5-string P pickups with mismatched coils and hum cancelling

[Kro]

View attachment 4384933
Mine was silent, I wonder how Fender does it?

It's because close enough sometimes really is close enough. Heck, even the way you have your pickups angled there will effect the level of noise due to them not sensing noise on the same plane. Still, good enough.

My BBP Precision pickup is very quiet. And it isn't hard to test it against the noise from the J (also very quiet) to see that it provides a significant level of noise reduction (as has been specifically noted) even if it isn't perfect.

As has also been noted, for the shielding on the wires... that's nice, in the sense that it may reduce total additive noise... but it would do that for any pickup given that it's outside of any interference that the pickup itself would pick up (and may or may not cancel). To me it's an odd thing for SD to make such a big stink about, but I'm sure they have their reason. Hell, maybe it's even just an excuse to call out the fact that the 3/2 split pickup won't be as perfectly humbucking to the consumer.

Seems to me like if using shielded wiring is that much of an improvement they should just use it on all their builds. I dunno, happy to be corrected.

 

[Nedmundo]

IIRC, Fender winds the two halves of their five-string Precision pickup differently with different magnets. I know as much about pickup design as I do about disarming a nuclear weapon, but after this discussion, I see how they feel that might be necessary.

I would expect the pickup segments in a 3+2 to be wound differently, possibly for tone reasons but possibly to equalize the output. I don't know much about pickup design either, so I'm speculating here, but if the segments do in fact have similar output, then maybe they cancel hum as well as a symmetrical design.

 

[Kro]

This whole thing just makes me realize how much of a mishmash a 5-string PJ really is pickup-wise.

Kudos to those that are able to do it well, and I think Yamaha does, though I know they're not the only ones. Seems like something that would take either a lot of engineering or trial and error to really dial in.

 

[micguy]

There are manufacturers that do make "balanced" coils for a five-string P configuration, and leave out the pole pieces on one of the segments, since it is the coils, not the magnets, that do the humbucking.

That's not completely true - the coils need similar pole pieces to do their hum cancellation completely. Any pickup that has two parts that are reverse wound, reverse polarized, will, to some extent, cancel some of the hum. If it's a 2 and 3 arrangement, you end up with 1 "unit" of hum - 3 minus 2 is 1. A single coil in this math has 5 units of hum - hence a 3/2 unbalanced pickup has one fifth the hum of a single coil, (aka 15dB less hum). So, it's definitely progress, but not perfect.

The 5 string P pickups that cancel completely have a 6th pole piece (not magnetized like the others) - for complete cancellation, you need similar coils and pole pieces. That 6th pole piece (or pair of pole pieces), since it isn't a magnet, doesn't contribute to the signal from your strings, but if you don't have it, you won't completely cancel the hum. The 6th pole piece is also likely to be hidden from view, as it'd make OCD folks nuts if they could see it. When you see a pickup with two identical (in size) halves, and one has 3 sets of pole pieces, and the other has two that aren't centered, it's a good bet that there's a hidden pole piece (or pair of them) under the "2" side.

 

[Kro]

The 5 string P pickups that cancel completely have a 6th pole piece (not magnetized like the others) - for complete cancellation, you need similar coils and pole pieces. That 6th pole piece (or pair of pole pieces), since it isn't a magnet, doesn't contribute to the signal from your strings, but if you don't have it, you won't completely cancel the hum.

How does the pole piece have an effect if it isn't magnetized?

 

[micguy]

There are many asymmetric P5 pickup sets that are sufficiently hum-cancelling. And every J5 split-coil marketed as hum-canceling is asymmetric — as are quad-coil MM and split-coil soapbar 5s. Technically, yes, there is an issue, but in practice, they seem to work just fine.

They are asymmetric, but one of the secrets to a well made pair of 5 string J split coils is that one of the pickups is 3 plus 2 - the B, E and A are on one coil on the neck, for example. and the other pickup is a 2 plus 3 - the B and E are on one coil on the bridge pickup. What that all means is, when you have both pickups on, just like on a normal Jazz with single coils, the bass is completely hum cancelling. It's just unbalanced when a pickup is soloed, but never as unbalanced as a true single coil.

 

[thmsjordan]

Interesting that they cannot make a 3+2 fully hum bucking but not surprising. I can only say that the pickup on my new Fender Series II Precision 5 is dead quiet. I wonder if this mis-match is small enough to only be an issue on paper ?? Thoughts?

 

[MattZilla]

On P5's I've had little curiosity and always assumed that each coil would have something different about it to strive for balance… more/less winds, different gauge wire, different length and/or diameter poles… something.

but- there's tons of posters here who claim better than good enough silence on regular J's with one at slightly less than full volume and the other somewhere between almost off and about halfway up.

Everyone's "good enough" is different.

Like @Kro begins to imply, SD may just be ultra politely saying "it's not going to be as quiet as an active EMG, we did our best, so please just keep the pickup and don't try to return it or try to exchange a ton of emails and get angry about it not being totally the perfectest perfect pickup… piso mojado, don't slip!"

 

[thmsjordan]

View attachment 4384769

I just installed a set of these in my American Pro II Precision V. I also had a set of SD Apollo's installed in one of my American Pro V Jazz Basses. Got both back yesterday. Used both at last nights rehearsal. So far very impressed with both. The Precision really came alive and so did the Jazz. And both are dead quiet. No hum at all. I just had a set of Delano split coil Jazz bass pickups arrive yesterday. Their going in my American pro II Jazz V and the Fralins will be here Sunday or Monday and will be going into my last American Pro jazz V.

great info. I wonder if anyone else makes replacements for the American Precision 5. (?)

