Getting the most out of factory pickups; MIM Fender Classic Series 50s Strat
In this article I'm going to share some of the ways I decide on wiring specs to help achieve a customers goal for their guitar's tone. As well as touch on some of the various steps I take when re-wiring a Fender Stratocaster. The specific guitar in question here was a lovely Classic Series 50s Stratocaster. A made in Mexico model which I'm always impressed by each time I get to see/play/work on. I've owned a couple of the slightly later variant of these, the Classic Player, which were great guitars but I've always liked both the Classic Series and Player models. Great vintage correct styling and build quality in my opinion is usually really nice on this era MIM, would happily own one again! 

The owner of this was considering a pickup swap to help get the guitar sounding a little more to his preferences and increase it's versatility, so popped along to my office for a chat and for a second opinion on that. Having worked on a number of these over the years, I was aware that the factory pickups on these can actually sound quite nice, they just need a nudge in the right direction. They are a fairly basic, plastic bobbin pickup set, low-ish output (5.7k DCR for each), and each have the same magnet direction (South Up) and wind direction (clockwise). So you don't get noise cancelling 2nd and 4th positions for example like you would if the middle pickup was RWRP, but you can certainly capture some great sounds from these basic pickups with a helping hand. That helping hand comes in the form of a re-wire, which is what he's opted for after our chat together and I'll go through the reasons why he agreed it's the direction to go in this time around.

The factory wiring, although reliable thanks to an Oak Switch and CTS pots, which are always built well for years of use. On this occasion (pots/cap specifically) won't be getting the best out of the pickups as the spec of CTS pot fitted to these models are the standard spec/range 20% tolerance items. In case you're not already aware, there are multiple 'series' of CTS pot, from more basic specs, to premium '450' series specs, and even within those ranges further spec choices which the commissioning company will have specified for their stocked range. Messy eh?! So with this guitar having 20% tolerance spec pots, this means that even if they're stamped 250k, they could read anywhere between 200k & 300k for example due to the manufacturer tolerances. This broad tolerance can yield unpredictable final results, something I have touched on before in more detailed articles. After plugging this one in, I had a feeling we had a broad mix of values in this one too, something I have experienced with my own Classic Players, and with other Classic Series I have worked on. Judging by how it sounded, perhaps on the 200k side of things by the warmer overall tone being heard. It sounded nice, but wasn't quite capturing the sound the owner was hoping for. So first of all, I think having some tighter tolerance pots will help us achieve more predictable results. Something the CTS 'SSSP' 450 series 250k pots with their 8% manufacturer tolerance will provide.

This was also equipped with a correct to vintage 0.1uF(Micro farad) tone cap spec, which is certainly period correct for a 50s style Strat. I will add it is nice to see Fender being true to original specs even on a non-USA produced model. They could have easily looked passed details like this, another reason I respect and like the Classic Series and Classic Player models. But in my humble opinion, when versatility is the goal, which it is here, this spec isn't always the ideal choice for every player. After chatting to Paul, I got the feeling he has similar tastes in Strat tones to myself, so I suggested swapping to a .022uF value. Something I use in my 'modern' spec kit and has been really popular with great customer feedback, as well as my SRV inspired 'Vintage modified' spec Strat kit for example.
A tone cap in a guitar's tone circuit to put it simply acts as a filter, allowing high frequencies to pass through to ground. What value is used will have varying results. Even with the tone pot on full, that cap is filtering some of those top end frequencies, but as you roll it down it is having further effect on the top end, this is where you'll notice more drastic results depending on value chosen. So what spec tone cap is fitted and which you choose during any upgrades/repairs absolutely has an effect on the overall tone and should be considered. 0.1uF is a spec you seldom see aside from vintage, and vintage correct instruments. Most commonly used by Fender in early basses and Strats for example, which is why you're seeing it here in this 50s reissue. These will sound 'darker' by comparison, both with the tone pot on full and certainly more so with the pot rolled down, which I think yields slightly more 'restrictive' tonal results for a player. Not a bad thing of course as this is all subjective, it just might not be for everyone. For example, if you have a 0.1uF and a .022uF hooked up to one guitar guitar, with the same pots, same pickups, same strings, same amp, same player, and are able to at the flick of a switch,change between each value, I am confident you will hear a difference between how the two handle the higher frequencies. Hit the bottom E, and you'll hear how those tamed top end frequencies make it sound from the 0.1uF to the .022uF. Same again as you hit the high E too, same notes, but how those frequencies are being handled will sound different. Which you choose will depend on how you like your overall tone and how you like to use your tone pots. 
At a sweaty pub gig, full band blasting, drinks flowing, it's doubtful you'll care too much, and let's be honest with ourselves, the crowd certainly won't! But if you're trying to get a guitar sounding how you like it to, and you know you've achieved that behind closed doors then when you're back at that gig, Strat blasting out, I suspect you'll have a big smile on your face happy how your guitar sounds and works. That's always a good thing, right?

So why do I suggest the .022uF for this? I find that this spec helps provide that 'glassy' (to use a common guitar term!) and clearer sounding bottom end, rather than the smoother, warmer overall response of the 0.1uF to my ear. Again, all personal tastes but I think this is one minor spec change that alongside some others will help achieve the tone the owner likes, and the versatility he's after too.

