Pickup making troubles

[ecmalmo]

Hi all. I got the idea a while back to start making my own pickups. Primarily humbuckers, feels more like a challenge, since single coils almost always sound great to my ears...

Once I managed to get the tension thing down, I managed to produce pickups with around 5000 to 5500 turns of plain enamel wire per bobbin with a DCR between 7500 and 8500 ohms. However, I wasn't a fan of the sound.. they seemed muted in the top end and a bit nasal and dull.

I got a LCR meter and it seems like the problem is too high inductance. This pickup has 5500 turns per bobbin and an Alnico 4 magnet:



5,6H at 100 Hz seems a bit on the high side for the turn count, but I could be wrong.. The capacitance is around 100 pf, and the DCR around 8500 ohms so nothing out of the ordinary. The cover is unplated nickel silver.

I measured a Seymour Duncan 59 Bridge for comparison. It measures 177 pF, so more capacitance, probably due to a longer lead wire, but lower inductance and DCR at 4.98H and 8250 Ohm respectively.



Is the answer just to lower the wind count and inductance to get a higher freq resonant peak, or are there other factors to work with? Less tension? Stronger magnet?
I wound a similar neck pickup with 5000 winds and ended up at 4,5H, probably a bit to high for the neck, I could try lowering the wind count to 4800 and 5200 for neck and bridge and see where that gets me.

[stratotarts]

Nov 12, 2021 8:44:27 GMT -5 ecmalmo said:

Is the answer just to lower the wind count

Yes. It's the most influential factor.

[gckelloch]

The thin PE insulation can split around the bobbin ends depending on what it's made of. Excess tension can cause increased eddy current losses via semi shorts. The solution used to be to heat coils to 125C within a few hours of winding, but that would melt some plastics. Polyester wire insulation stretches, which increases capacitance. What are you using for tension? Human hands are not reliable.

What is the capacitance of your guitar cable b4 the first preamp?

I have a 160pF cable that actually makes the 7.8k DCR GFS "Lil '59" Mini HB sound a bit dull in the neck of the all-mahogany Xavier "XV-585" guitar it's in. I'd either have to change one of the pots to a 1M or add some capacitance to solve that. I imagine the issue would be compounded with an AlNiCo IV magnet, which produces a warmer note timber and a slightly less strident attack than V. You might consider at least removing the cover. Sometimes that can make enough difference, but I would wind a bit lower as well.

[ecmalmo]

I use a small vice with felt pads for tension, and a small clamp, also with felt to guide the traverse. I've come up with the setting through simple trial and error... According to the coil estimator I get results that are around the "loose machine" range. If I loosen the tension I tend to get overly high DCR for the same wind count (like 9 K for 5500 turns) and it's a lot harder to fit the wire on the bobbin.

I have not measured the cable, but It's pretty short, maybe 6 feet. I use the same cable all the time, so It should affect all my guitars/pickups equally.

I'm starting to think the Schatten style winder and hand guiding won't give me the results I like anyway for humbuckers, but I will wind another set and see If I can get some better results before I give up...

[antigua]

I agree that the answer it just fewer turns. Maybe try something less than 5000 turns. I think it's best to keep the tension as high as possible, the capacitance is trivial, and the majority youre seeing is certainly from the hookup wire. The difference the magnet makes in a PAF is no more or less influential than how close the pickup is set to the strings.

[gckelloch]

Before you give up, you might try this 42AWG wire along with reducing the wind count:
www.remingtonindustries.com/magnet-wire/magnet-wire-42-awg-enameled-copper-5-spool-sizes-2-colors/

Elektrisola makes some of the best coil wire in the world. The Polyester-polyimide insulation combo sounds like an ideal solution to minimize stretching, and there shouldn't be any splitting around the edges. It's also less than half the price for the same wire length as the Stew Mac Poly wire (which doesn't list insulation specs). Either way, it would be a relatively inexpensive experiment. As far as keeping the tension consistent, is there a way to not use your hands at all to feed the wire? Seems like the wire would generally fall into the lowest point on the coil if the tension is consistently optimal.

[ecmalmo]

I wound a new set using the same magnets and other parts. Tried 5300 screw side and 5200 slug side on the bridge and ended up at 5.1H. To me this sounds just about right, nice highs, but still some push. "Tele on steroids" territory.

