more low-end from a single coil?

I might try 250K or even 500 K pots. The 50Ks could be holding back the treble. The .1uf cap could remain but would roll off a lot of treble if you turned the knob fully clockwise.

 

I'm guessing it's the pickup? Usually the higher the value of pot, the more treble you get if it's wide open. Perhaps try a higher value pot if you're looking for more treble. The cap only affects the tone as the tone pot is used I believe.

 

50k is way too low for passive single coils, it drops the impedance way below what it should be. It similar, but not identical to, turning down the volume to about 5 on any regular guitar.

The .1 uF cap is a decent value, but the schematic looks strange. The tone control decreases at the same time as the volume, so that zero tone is also zero volume. As you sure that's supposed to be a stacked pot and not a concentric pot? Is this stock wiring, or has this been modified?

 

Pst.. You can use higher value pots and just roll the tone back for the same effect... The first portion of the pot's range will roll the resonant peak off in the same way a really low value pot would. You're just looking to flatten out the resonant peak for that 'flat' jazz sound. IMO, you dont actually want rolled off highs for a jazz sound, but rather, a fairly even response across the frequency range. No 'scoop' in the mids, or accentuation of the upper mids or treble, for that mellow jazz sound. There are many different ways to achieve this. Without the mid scoop, or high end accentuation, it makes us perceive the pickup as having a stronger 'bass' but it's actually the flat mids that gives that jazzy sound, IMO.

 

all passive single coil pickups are born with the most amount of treble they're capable of delivering. given the same dimensions, build and material parameters, the amount of treble on tap is typically a product of the coil wire turn count. the more turns around the bobbin, the greater the midrange is accentuated and the treble is decreased ... but more turns will, by its nature, also increase the transducer's output. capacitance eats treble tone, typically by shunting those frequencies to ground. a .1 cap is a big treble eater. so is the circuit itself a treble sucker - the more wire and metal that the signal hasta travel, the more it will influence tone, and why having a switch to route a pup direct to the jack might be an eye/ear opener, but lotsa dependencies and there are no hard 'n' fast rules. for the most part, not too great a variance in pot values typically does nothing, and as we know, rated pot values can be off by huge amounts - it's quite common for a "250k" pot to be 210k or 290k, or somewhere in between. so in summary, either the passive pickup is wound to reduce treble, or it's modded via capacitance to reduce treble, or both. using capacitance may or may not be yer cup of tea, as it can do other things to the overall tone, typically muddy it up a bunch. i'm not a fan of caps to regulate treble. usually the volume pot works best as a tone pot for me.

 

As Rob says, the pickup has whatever inherent signal it can provide coming out of the two wires. So there is no way to get MORE lows out of an existing single coil although with a differently designed single coil pickup you certainly could get more lows. All you can do is change the EQ balance by cutting highs, mids, or lows. There's a wide variety of ways to do that with wiring schemes in the guitar or with something like an EQ pedal in your signal chain. You can also change the signal coming out of the pickup a little bit by changing the un-amplified signal going into it-- i.e., the pickup height and the strings. You will hear more lows and less highs with a nickel plated, flatwound, heavy set of strings vs. lighter gauge steel-wrapped strings, for example. The only other way I know of is to move the position of the pickup-- it sounds deeper as you move away from the bridge, again because you are changing the character of the un-amplified input signal.

 

It's also worth noting. A lot of 'Jazz pickups' are not wound 'hot' they're typically lower output pickups with less winds/inductance, which, when unfiltered would result in more high end content. Bill Lawrence, I believe used to wind .5Henry-1Henry pickups for jazz. These pickups would typically have extended highs, but I believe because they are wound to such a low inductance, the resonant peak sits so high, that it's out of the 'reach' of a typical guitar speaker. This would give a very wide bandwidth, but no spikes in the high end, making the pickup sound much more 'mellow' than one might expect. I noticed something very similar with my TV Jones Filtertrons. The TV classic is a low 1.4Henry (compare to a vintage strat pickup ~2.6Henries)
The neck pickup actually sounds very mellow and jazzy to me, even with 1Meg Volume and a 'No load' 1 Meg tone. You'd expect this to be a very bright sound, on paper, but I guess because the resonant frequency is up somewhere around 6Khz-8Khz, that peak is out of the bandwidth of a typical guitar speaker, which tends to roll off highs sharply at around 5Khz.
If I fully engage the 2.7nF tone cap in that guitar, it moves the resonant peak down towards 2400hz, and the pickup may sometimes appear to have more 'bite' even though less highs are present, the peak in the upper mids gives the pickup a more aggressive character.

 

That's a fun theory, but the same would be true of a split PAF, and they sound thin and weak. I actually split a Filter'tron with one of my Cabronitas, it sounds very plinky.

