PaF Pickups with tim Mills
Guitarist talks to Tim Mills from Bare Knuckle Pickups about the magic of the PAF – the ’57 Les Paul Custom’s powerhouse – and how he is on a mission to capture the sound of an era
It’s a misty and damp day at Bare Knuckle Pickups HQ in Cornwall and we sit cradling mugs of tea while talking about that most cherished artefact: the PAF pickup. Sound is a very subjective thing, but most players will agree that there is a certain undefinable magic connected to Seth Lover’s mid-50s invention. Originally designed as a means to battle troublesome mains hum, with the PAF, Seth heralded in a golden era of tone and something that manufacturers everywhere have been battling to reproduce ever since. Few people know more about the goings-on inside a PAF than Bare Knuckle’s Tim Mills and our first question concerns the nuts and bolts of a PAF… Just what are the physical components that constitute that sought-after sound? “It’s down to the gauge of nickel silver in the baseplate, the material that you make the pole-keeper from, the material that you make your slugs and pole screws from, the dimensions of the pole screw heads, the type of Alnico magnet, 42 AWG plain enamel coil wire and the tension of the wire on the bobbins, the draw of the cover… Crucially, I find that the celluloid butyrate coil-formers are something that are often overlooked. On Seth’s very first prototypes there was no screw coil, just two slug coils. He initially just had a slug coil former tool made and I believe it was people from the sales team who came back to him and said that they needed more to talk about. So he had the idea of putting in a row of adjustable poles so that they could say that you could height-adjust the poles to balance the strings. That facilitated another coil-former tool to be made. The chances of the same tool-maker being used are pretty slim, although the job went to the same company, and when you compare a slug coil and a screw coil former in a PAF, the actual internal dimensions are slightly different, particularly around the island that you wind the wire around.
“Externally, there are slight differences, too, but it’s the area that you wind the wire around that is most important with regards to the tone. Obviously, if you reduce the area of the island on one bobbin compared with the other, those two coils are going to be asymmetrical, so even if you did have the same number of turns of wire on, it’s not going to be a perfect humbucker, because one coil will have a longer piece of wire than the other. We know that they didn’t have the same number of turns on either, so there’s a difference in the actual number of turns and the coil shape.” How variable was the spec of original PAFs? “Extremely variable. If you look at the original patent submission that Seth Lover put in, he was stipulating an elongated bar of permanent magnetic material and a pair of coils wound around formers. The machines that they were initially winding them on didn’t have an auto shut-off, so it was down to the operative to stop the machine when the coils looked full. Making an allowance for a pre-tensioner and the auto-traverse – which the Leesona machine that they were using by the late 50s would have had – you are going to get a fair variance in coils.
“Going from original coils I’ve inspected, you’ll get a variance in humbuckers with a DC reading of maybe mid to upper sevens – 7.5k to 7.9k, right up as high as 8.9k. In real terms, that can be a variance of around 1,000 turns of wire. With the magnets, you don’t actually see Alnico 5 coming in until late 1960. I’ve found Alnico 2, 3 and 4 magnets used, mostly Alnico 2s, but there were some Alnico 3s left over from P-90s and I suspect it was little more than whatever the suppliers had and gave them.” So did the PAF change over the time that it was issued? “Strictly speaking, no – if we’re talking about the original PAF. It is a ‘Patent Applied For’, which was submitted in 1955 and didn’t get granted until mid-’59, but other than the points I’ve already mentioned, up until late 1960 nothing really
changes in terms of design of the actual pickup. Up until that point it was common to find that the screw coil and slug coil had a totally different number of turns of wire, which is very much a part of that PAF tone as well as variance in the type of Alnico bar magnet. In 1961, a short Alnico 5 bar magnet was introduced and then a move to poly-coated coil wire. It’s my understanding that around this time they brought in auto shut-off on the winding machines and the wind becomes a lot more regular. It was pretty much bang on 5,000 turns per coil, which heralded the era of the ‘patent number’ humbuckers.” So the auto-cutoff machines would have destroyed the possibility of those odd, beautiful pickups happening? “Absolutely, yes. It’s interesting, because the later ‘patent number’ humbuckers kind of got their brightness and their dynamics just by being lower output, but because you’ve got almost uniform coils, that bloom doesn’t happen. It’s quite an aggressive tone, still very dynamic – you dig in and they come up with you – but that thing where the pickup feels like it’s talking on its own just doesn’t happen.” What are the tonal differences that occur from a disparity in turns between the slug and screw coils? “I call it ‘coil offsets’ and so if we’ve got a disparity between the two coils – say, the screw coil had 500 turns more than the slug coil – then we’re not getting total humcancelling. When something hum-cancels, you lose some of the very high frequencies and some of the very low frequencies, so we’re centring predominantly around the midrange, which is very much the character of a humbucker.
“So depending on the offset between those screw and slug coils, we’re drifting away from complete hum-cancelling and more highs and lows are coming back in. This is the ‘air’ and ‘bloom’ that you will hear referred to in the tone produced by early PAFs.” What’s the most unusual PAF pickup that you’ve ever encountered? “Probably the one in Jimmy Page’s Number One [Les Paul]. Jimmy sent Number One down here for us to have a look at – he was concerned that the neck pickup might fail. It was thought not to be original to the guitar, but was still an early PAF and it turned out to be fine. That one, when you played it, had the most hollow and woody Strat-like tone I’d ever come across in a neck pickup. When I measured it, it had a DC resistance of 8.97k, I seem to remember, which is extremely hot for a PAF. Normally, that would sound as thick as river mud!” What’s the best example you’ve seen? “There was a double black that came in and it was absolutely wonderful, it was a ’58 from memory. It had no cover on it at all and it had the vestiges of gold plating on the underside of the screws, so I assume it would have come out of a 335 rather than a Les Paul, and that one was wonderful. Even in our crude test guitar, it didn’t matter where you put your finger on the neck, the notes just erupted out from underneath. It literally talked! Very much the benchmark in my mind’s ear as to what I’m aiming for in a really dynamic pickup.” Do you think original PAFs really have magic that’s hard to imitate? “You can reproduce anything if you’re prepared to spend enough time. The problem then is to reproduce it consistently, and like all things that are worth doing well, it takes hard work to get the right results. A lot of PAFs sound quite something-andnothing and there are one or two that sound absolutely bloody horrible! It’s when you get the one or two really good ones that you think, ‘Crikey, that’s what the fuss is about.’ As a pickup builder, that’s what you aim to do – capture the magic.
“If you were to take one of those Holy Grail pickups and say, ‘Right, I’m going to recreate that…’, that’s fine, but would that then work for every player? Possibly not.
We’ve probably all got a different idea about sonic nirvana. So it’s about trying to find the best elements of all the good ones and that’s what I try to put into the voicings of my PAFs.
“The most important thing is to get the dynamic control in there. If you’ve got a pickup that is flat and has no real dynamic at all, then it’s like somebody talking in a monotone voice – it’s not going to flatter anyone’s playing and that will generally happen if you’ve overwound it or have too much tension in the coil. Any overwound pickup goes very, very flat and lifeless, so dynamics and trying to get that bloom in there are paramount.”
“We had a double black from ’58 – even in our crude test guitar, it didn’t matter where you put your finger on the neck… it literally talked!”