For the neck I tried 4800 screw and 4900 slug, and ended up at 4.3H. It's better but still a bit muted in the highs. I could probably go a bit lower to like 4700 and 4800.

I compared them to some Seymour Duncans and I like the bridge better than the APH-2. For the neck I still prefer the APH-1. But all that could be down to them being uncovered while mine are covered. The Slash bridge pickup uncovered definetly has a really piercing nasal resonance. A cover might do good in taming it. Made a little video for reference.

I used plain enamel to be "vintage correct" for these but I do have some spools of elektrisola poly 42 AWG in case I need it.

[gckelloch]

I agree that your bridge pickup sounds better than the APH-2. I think the difference in highs is mainly a combination of the covers and the AlNiCo grades. While II has about the same Gauss as IV, IV is ~2x (or more) permeable -- could be why the inductance readings are a bit higher than expected. So, while the strings aren't being pulled on significantly harder, the flux lines from the strings are pulled down more into the center of the pickup toward the magnet. What I hear is a more "meaty" sound from your pickups, as well as a bit less highs from the covers.

You could change one of the neck pickup pots to a 1M if you don't want to remove the cover or wind much lower. I'm not sure winding lower would really increase the highs anyway with Fe core pickups: as the resonant peak is shifted up and the Q is increased, the high end is further reduced by the Fe core.

You might also try the neck pickup in the bridge position just to see if you really prefer a higher inductance pickup there. I'd actually aim for more like 3~3.5H & 3.5~4H so you can get better 4kHz+ articulation. You can always turn the tone knob down a bit if there's too much high-end, and the AlNiCo IV seems to offer plenty of warmth and punch. Might be worth trying a low inductance set anyway just to see if you really don't want it.

[ecmalmo]

Thanks a lot for the advice! It’s inspired me to try some more, will wind a lower inductance set and see how I like it. I have a lot of parts around..

Do you believe the wire insulation has any effect? Anecdotally I’ve found that when I wind with poly they come out a bit brighter and ”wetter” if thats an adjective that makes sense (more or different harmonics I guess). I get similar inductance numbers regardless of wire, but I find that plain enamel ”attracts” more wax in the coil when potting. Cutting and stripping off a PE coil nets a lot of wax flakes, but the poly seems to be dry beneath the surface layer.

[gckelloch]

Nov 15, 2021 13:49:00 GMT -5 ecmalmo said:

Thanks a lot for the advice! It’s inspired me to try some more, will wind a lower inductance set and see how I like it. I have a lot of parts around..

Do you believe the wire insulation has any effect? Anecdotally I’ve found that when I wind with poly they come out a bit brighter and ”wetter” if thats an adjective that makes sense (more or different harmonics I guess). I get similar inductance numbers regardless of wire, but I find that plain enamel ”attracts” more wax in the coil when potting. Cutting and stripping off a PE coil nets a lot of wax flakes, but the poly seems to be dry beneath the surface layer.

From what little I know, the old PE (lacquer) insulation has thickness inconsistencies, as well as potentially splitting around the bobbin edges. Those two factors are likely responsible for the tonal difference. If the coil is thicker with the same winds of PE, that would also affect the result. Relative coil capacitance could be an issue, but it sounds like you are getting very low capacitance with PE anyway. Maybe try winding a neck pickup with Poly and the bridge with the PE and/or use AlNiCo II or V for the neck?

It does sound like the AlNiCo IV magnets in your demo, and in two others I've heard on YT, produce stronger lower harmonics than either II or V. That might be from the flux lines reaching down further into the center of the pickup, and creating the same effect as raising the coil, but without increasing string pull? The advantage is that you could wind lower without the tonal balance being too trebly under the same R & C load. So, a resonance peak up in the 4~4.5kHz range would give the guitar a more chimey sound, but there should still be ample warmth. Maybe, keep the 5.1H bridge pickup for reference, and wind a lower inductance one to compare if you find the 4.3H neck pickup not too bright in the bridge? Surely the parts aren't very expensive if you look elsewhere than places like Stew Mac?

