This kit contains all the parts required to make a “stacked and shielded” noise cancelling single coil.

Included in the kit are the following parts.
1 x ABS “bottom” bobbin

1 x ABS “Top” bobbin

1 x Steel “Gauss” Plate

6 x Mild steel “dummy” poles

6 x 5mm diameter Alnico poles (either staggered length – 3 x 10mm, 2 x 11mm, 1 x 9mm, or non-staggered lengths – 6 x 10mm)

2 x Height Adjustment bolts (6/32 UNC) and springs
2 x Bobbin Mounting Screws

4 x Eyelets

Please be aware, this kit is not supplied assembled, or magnetized.

Now – the fun part!

Normally, I don’t do big over the top write ups for pickup parts kits, purely because they’re normally pretty simple bits of technology, and most people will develop their own way of building the things up, with their own methods and ideas without my help.

Unfortunately, a “stacked and shielded” single coil, doesn’t really give you a lot of scope to “suck it and see” – they’re a disgustingly clever bit of kit, but they’re a little more complicated then a normal single coil, so I figured, I’d lay out “the theory” (and a little of the practical) just so everyone understands what’s going on.

It’s a Humbucker!

So, in very basic terms – a noise cancelling single coil, in any of its guises, is a humbucker! (be that a single coil sized rail humbucker like our TT73 or a Lace Sensor or a DiMarzio Fast Track, or a “stacked” single coil like this kit will build, or a DiMarzio Area or a Fender Noiseless, or even a bog standard single coil with a dummy coil hidden in the control cavity!) Two coils wound in opposite directions.

And a humbucker, “Bucks hum” – now, to understand how that happens, we first have to understand what “hum” is!

Its all do do with your power source – buried in your walls, the mains power cables are…. Humming. The cable going from the plug socket into the back of your amp, is humming. Simply put, 240 volt mains electricity has a frequency of 50hz, somewhere around a G.

And the antennae we insist on sticking in our guitars? Those weird and wonderful contraptions that make you sound amazing? Pickups… they’re really quite good at picking up external electrical interference – so, the electric guitar? Is picking up that 50hz hum from the electricity that is powering the amp. Unavoidable truth of guitars! (Some countries mains runs at 60hz (usually at 120v), but it’s the same idea (and its VERY normal for everyone to call it 60hz hum, regardless of where you live - i even wrote this article back to front out of habit!)) we then amplify the pickups signal, and we hear the hum.

Now, with a “single coil”, there’s nothing we can do to cancel this introduced signal (short of using a noise gate and shelving it hard at 50hz, but that’s not ideal) but if we have 2 coils? We can harness a concept known as phase cancellation!

If we have one coil wound in one direction (clockwise) and the other wound counter clockwise – the signals they produce, are mirror images of each other – and when you produce two signals in mirror image? Where the + of one matches the – of the other? It’ll cancel out to absolute silence!

And that’s humbuckers! Both coils are picking up the same interference from the mains, it phase cancels out, and we’ve “bucked the hum”

But a humbucker still produces guitar sounds?
The reason a humbucker isn’t completely silent, however (and I promise, I’m getting back to noiseless singles soon!) is because they 2 coils live side by side (at a center spacing of around 17mm) – one coil pickups up the string movement from one position, and the other from another – so, really, the only “constant” within the signals from both coil, will be the external interference.

So, the spacing between the coils is hugely important – to only “buck the hum” and nothing else, we have to ensure the coils are capturing the string movement from different places along the strings length, and, 17mm, roughly, is the goldilocks zone – any more or less then that, and we risk sitting within a strange position of the strings wave cycle on one of the coils, and that will cause more inadvertent phase cancellation.

And we can prove this “perfect storm of broken guitar” if we’re bored enough – take a bog standard single coil, and wind 2 coils onto it at the same time (I’ve done this!) – wire them in series – it’ll look to all the world like a functional pickup – it’ll give you a resistance and inductance reading, it’ll give you capacitance , but if you install it in a guitar? Silence!