If anything, I suspect the mellow jazz tone owes more to the 50's era combo tube amps that lacked negative feedback and used AlNiCo speakers. They make anything sound mellow.

 

FWIW a PAF would split to roughly 1.9-2Henries, which would very likely still have a resonant peak in the guitar speakers bandwidth, depending on cable capacitance. The resonant peak would likely be around ~5khz, which would explain the 'thin' description. Depending which filtertron you split, the same could apply, especially if it's a hotter wind. The 1.4Henry Classics, are right on the edge or a guitar speaker's bandwidth. With a 300pF cable, the resonant peak is at ~7kHz, while with a 500-700pF cable the peak is roughly around 5000-5500khz. We dont see many pickups with inductances so low that it pushes the resonant frequency above a guitar speaker's working bandwidth, so it's not really something that comes up too often, and you'd need to split a humbucker measuring ~2.8H to achieve that inductance split, which again, probably wont be too common, outside of Bill Lawrence's designs.

 

Normally I would suggest a 250k volume, 250k tone and a .047uf cap for single coil. That pickup is most likely a very low output pup and probably wouldn't benefit much from that change. May need to change out the whole lot for a P90 or Lipstick Tube.
You could put a couple pots and cap and temporarily connect them to that pup just to try out first. It might surprise us.

 

That's a good point, but I've taken it further than that even: a Strat that allows all three pickups to be activated in parallel at once. With a combined parallel C of 350pF, L of .6H, and R of 2k, I see a resonance of 11kHz. I'd describe the tone as being closest to that of the neck and middle together, but even thinner.

As a side note, when I've done actual test comparing split versus parallel PAFs, you'd expect the resonance of the parallel mode to be a lot higher, but for whatever reason the end up being very close, possibly due to the increased parallel capacitance of the parallel wiring.

 

If thinner wire is used so more of an eddy-current free, very low capacitance coil of a certain shape is up closer to the strings, and the magnetic field is optimized for said coil, a very low inductance pickup with low value pots can sound very warm and full. I don’t imagine people generally use all three Strat pickups at once. While the fundamentals are slightly reinforced, there is less midrange and more harmonic cancellations. I guess that could be thought of as sounding thin. Flipping the phase of one, maybe with another in series might be cool.

 

Thinner wire won't mean less eddy currents, it will mean higher series resistance, which reduces the Q factor, which incidentally is also what eddy currents would cause to happen.

The magnetic field is never optimized for the coil, it's optmized for the strings, so that the moving strings will then induce flux change in the coil. The only optimization that is possible in this respect is to get the coil really close to the strings so that the largest degree of flux change can be imparted through that coil. A micro coil would be good for that purpose, since the size of the coil itself is practically the same size as the string displacement itself (a few millimeters) where as a Strat coil is much larger than the displacement, placing much of the coil far away from the moving string, where it's unable to see as much flux change, and therefore be productive.



The field geometry between the strings and the coil, and the cancellations you mention, has more bearing on the "voicing" of the pickup, which is harder to describe. When it comes to whether a pickup is bright or thin, or loud and fat, depends on how much inductance they manage to create. The inductance doesn't even have be in the pickup, you could wire the pickup in series with an inductor and get more inductance that way, too.

There's no mystery there, a low value pot will lower the Q and make any pickup sound more "warm and full" than it would otherwise, that's why Strats and Teles use 250k to the 500k usually paired with higher inductance humbuckers.

The premise of this thread is actually a little off base, in that there is no reason a single coil must sound thin and a humbucker must sound fat. Either one can easily be made to do the other, depending on the wind count and final inductance. I'm even willing to bet that this single coil, which as a metal cover, is never especially glassy sounding:

 

Or, you could put fatter strings on, and tune down...

 

Antigua, you are supposing some things based on limited research you've done measuring electrical properties. Also, your metering device may not be appropriate for measuring pickup inductance values. Bill Lawrence told me there is a particular equation involved in getting the correct value. I don't know the truth on that, but I'm not willing to say he was mistaken considering the innovation and precision of his products, and his overall knowledge and sense of discrepancy, and simply by virtue of the type of person he was. You will limit yourself by flippantly discrediting things you don't fully understand. There is also a somewhat condescending heir in your responses, as if you are trying to appear that you are never wrong, when you haven't done the research to be able to make certain statements about some things. Lighten up, will ya? Not everyone is challenging your "technical prowess" by correcting you. Maybe we are just trying to help you in your quest? If any of this rings true, you would do well to realize it sooner than later.

I did not mean to imply thinner wire coils have less eddy-currents shorts, but that simply being free of them is part of the whole equation. I thought it was clear it was just one part of a whole statement.