I also don't think it's worth comparing pickups of less than 10% inductance difference. Even a 10% difference is hardly worth the trouble. The tonal difference is just too slight compared to other factors affecting the tone. FI, one notch on a tone knob will easily make as much tonal difference as 10% higher inductance. The results will also change depending on the amp, or even the first preamp tube in the same amp.

BTW, nice choice on the Ceriatone Plexi. Precisely, what are you using for preamp tubes in there? If you haven't sourced some prized NOS tubes you are particularly fond of, have you considered the new 7025EH? They sound very much like original Mullards. Best new 12ax7, IMHO, as well as amp builders like Dave Freidman and others: not super high gain, but very low noise with no measurable microphonics and a rich "round" harmonic sound.

[antigua]

Nov 14, 2021 19:40:36 GMT -5 ecmalmo said:

I wound a new set using the same magnets and other parts. Tried 5300 screw side and 5200 slug side on the bridge and ended up at 5.1H. To me this sounds just about right, nice highs, but still some push. "Tele on steroids" territory.

For the neck I tried 4800 screw and 4900 slug, and ended up at 4.3H. It's better but still a bit muted in the highs. I could probably go a bit lower to like 4700 and 4800.

I compared them to some Seymour Duncans and I like the bridge better than the APH-2. For the neck I still prefer the APH-1. But all that could be down to them being uncovered while mine are covered. The Slash bridge pickup uncovered definetly has a really piercing nasal resonance. A cover might do good in taming it. Made a little video for reference.

I used plain enamel to be "vintage correct" for these but I do have some spools of elektrisola poly 42 AWG in case I need it.

If you're getting to the point where you're tweaking the inductance by 250mH +/-, it might make sense to start keeping track of the capacitance of the guitar cable, and see how it sound with a short and a long cable to see if your tastes also vary by guitar cable. Adding a low value cap in parallel, like 470pF will move the resonant peak downwards by about an equivalent of a 100mH (I could work out the exact number if you're interested). You might also consider the influence of the guitar strings, if they're older and oxidized, they will mute high harmonics in a very similar way that a lower resonant peak mutes higher harmonics. I used Elixir strings, and I'd say they're always about 75% brightness of ordinary new strings, from the day they're new until the day they break. 

[gckelloch]

Nov 15, 2021 17:41:26 GMT -5 antigua said:

Nov 14, 2021 19:40:36 GMT -5 ecmalmo said:

I wound a new set using the same magnets and other parts. Tried 5300 screw side and 5200 slug side on the bridge and ended up at 5.1H. To me this sounds just about right, nice highs, but still some push. "Tele on steroids" territory.

For the neck I tried 4800 screw and 4900 slug, and ended up at 4.3H. It's better but still a bit muted in the highs. I could probably go a bit lower to like 4700 and 4800.

I compared them to some Seymour Duncans and I like the bridge better than the APH-2. For the neck I still prefer the APH-1. But all that could be down to them being uncovered while mine are covered. The Slash bridge pickup uncovered definetly has a really piercing nasal resonance. A cover might do good in taming it. Made a little video for reference.

I used plain enamel to be "vintage correct" for these but I do have some spools of elektrisola poly 42 AWG in case I need it.

If you're getting to the point where you're tweaking the inductance by 250mH +/-, it might make sense to start keeping track of the capacitance of the guitar cable, and see how it sound with a short and a long cable to see if your tastes also vary by guitar cable. Adding a low value cap in parallel, like 470pF will move the resonant peak downwards by about an equivalent of a 100mH (I could work out the exact number if you're interested). You might also consider the influence of the guitar strings, if they're older and oxidized, they will mute high harmonics in a very similar way that a lower resonant peak mutes higher harmonics. I used Elixir strings, and I'd say they're always about 75% brightness of ordinary new strings, from the day they're new until the day they break. 

250mH is only 5% of 5H. Yeah, that's kinda' ridiculous to bother with. You'd notice it less than angling your pick very slightly one way or another. I wouldn't bother with less than 10%, and I'd start with a value you definitely find to be too low, and then zero in on what sounds best to you between it and the 5.1H for the bridge and the 4.3H neck, which are both as high values as I assume you'd consider for either position. BTW, adding 470pF to a 5H pickup will shift the resonance peak more than a magnitude more than by adding 100mH. You sure you meant to that value antigua?