This is known as comb filtering (more common in recording/mic placement, but it’s the same idea) – 17mm spacing is the perfect “mic placement” essentially.

A single coil can’t do that!
Nope! A stacked single coil, can only capture string movement from the same place (and I’d go as far as arguing that even the single coil sized humbuckers are spaced so closely, that your losing a huge amount of signal to comb filtering/phase cancellation that your hugely limited to what you can actually do with the idea!)

And that brings us to the nub of the problem.

Anyone with half a brain, could make a stacked single coil – its not rocket science, and if your clever about it, you can probably get it to make a noise too, but because the “bottom” coil is being excited by the same string movement as the top, its going to sound pretty weird (we see this idea on some of the very early “noiseless” singles)

And the answer to that problem – is the gauss plate. The metal “shield” that sits between top and bottom coil.

What that’s doing is, basically, redirecting the magnetic pull from the bottom of the magnets installed into the top coil, and sending it back up to the strings. The bottom coil, on a “stacked and shielded” isn’t actually being excited by the string movement what so ever! It is only capable of picking up external interference.

So, in terms of “single coil pickups that buck hum”? That’s the best you can really hope for! Top coil is making the guitar noise, the bottom coil is doing the hum cancelling.

Does the bottom coil need poles?
Strictly speaking, no! You can run the bottom coil (the hum cancelling coil) without poles of any kind – but, really, you probably want them in there, because, really, the bottom coil isn’t just cancelling the external hum, its also colouring the signal being produced by the top coil (in very simple terms, its causing signal degradation, and warming everything up), and to do that most effectively, you want to producing a signal on the dummy coil that’s got a similar inductance to the top “live” coil – and the simplest way to do that, is to have some iron within the coil – hence, steel poles.

Those steel poles aren’t carrying any magnetic charge thanks to the gauss plate shielding them, but they are effecting the signal.

The tricky bit…
The hard part of making a stacked single coil, sadly, is finding what specs actually work. The problem is, you can’t wind these things 4k @ 42 AWG Top, 4K @ 42 AWG bottom and tell your mates you’ve hade a PAF in a single coil.

Realistically, your getting about a maximum of 2K @ 42 AWG on each of the bobbins – and trust me, 4K of coils isn’t going to sound great. It’ll be noiseless, definitely, but also, probably going to feel like its suffering from a wasting disease.

So, it’s a little bit of a balancing act frankly. The general guide seems to be “top coil is wound HOT” (using either 43 or 44 AWG – I’ve maxed out a prototype coil here at 8K/3H using 44 AWG ) and then the bottom coil, you treat as the dummy – get enough wire on there to act as an antennae to the external interference, but not so much that you over colour the top coil – so 2K @ 42 AWG seems to be about right.

There will be, lurking in this idea, plenty of weird and wonderful tones, so please, feel free to experiment with the concept, but keep in mind that “top coil for signal, bottom coil for cancelling” thing, and you wont go far wrong.

Wiring
Thankfully, dead easy – doesn’t matter which coil is “the start” and which ones “the end” – I’ve been making the prototypes with the top coil as the first in the series, and the bottom last, but it doesn’t seem to matter all that much. Just remember, series wiring would be the norm (you could try parallel too, but series would definitely be more familiar)

Controls
Everyone gets this wrong – we apply a bit of broad logic, and think “these are noiseless! They’re humbuckers! Humbuckers go on 500ks!” – and its not strictly speaking true. They are humbuckers, but they wont be inducing at the same levels as a normal humbucker either, they’re, generally speaking, producing a very similar signal to a normal single coil (maybe, slightly hotter, and slightly darker as a result) – so, whilst I wouldn’t say it’s a hard and fast rule – you’ll normally be absolutely fine on 250k pots – it’s a single coil, treat it as a single coil, even though its actually a humbucker.