squier affinity jazzmaster with P90s. This article has helped tremendously! Thanks!

James Gascoigne

James Gascoigne said:

Hi Jeff,
Generally speaking the wire used for at least the signal path in guitars is shielded, the exact shielding method various from manufacturer to manufacturer, for example some will just be plastic insulation, some will be wax impregnated cloth insulation/cover, some will have braided outer shielding over a cloth or plastic coating. It doesn’t HAVE to be and will work without it, but it is generally better practice to use shielded wire for quieter operation. Ground wires (so those between pot casings for example) really doesn’t need to be insulated.

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