Good point about string brightness consistency. Coated strings do resist corrosion, and they start off a bit darker as well. I've been trying various Sfarzo brand FeNi formulas since 2006, and they also stay more tonally consistant throughout the lifespan The micro-coated Alloy5109 (FeNiCo) are very nice but don't have quite the clarity of uncoated strings. I'm just trying the cryo-treated "Touchstones" now -- definitely brighter than the Alloy5109 or my most recent uncoated favorite "V-Strings". Various alloys have different stiffness. Along with the wrap to core ratio, alloy stiffness affects the harmonic "purity" of the vibrations. FI, stiffer alloys sound brighter, but also "colder" i.e. sharper higher harmonics and unrelated artifacts. The slowly-induced cryo-treatment is supposed to strengthen the alloy and smooth the surface via increased molecular alignment. They do feel smoother than the V-Strings, but I won't know how much tonal change there is for a while yet. I imagine they will last longer than most strings. They are unfortunately hard to find retail, though. You may have to order direct from Sfarzo to get the gauge you want. I was able to get a few 9-42 sets cheap online.

[antigua]

Nov 15, 2021 18:52:25 GMT -5 gckelloch said:

Nov 15, 2021 17:41:26 GMT -5 antigua said:

250mH is only 5% of 5H. Yeah, that's kinda' ridiculous to bother with. You'd notice it less than angling your pick very slightly one way or another. I wouldn't bother with less than 10%, and I'd start with a value you definitely find to be too low, and then zero in on what sounds best to you between it and the 5.1H for the bridge and the 4.3H neck, which are both as high values as I assume you'd consider for either position. BTW, adding 470pF to a 5H pickup will shift the resonance peak more than a magnitude more than by adding 100mH. You sure you meant to that value antigua?

I don't think 250mH is a trivial difference, because human hearing is sensitive to frequency. If you have a signal that is harmonically dense, then you can perceive the harmonics being attenuated. It's only in the case that the harmonics are spaced out that you can drop the resonant frequency and not notice, so 250mH can be significant depending on what you're playing, single notes of full chords. 

Regarding the mH and pF, like I said, I didn't do the math. The point is that it would be easier to use a cap to move the resonant peak than to wind a whole new pickup. 

[gckelloch]

Nov 15, 2021 20:30:26 GMT -5 antigua said:

Nov 15, 2021 18:52:25 GMT -5 gckelloch said:

250mH is only 5% of 5H. Yeah, that's kinda' ridiculous to bother with. You'd notice it less than angling your pick very slightly one way or another. I wouldn't bother with less than 10%, and I'd start with a value you definitely find to be too low, and then zero in on what sounds best to you between it and the 5.1H for the bridge and the 4.3H neck, which are both as high values as I assume you'd consider for either position. BTW, adding 470pF to a 5H pickup will shift the resonance peak more than a magnitude more than by adding 100mH. You sure you meant to that value antigua?

I don't think 250mH is a trivial difference, because human hearing is sensitive to frequency. If you have a signal that is harmonically dense, then you can perceive the harmonics being attenuated. It's only in the case that the harmonics are spaced out that you can drop the resonant frequency and not notice, so 250mH can be significant depending on what you're playing, single notes of full chords. 

Regarding the mH and pF, like I said, I didn't do the math. The point is that it would be easier to use a cap to move the resonant peak than to wind a whole new pickup. 

Sure, you could probably tell if you did a quick A/B between a 5H and 5.25H pickup wound with the same wire and tension, but the difference would likely be less than one notch down on a tone knob. Yes, altering the C & R load of a lower H pickup makes more sense to me too. Adjusting coil and/or pole screw heights by less than a screw turn could then make up for the output difference...which brings up another point. The dynamic envelope depends on the coil and pole screw heights with a given Guass level. Some players can't live without that edgy attack and relatively cold timber of a strong Gauss/non-permeable C8 magnet, and some prefer the soft warmth and harmonic "purity" of a weak Guass/high-permeable AlNiCo III.

