Custom Guitar Parts - Supercharged or 'Snake Oil'?

Bob Leggitt | Saturday, 19 November 2011
Custom guitar parts

Since the late ‘eighties I’ve seen myself as someone who’s obsessed with the sound, look and feel of his guitars, to the point where I’ve sometimes spent more on custom parts than on the instruments themselves. Small differences in tone do matter to me, but recently, whilst browsing the web, I saw a discussion about capacitors in guitars, and whether it was felt that different brands of the same microfarad value affected the tone differently. My first notion was to take my hat off to the marketing genius behind the concept. Whoever first managed to persuade us that their 0.5 microfarads were somehow perceptibly different from anyone else’s 0.5 microfarads, was clearly a being of higher intelligence. Then I remembered reading, many years back, about a well known guitarist detecting differences in the tone of his Strat, based on whether or not his jack plugs were gold plated… So, was there a 'snake oil' element to the custom parts industry, or were my ears merely too insensitive to appreciate some of the finer points of tone?…

Here's a look at some of the most common tone-focused customisations, along with my views on how much impact they're likely to have...


The component perhaps most obviously associated with revamping a guitar’s sound is a replacement pickup. There’s absolutely no question whatsoever that changes in the spec of the pickup will affect the output of the guitar. Small changes in spec will make a little difference. Big changes will make a big difference. Replacing a regular Strat single coil with an overwound Gibson-type humbucker will dramatically change the signal the guitar sends to the amp, and thus radically change the tone (and the volume). As with all tone-focused customisation, whilst you can get a rough idea of what a new pickup will do for your guitar, you’ll never know the exact result until the unit is fitted. The outcome is unreliable. You have to take a risk. That said, of all the pickup changes I’ve made, I’ve significantly preferred the replacement in the majority of cases, marginally preferred the replacement in a few cases, could tell no real difference in a couple of cases, and in one case, much preferred the original pickup.

I should say that the latter instance relates to the first pickup change I ever did, and the replacement pickup was a cheapie – certainly not a premium brand. Also, I tend to replace with similar design pickups (aiming for a higher quality version of the same basic sound), and not with something massively different. This increases the likelihood of a few occasions upon which things sound almost identical. For example, I might replace a Tokai vintage type Strat pickup with a Fender Custom Shop or Seymour Duncan vintage type Strat pickup. However, even under that kind of circumstance, most often, there’s an easily detectable change. And in my experience, products from reputable manufacturers usually do improve the guitar’s tone (often very considerably), provided you properly research what’s available and buy the model which matches your needs.


The maximum resistance of the potentiometer has an influence on the sound of the guitar. A 250K (vintage) type pot is less technically efficient than a 500K or 1Meg pot (1Meg is 1000K, by the way), but this isn’t necessarily a bad thing. If, for example, you’re using the pot in conjunction with a capacitor as a tone control, then a 1Meg value will give a sound truer to the pure tone of the pickup than a 250K value. Translated, this means that with a typical low-pass arrangement, a 1Meg pot will reproduce higher treble than a 250K pot, with the tone set to 10. If you want really zingy highs, you’ll prefer a 1Meg pot. If you find your guitar a bit trebly, a 250K tone control will limit the high frequencies slightly and perhaps prevent your instrument from sounding too brittle with the tone full up. The value of the pot does make a difference, and it’s not 'snake oil'. But two separate brands of pot, both of the same value, would only for me be an issue of which one is more durable, and perhaps the resistance ‘curve’ (how steadily the tone or volume is reduced) over the rotation of the knob. With values like for like, different brands don’t make any perceptible difference to the sound of the guitar. Not to me, anyway.


In my view, the only thing worth worrying about is the value, with a cursory nod to any tolerances, which will dictate the value’s accuracy. Changes in tone between two resistors or capacitors of equal value are negligible, and not sufficient to be detected in a normal, practical situation.


Changing the body or neck of a guitar is an expensive business, and is as great a gamble as any customisation could possibly be. The wood can dramatically affect the tone of the guitar. But the problem is it can do so for the worse as well as for the better. I would advise against changing the neck or body of the guitar in a bid to improve the tone, unless the original wood is very obviously of unacceptably low quality – a really grim-sounding piece of plywood, for instance. And even then I’d have reservations, given the cost of a new body.

True, plywood won’t age in the same way as solid wood, and I’d expect a guitar made, for example, from solid alder, to mature more successfully than one made from ply. But it can’t be said with any certainty that replacing a plywood body with a new solid wood body will give an instant improvement in tone. It’ll very likely change the tone, but whether you’ll prefer the new sound depends on your personal taste. Whilst the type and age of the wood has a fundamental influence on the tone of the guitar, replacing a body or a neck is just too ‘blind’ a decision to warrant the outlay for me. It would make far more sense to trade in your entire guitar on a new one (new to you, but not necessarily brand new, of course). At least that way you could ensure you really were getting a better sound and that your upgrade was going to be cost-effective.


Components such as the bridge, machine heads, etc. will have a bearing on the sound of the guitar. Anything which directly anchors the strings to the guitar is likely to influence the resonance, sound and/or sustain. The bridge/tailpiece combination in particular can have a marked effect, so it’s certainly true that changing some metal parts for alternative designs will make a significant difference. This needs careful research, though, and not all changes will be for the better. I'd recommend avoiding any modification which involves routing or drilling the guitar, as this is irreversible if you prefer the original parts and want to restore them.