A pickup does benefit from having the field optimized for the coil/s. The width, strength and throw are all part of the sound. Core materials and structure affect those factors, as do eddy-currents. It takes serious know how to...know how to configure it all precisely. You can see a bar under the thin Nd magnet in the Microcoil in your picture. That affects the field shape. The affect would not be same on a different coil size/shape.

Getting more of the coil up closer to the string has more to do with increasing fundamental harmonic strength than voicing, but coil shape may affect voicing as well. I don't know the specifics of that. If you do, please enlighten.

How glassy a pickups may sound would depend on the type and thickness of that metal cover, and the resonance tuning. I think of "glassy" in the 4~6kHz region.

Oh, and clearly the wooden bridge on the guitar damps the high end.

 

The idea is to speak to the limits your knowledge, and not beyond it. Citing, or invoking the name 'Bill Lawrence' is not a substitute for genuine understanding. He might have even been wrong once or twice, the onus is on you to know if and when he made a mistake.

Your statement is confusing. Typical Strat pickups have very little eddy current losses, being entirely made of fiber flatwork and AlNiCo, aside from the coil itself. AlNiCo has a lower conductivity than the steel pole pieces and parts found in most other types of pickups. I wouldn't single out micro coils for being low in eddy losses.

It sounds like you're just making generalized statements without a deeper understanding of what it is you're saying, maybe you're deferring to something Bill Lawrence might have written at some point. You talk about "the sound" and the "field shape" in an abstract manner. Do you "know how to configure it all precisely"? If you say that you can't, then I'd contend that means you don't fully understand it, either.

I don't see any evidence that either the magnetic field width, nor the coil width of proximity to the string has any bearing on the fundamental / harmonic ratio, so explaining why it happens would be getting ahead of ourselves.

I actually do have a light grasp of what goes on with respect to harmonics and magnetic strength and proximity, but it's relatively complicated, so when anyone else claims to have an understanding, I'm all too happy to see how they attempt to explain it.

"glassy" is an ambiguous term, but suffice it to say that there are multiple factors determining the overall amount of treble.

Good observation.

 

My statement isn't confusing. You are just confused by it for whatever reason. Surely, lots of newer pickups with thin wire may have no eddy-shorts, but Bill was doing it back in the 70's at Gibson, and he claimed the Microcoils also have the densest possible coil, care of the pre digital era high speed auto-tensioning machines he designed. The friction created during winding even patches the insulation crazing, so post heat treatment is not required, and the insulation does not change thickness at the edges.

I already explained that I chose to believe what he had said somewhat on faith, but also on some evidence. There's no need to repeatedly point that out, as if it's a new idea. Sheesh...lighten up, guy. You can choose to believe his theories or not. In order to disprove his them, I would need to study physics, set up a lab, and do a lot testing. Frankly, the concepts make sense and the results jibe. I'm not prepared to spend my life researching something I'm not interested in pursuing. I drive a car because I've seen it work. I don't feel the need to know every detail to say that the steering wheel makes it turn.

Dude, I don't understand all the details of pickup configuration to the level Bill did. Very few people, if any, do. I believe I made that perfectly clear. The evidence of altering the individual note harmonic balance is in the very functioning of magnetism and how a coil amplifies a signal. If you understand what changes the harmonic balance of a pickup, why don't you explain it, rather than just imply that what I said is incorrect?! Just pointing out perceived flaws in an argument doesn't help anyone.

Academic debate tactics may show your ability to apply logic, but it won't help you understand pickups better if you refuse to consider things you aren't yet aware of. You can find ways to test theories like Bills, and/or find some academic writings about it, but saying something is not true because you aren't aware of it is no better than claiming something is true without citing documented research. I'm not trying to build pickups, but you apparently are. Believe what I'm saying or not - - makes no difference to me, but arguing about it won't get you anywhere, and you are the one who wants to know the truth to aid in your designs, no?

Try to relax about it all, though. It may help you find solutions to perplexing things. As it is now, I find it very unpleasant communicating with you. There's no warmth or joviality in your writing - - just plain old passive-aggressive one-upmanship. You harp on something even when I have already pointed out that I can't back up a particular claim - - that is essentially "tilting at windmills". You say you like to watch other people try to explain something that you calim to know about. Why? So you can jeer and point out why they are wrong and how you know so much more? Not fun or productive.

Some things are just simple deductive reasoning that come from a basic understanding of magnetic behavior. Arguing those things is like arguing that gravity will make a ball fall to the ground when I drop it. The answer is in the very function of gravity. I hope you find plenty of people to argue with about it all, if that's what you want. That's all I have to say on the matter. I suggest you take heed when I say this discussion has soured my opinion of you. You can ignore that, argue it, or point out my imperfections, but that won't make people want to engage with you.