[ecmalmo]

Nov 15, 2021 16:40:01 GMT -5 gckelloch said:

It does sound like the AlNiCo IV magnets in your demo, and in two others I've heard on YT, produce stronger lower harmonics than either II or V. That might be from the flux lines reaching down further into the center of the pickup, and creating the same effect as raising the coil, but without increasing string pull? The advantage is that you could wind lower without the tonal balance being too trebly under the same R & C load. So, a resonance peak up in the 4~4.5kHz range would give the guitar a more chimey sound, but there should still be ample warmth. Maybe, keep the 5.1H bridge pickup for reference, and wind a lower inductance one to compare if you find the 4.3H neck pickup not too bright in the bridge? Surely the parts aren't very expensive if you look elsewhere than places like Stew Mac?

I like the 5.1 bridge, but I also like to experiment so I will probably wind a new set for comparison. I have a lot of parts from AliExpress and Philadelphia Luthier supplies around.

[ecmalmo]

Nov 15, 2021 16:40:01 GMT -5 gckelloch said:

BTW, nice choice on the Ceriatone Plexi. Precisely, what are you using for preamp tubes in there? If you haven't sourced some prized NOS tubes you are particularly fond of, have you considered the new 7025EH? They sound very much like original Mullards. Best new 12ax7, IMHO, as well as amp builders like Dave Freidman and others: not super high gain, but very low noise with no measurable microphonics and a rich "round" harmonic sound.

It sure is a nice amp and it has some mods I did to make it more flexible, switchable bright caps, switchable shared/split cathode on V1 and switchable mid cap.
I'm not so into different tubes, I just buy a bunch of JJs and switch them when they break... 

[ecmalmo]

Nov 15, 2021 17:41:26 GMT -5 antigua said:

Good tip with the cap, If I understand correctly I can put in a low inductance pickup and use a clip on cap to simulate a higher inductance (sans the higher amplitude). I guess there is no way to simulate a lower inductance.

[ecmalmo]

Did another version for the neck position. Now the inductance is pretty bang on what I was aiming for. 4600 winds on the screw bobbin and 4800 on the slug. I increased the unbalance between coils to see if that opens it up more. 7.3K DCR.

[gckelloch]

Nov 16, 2021 11:05:22 GMT -5 ecmalmo said:

Did another version for the neck position. Now the inductance is pretty bang on what I was aiming for. 4600 winds on the screw bobbin and 4800 on the slug. I increased the unbalance between coils to see if that opens it up more. 7.3K DCR.

Hmmm...I should think the difference in coil size would hardly be significant to noticeably affect the tone or output between the coils compared to the overall inductance drop, but it certainly doesn't hurt anything. My understanding is the difference in mass/and alloy of the screws vs slugs creates an imbalance anyway. So reducing the coil of whichever core has more mass should minimize hum and balance mutual output. I assume the lugs have more mass and high permeability than the screws? Another way to get a brighter tone is to simply raise the screws up and lower the pickup accordingly, but it tends to sound more like a SC then.

Yet another way to open up the high end is a "brighter" tube in V1 of the amp (like the 7025EH ). Tubes do make a difference for things like the "S-curve", compression level, audible harmonic generation at a given V level, "swirl", noise, and microphonics. All that matters at least as much as a 10% pickup inductance difference. The 7025EH is actually similar to the JJ ecc83MG (Medium Gain), but with richer harmonic generation from what I heard in a few demos. JJ tubes all tend to have a tight vacuum, but for a few more recent offerings. That gives a tube "harder" sound. It could just be that lower internal heat allows the tube to remain cleaner up to the point of plate saturation, making it clip harder. I think the idea is that looser vacuum tubes generally sound better in guitar amps, but there is a limit to how loose the vacuum should be to retain a level of. My impression from many comparisons I've heard over the years is that it's has a forward upper-mid character without the higher harmonics of other tubes, but that could have to do with how the relatively high gain level "triggers" the dynamic high-end roll-off in a given circuit...or something like that. The ecc83S is supposedly one of the highest gain 12ax7's made. Either way, there are definitely brighter sounding 12ax7's. Even the ecc83MG is a bit brighter, but I think the 7025EH is just a better-sounding Marshall-style amp tube. It's also a Mil spec tube. So it should be very reliable, and it's inexpensive. Mil spec tubes may not normally have a sweet break-up character, but this one sounds very nice. Most distortion from a Plexi comes from the PI tube anyway, so it might be great there as well. You might at least try one for V1. Incidentally, The new PRS HDRX amps ship with 3 x JJ ecc803S tubes. Those are "long plate" tubes with just a bit less gain than the ecc83MG. The demos of that amp sound great to me, but it's a less aggressive sound than you might want. They can be nice in the PI slot if you want more of a power tube-like break up without the mid "grind" of the ecc83S. The long plate Sovtek 12ax7LPS is another good PI slot tube with more high harmonic generation than the ecc803S. Those two tubes are not recommended for the V2 cathode follower stage though because of a low Voltage rating in a relevant section of the tube. I assume PRS knows about that, but they may start getting V2 slot ecc803s failures if they did not somehow compensate. So, I'll leave off now about tubes at that.