A graphic equaliser may not be anywhere near as sexy as a flash new bridge, but it’s a hell of a lot more predictable when it comes to precision-manipulating a guitar sound. It does sometimes seem crazy to be spending a lot of cash on guitar parts which make little or no difference, when you can buy reliable tone-shaping equipment for less. Guitarists are notoriously insistent on having their tone sorted within the instrument though, and I’m no exception. But it can reach the point where common sense has to prevail over endless, never-quite-right modifications, and the final step in getting the perfect tone handed over to outboard gear.


Here’s a checklist of important things to look at before you decide your guitar needs customising…

Do you use the tone and volume controls on your guitar? It’s amazing the number of guitarists who want a “warmer and less trebly sound”, but have never considered reducing the treble via the guitar’s tone control. If you play a vintage type Strat, and the bridge pickup has no tone control, taking the volume down to 9 will mellow down the tone as well as reducing the volume slightly. Alternatively, you could simply connect the bridge pickup to one of the tone pots. It does make a Strat a lot more versatile. If you’re worried about losing too much output level, try moving the bridge pickup closer to the strings. I very often back the tone well off when using the bridge pickup on a Telecaster. Why buy a new, super-mellow/warm pickup when you can simply turn an existing knob on the instrument?

Have you tried heavier strings and/or a higher action? It depends on your style and tolerance as to whether or not this is an option, but it will make a BIG difference. Going up a gauge or two with your next string set and raising the action slightly is likely to improve the tone of your guitar a lot more than a pickup rewind, and even many full pickup replacements. It’ll add depth and bottom end to the sound and fill out the midrange in a very natural way. If your style depends on the strings not being too tight and hard to bend, you could always tune them down a semitone, like Hendrix did. Hendrix didn’t have DiMarzio and Seymour Duncan supplying him with better pickups. He used brand new stock CBS Strats. His great tone had nothing to do with custom parts or vintage instruments.

Exhaust all options on your FX unit and amp. Again, this is something that sits right under people’s noses, but they don’t necessarily experiment to the fullest extent. Some people whack the Bass, Middle and Treble up full on their amp, conclude that because the Bass is up full, they can’t get any more bottom end, and then start unscrewing their scratchplate. But the tone controls are interactive. Reducing the Treble and Middle will effectively give the tone more bass, provided you compensate with the volume. Try subtracting different elements of the tone as well as adding, and compensate with the volume if necessary. Revisit the tone-shaping on both your amp and your FX unit, and exhaust all options before you order new parts.

Have your pickups got covers? Pickup covers can change the tone of the guitar. If, for example, you have a Gibson type humbucker without a pickup cover, and you find the sound too bright, adding a pickup cover will remove some of the top end and round the tone a little. If you do have covers and the sound doesn’t have enough bite, removing them could be the only step you need take. Basically, any pickup cover which comes between the poles and the strings, or affects the magnetic field, will influence the sound. A Telecaster neck pickup cover is another typical example. However, plastic covers which don’t cover the pole-pieces, such as regular Strat pickup covers, won’t affect the tone.

Ultimately, whilst most of the custom parts designed to enhance tone will make a perceptible difference, this is a minefield. It’s difficult to know who to trust on the Internet, because opinion is not always borne out of fact, and it’s not always first hand, based on experience. There’s a hell of a lot of rhetoric on the web, which clearly started off as a hopeful sales pitch and then at some point found itself being accepted as fact. There are some really knowledgable people on forums and message boards, but equally, there are some people who just want to be part of the conversation and will happily give ‘authoritative advice’ on components they’ve never owned, used, or in some cases even seen.

I personally would always go to the source and read what the manufacturer has to say in the first instance. I'd then Google the model of part coupled with some negative keywords like "poor", "rubbish", "don't like", etc. Use the inverted commas around your keyword (only try one at a time), and separately around your product name, in the same search. For example: "Fred Bloggs Stupendo Lead Pickup" "rip-off"...
This forces Google to find that precise content, rather than serving up a list of nearest matches in order of site ranking, which is what it does by default. If there's any bad publicity there, this kind of search should unearth it. If no one has any rational or significant complaints, you should be able to cross reference what the manufacturer says with a couple of reviews, and rely on that. But always remember, sound is hard to describe, and people may not mean what you think they mean. Even audio recordings are subjective, because there are tons of factors which will change when you're using the part, as opposed to someone else.

A big issue connected with this is that the acoustics of a room, the type of mic used to record, and other variables often beyond the guitarist’s control, can easily warp an instrument’s sound into something a million miles away from that perfect sweetness you get in your lounge or bedroom. As I’m sure you’ll know only too well, there are some venues with such atrocious acoustics that you might as well be strumming a tennis racket for all the difference it makes. Is the exact spec of the bridge and machine heads really gonna be of any importance in most live or recording situations, where you frequently have to completely abandon an entire list of amp and effect settings and start from scratch? A question worth asking before you spend a large amount of money on a small change.

But the biggest issue of all (and this one’s the most depressing), is that the vast majority of your audience will not be able to perceive any difference between one guitar and the next, let alone one pickup and the next. Even the most sensitive souls in the building will not have any idea which capacitor you eventually decided to use – if you even do yourself. So, if you’re customising for your own pleasure, that’s fine. But if you’re customising to better impress your next live audience, then customise your hairstyle – ‘cos that’s the only thing most of them will notice!

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