Furthering versatility: The guitar was wired as per the original 50s Strats, with the neck and middle pickups being wired to their own tone pot, but the bridge pickup having no tone pot resistance. So I think on this occasion, the combination of the particularly warm sounding neck and middle, with the super aggressive bridge pickup 'straight through' kind of tone, made for an extreme mix between the set. So in came the choice of my 'modern' wiring style, where the tone pot closest to the volume, works for both the neck and middle pickups, leaving the remaining tone pot exclusive to the bridge pickup. I like this layout as it is useful if you like a 'set and forget' tone pot setting for the bridge pickup, knowing that you can adjust the tone pot for that pickup alone and it won't have an affect on the other positions. In use this has always felt the most natural to me too, and thankfully with the 'Modern' Strat kit being the most popular I offer over the years, it seems customers do too which is nice! 

So first job was to slacken the strings, so I can lift out the current loaded pickguard. I then simply snip the three pickup hot wires, the three pickup ground wires and the spring claw ground wire as close to the pot casing and switch lugs as possible to leave me plenty of wire length to work with going forward. I then remove the two screws holding the jackplate on, and snip the hot and ground wires at the jack. As part of my full harness upgrade, I'm replacing the fairly basic spec jack (which is a switchcraft copy, non branded), with one of the quality Pure Tone multi-contact jack sockets I use as standard in my loom kits. I then removed the control knobs and switch tip which I can re-fit to the new CRL switch and CTS 450 series pots upon completing the re-wire as the originals are imperial specs too. With those removed, I can remove the two switch screws, and loosen the three pot mount nuts to lift off the original loom in one piece for safe keeping. I'm now left with a blank pickguard along with the pickups ready to get started on the new components.

I mount the 3x CTS SSSP 450 series 250k split shaft pots, along with my preferred switch spec, a CRL. These feature a spring loaded mechanism which have a firm actuation between each position, really confident switching I find so tend to prefer these as standard. 

With the switch and pots mounted up, before I start doing any soldering, I'm going to see how effective the piece of aluminium foil shielding is that was already applied to the pickguard. You'll often see some form of shielding tape on factory pickguards, but some work more effectively than others so for the sake of 30 seconds with the multi-meter, it's worth checking for continuity. This will tell me if there is solid ground continuity between the switch casing and each pot casing, which on this occasion there was indeed. Want to read a bit more about this process? Head to a recent article I put together on the very subject HERE.

Now I'm ready to begin soldering. I'm sure everyone has their own routine for this, for me I start with the volume to switch connection, then between the two switch common lugs, before moving on to the tone pot to switch connections and jack socket wires. All this is done using the very easy to handle, Gavitt USA 22awg cloth covered wire. This isn't for snake oil cork sniffing reasons by any means, or because it's simply what the vintage instruments use. It's because it is very easy to work with and is made consistently. I have gotten through thousands of feet of this over the years and it is of great quality. Reliability always wins for me! But it's ease of use helps too; pushing back the outer cloth covering to expose the central pre-tinned stranded copper core, make your connection and simply push the cloth covering back up to the joint neatly. Perfect!

Then onto fixing the chosen .022uF tone cap in place. 

With the bulk of the controls wired up, it was time to attach the pickups. I start with the ground wires here, then move onto the 'hot' wires to the switch.

This now sees completion of the 'loaded' pickguard so to speak. The final three connections are made during the final install, in situ. These three connections are the ground wire from the rear cavity spring claw, and the two wires onto the jack socket once they are fed through into the jack cavity.

Before I tighten everything back up, I take the chance to do a final continuity test, checking this time the bridge assembly as well as the jack on-top of a sanity check of the existing fitted components. After doing this, I plug the guitar into the amp and do a quick 'tap test'. This allows you to quickly check the functionality of the controls by lightly tapping each pickup's pole pieces to find out whether the switch selects the relevant pickup, the volume pot works as expected, whether the tone pots work. Doing these basic checks at this stage will save you having to remove multiple pickguard screws, remove strings etc if something is behaving strangely. Instead, you can easily just lift the parts out and investigate. Thankfully all was well here and I was ready to fix everything back down, get some strings back on it and hear the changes in action!

Lovely results on this one, factory pickups were sounding great to my ear and I think the subtle changes are allowing us to hear them at their best now. The controls/tone pot layout providing a little more adjust-ability for all three pickups, helping achieve the versatility goal set out. The tighter tolerance pots yielding more predictable results as expected, and the change of tone cap value over the factory installed spec, opening up the higher frequencies which in turn let the pickups breathe a little more. Had a great handover of the guitar with it's owner, playing it through my amp at the office with smiles being achieved which is what it's all about at the end of the day! I hope this article helps explain why we made the spec choices we did, to achieve the sound the owner wanted to try and capture from the guitar. Perhaps also showing that replacing pickups isn't always the first step to make, considering your wiring components is a valid choice to make. But if down the line you still want to do that then at least your guitar already has the best quality components in it ready to get the best out of them too. 

For pre-wired kits, separate components, wiring diagrams and further guides, please do feel free to browse the website where you'll find all of this discussed here. Or Have you made good use of some of the free resources here? Wired up your guitar or found useful info here along the way? Perhaps you might consider kindly supporting this free resource for guitarists via 'Buy me a coffee'! Thank you so much!


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