If I didn't post this b4 antigua replied, adding a cap won't increase the overall pickup output, but it can increase the the level of the resonance peak depending on a few factors. The main thing is it will shift the peak freq down. That can make the sound harsher if it's in the most sensitive 3-3.5kHz human hearing range. I would not recommend trying that value, but you could try more like 1nF on the tone knob to get a ~2kHz peak with your pickups when the knob is down. I've done that on a few guitars. It's a versatile option I find more useful than a typical high-value cap like 10, 22 or 47nF.

Love to hear your latest neck pickup when you get a chance.

[ecmalmo]

Well you make a good sell, I might become a convert from the church of JJ that I've been in since oh 2001... 

I made a quick clip: 

There is certainly a bit more highs, distorted I could go either way, but clean the new one is better, less muffled. I like the balance between the bridge and neck more now. I kept the old neck pickup in case I want to try it in the bridge in the future.

[gckelloch]

I'm not saying EHx is better than JJ. JJ has some nice tubes. I think the ecc83MG is a marked improvement over the ecc83S. From what I've heard, I particularly like their KT88, and the recent EL34II has more upper-harmonics than the standard EL34, and a smoother sound -- might have a looser vacuum among other minor differences. Their standard EL34 and 5881 are also pretty nice, if not somewhat "vanilla". The EL34L is good if you want a bigger sound with more midrange from a small combo, and a tighter response than the KT88 that helps with an open-back cab. I'm just saying various tubes from each of the three factories are better than others. FI, I think the recent Tung Sol (Reflektor factory) 7581A is the best new 6L6 type, but I haven't heard any demos of the new TAD (Psvane factory) 6L6GCM-STR. The ShuGuang factory burned down a while back. Dave Friedman said he thinks Psvane is planning more guitar amp tube offerings.

I do hear a slight difference in your neck pickups. It could be from very slight pickup height differences, that one coil is slightly lower output than the other, the inductance difference (4.1H?), or all of the above. I still think it's worth trying a lower Inductance pickup, or you could experiment with a Wilde "Q-Filter" on the tone knob and be able to dial your pickups down as low as ~1H, or just shift the resonance freq way up with a mid dip and no bass response loss (or some loss) depending on how it's wired.

[ecmalmo]

I don’t have any real preference to JJs, they are just the cheapest and easiest to get hold of here in Sweden, but next time I’ll check out some of the alternatives you mention and see (or hear). Thanks for the tips!

I think I’m done with this guitar for now. It has the classic Les Paul tone I was after. One last thing though, I’m going to do some measurements on the original (very bad sounding) PRS pickups and post here

[gckelloch]

Nov 17, 2021 1:51:20 GMT -5 ecmalmo said:

I don’t have any real preference to JJs, they are just the cheapest and easiest to get hold of here in Sweden, but next time I’ll check out some of the alternatives you mention and see (or hear). Thanks for the tips!

I think I’m done with this guitar for now. It has the classic Les Paul tone I was after. One last thing though, I’m going to do some measurements on the original (very bad sounding) PRS pickups and post here

I thought you were in the States. I guess you can order tubes from TAD? Psvane has indeed just released a robust EL34-STR "Redbase" through TAD that's modeled after the original Telefunken with large cooling fins. A bit pricey, but the one reviewer says they sound as described. EL34's have a history of failing from raw bias feed "runaway" when driven hard in original Plexis. Ceriatone may specify a higher value resistor on the tube socket to protect from that (which also dulls the response), or the current is just lower, but big cooling fins are a good idea anyway. You can actually rewire the power section to self limit the raw bias feed without the response loss of a higher value resistor, but you'd have to look into how it's done, and you can't then use beam tetrodes in the amp. Hiwatt and Traynor amps were wired that way.

TAD also has the EHx 7025EH at a good price here: www.tubeampdoctor.com/en/eh-7025-electro-harmonix/russia

Glad your pickup winding worked out for you.

[antigua]

Nov 16, 2021 11:05:22 GMT -5 ecmalmo said:

Did another version for the neck position. Now the inductance is pretty bang on what I was aiming for. 4600 winds on the screw bobbin and 4800 on the slug. I increased the unbalance between coils to see if that opens it up more. 7.3K DCR.

The cap in parallel moves the peak f down. A high Q factor inductor like the Bill Lawrence Q filter can move the peak back up, but it depends on the inductance of the inductor, and that's a lot harder to pick and choose than caps.  

I don't think coil imbalance makes a big difference in the tone, because I've used the Seymour Duncan "Triple Shot" and demo'd the sounds of the respective coils and the sound difference was very slight, more slight in the neck pickup than in the bridge, but when you slightly imbalance coils, you start with a small difference and make it even smaller. But there's one thing to also be aware of, the coil imbalance works difference depending on whether the pickup is series or parallel, if you wire it in series, the hotter pickup is louder, but in parallel, the hotter pickup is quieter, because you will have mismatched the impedances of the two coils, and the different wiring configurations take the coil impedances into account. As a matter of fact the same issues occur with series and parallel speakers of mismatched impedance. 

[gckelloch]

Nov 17, 2021 15:48:52 GMT -5 antigua said:

Nov 16, 2021 11:05:22 GMT -5 ecmalmo said:

Did another version for the neck position. Now the inductance is pretty bang on what I was aiming for. 4600 winds on the screw bobbin and 4800 on the slug. I increased the unbalance between coils to see if that opens it up more. 7.3K DCR.

The cap in parallel moves the peak f down. A high Q factor inductor like the Bill Lawrence Q filter can move the peak back up, but it depends on the inductance of the inductor, and that's a lot harder to pick and choose than caps.  

I don't think coil imbalance makes a big difference in the tone, because I've used the Seymour Duncan "Triple Shot" and demo'd the sounds of the respective coils and the sound difference was very slight, more slight in the neck pickup than in the bridge, but when you slightly imbalance coils, you start with a small difference and make it even smaller. But there's one thing to also be aware of, the coil imbalance works difference depending on whether the pickup is series or parallel, if you wire it in series, the hotter pickup is louder, but in parallel, the hotter pickup is quieter, because you will have mismatched the impedances of the two coils, and the different wiring configurations take the coil impedances into account. As a matter of fact the same issues occur with series and parallel speakers of mismatched impedance. 

Ah, so the relative output of two inductance balanced coils shouldn't change in series or parallel if you simply raise the pole screws in one coil to get more definition. You would have to start with inductance balanced coils though, and I suppose the relative mass and permeability of the PAF style coils makes that harder to achieve?

[antigua]

Nov 17, 2021 17:31:51 GMT -5 gckelloch said:

Nov 17, 2021 15:48:52 GMT -5 antigua said:

Ah, so the relative output of two inductance balanced coils shouldn't change in series or parallel if you simply raise the pole screws in one coil to get more definition. You would have to start with inductance balanced coils though, and I suppose the relative mass and permeability of the PAF style coils makes that harder to achieve?

The screw coil has less inductance than the slug coil in most cases, because the screws are less permeable overall than the slugs, but the difference is small. If the imbalance is small, like 5% then it doesn't make much difference in sound or humbucking, but if the difference was like 50%, then switching between series and parallel would be like switching coils as well as overall inductance.

In fact the reason parallel sounds weak in the first place is because of the overall impedance drop that occurs. The magnemotive force is what determines the current, and it's always the same. I think messing with the pole pieces is a better way to induce and imbalance, but even still the reason PAF's have one row of screws is so that they would look like P-90's, the designers never cared wither the player would imbalance the coils, or adjust the filter screws at all.