 

[thmsjordan]

View attachment 4384933
Mine was silent, I wonder how Fender does it?

Mine too. I am pretty happy with the performance of the series II pickups in mine so far.

 

[micguy]

How does the pole piece have an effect if it isn't magnetized?

It's iron - it's magnetic, even if it doesn't have a magnetic charge on it. The inductance of a coil goes up dramatically when you put iron (or other ferromagnetic stuff) in it. Inductance is the ratio of how much field you get from a given current in a coil (technically, this is partial differential equations but we'll blast past that). In our case, we're interested in the reverse - how much current is induced by a given amount of external magnetic field, which is again governed by the inductance. When you change the inductance, you change the amount of hum induced in a coil. Get the inductance the same (you need the 6th pole piece (or set of pole pieces to do that), you get equal hum in each half. Subtract equal amounts......you get zero net hum.

 

[thmsjordan]

There are many asymmetric P5 pickup sets that are sufficiently hum-cancelling. And every J5 split-coil marketed as hum-canceling is asymmetric — as are quad-coil MM and split-coil soapbar 5s. Technically, yes, there is an issue, but in practice, they seem to work just fine.

This is my experience as well.

 

[Kro]

It's iron - it's magnetic, even if it doesn't have a magnetic charge on it. The inductance of a coil goes up dramatically when you put iron (or other ferromagnetic stuff) in it. Inductance is the ratio of how much field you get from a given current in a coil (technically, this is partial differential equations but we'll blast past that). In our case, we're interested in the reverse - how much current is induced by a given amount of external magnetic field, which is again governed by the inductance. When you change the inductance, you change the amount of hum induced in a coil. Get the inductance the same (you need the 6th pole piece (or set of pole pieces to do that), you get equal hum in each half. Subtract equal amounts......you get zero net hum.

Thank you for that, it's fascinating.

 

[micguy]

Thank you for that, it's fascinating.

You're welcome. I'm that kid that, in school, actually liked word problems. So I did them for a lot of years.

 

[iiipopes]

The bottom line is that everyone has spent three pages to discuss that a 5 string P pickup is not optimal for humbucking.

 

[Bassamatic]

Now that is a totally new thing on me! What ends up with that crosstalk, though? I suppose it's not destructive interference, right?

Even with a regular P there would be some crosstalk causing phase cancellation issues, BUT Leo reversed the magnet polarity on one half of the P pickup as well as the coil phase, so the crosstalk is cancelled as well as common-mode noise pickup! Some great engineering there. Surely the 5-er pups do the same thing.

 

[Kro]

Even with a regular P there would be some crosstalk causing phase cancellation issues, BUT Leo reversed the magnet polarity on one half of the P pickup as well as the coil phase, so the crosstalk is cancelled as well as common-mode noise pickup! Some great engineering there. Surely the 5-er pups do the same thing.

This is all great food for thought. In thinking about this though, if the "crosstalk" isn't additive with the reversed polarity on the other side, wouldn't it then be subtractive? Meaning that the strings effected would actually be slightly quieter than they would otherwise?

Perhaps I've completely missed the concept here.

 

[Riff Ranger]

If Duncan's long coil version of that pickup is any indication, then it's a 6-string pickup with a 5-string cover. They actually sent me one at first, and I had to send it back. I said it needs a 3/2 coil set but didn't specify one was normal and one was longer, unlike the Aggie. But the guy at Duncan was very cool about it and he thought they came long/short, too. Unfortunately I had to wait thru the 6 week rotation again, but I wasn't going anywhere so I didn't care.

I guess this changes my plans to use EMG pots and jack. I can't solder worth a crap, especially on pot ground wires. Looks like I'll have to, though.

I tried a 6-string EMG P6X in place of a EMG P5 in the hopes that it would beef up what seemed like an anemic A string on a reverse-P/J 5 with ~18mm spacing (I ran the idea by the excellent folks at EMG, and we all thought it was worth a try). I ended up preferring the P5 of the two after all; as it turns out, this instrument just requires an exacting setup. If the instrument doesn't sell (as you may recall, I have my eyes on a Yamaha BB735A myself), I might contact EMG and see if they'll make me a 5-string set of Geezers. (I'd have thought you might have tried that! ) (In any event, I have an EMG P6X if anyone has an interest ) (I can't solder, either )

Pertaining to your original question: a long and mildly testy tangent on this very subject arose on my "why are 5-string Ps so rare?" thread a while back; you could dig through that if you've got some time on your hands. I'll get caught up on your thread here now.

 

[sunbeast]

The bottom line is that everyone has spent three pages to discuss that a 5 string P pickup is not optimal for humbucking.

Not really- just that that particular 5-string design (one coil shorter than the other) isn't optimal. The design that utilizes equal sized coils with a "dummy" pole or two on one side of the pickup works just great and as noise-free as most standard 4-string P pickups (in my experience with both). The 5-string split-coil J pickup on the other hand is a design that is never optimal for humcancelling as there is no way to get that same "dummy pole" arrangement or use equal-sized coils because of the small size of the pickup. Either way, the trade-off is probably worth it because it is still the closest way to get single-coil type sound with decreased noise.

 

[sunbeast]

I tried a 6-string EMG P6X in place of a EMG P5 in the hopes that it would beef up what seemed like an anemic A string on a reverse-P/J with ~18mm spacing (I ran the idea by the excellent folks at EMG, and we all thought it was worth a try). I ended up preferring the P5 of the two after all; as it turns out, this instrument just requires an exacting setup. If the instrument doesn't sell (as you may recall, I have my eyes on a Yamaha BB735A myself), I might contact EMG and see if they'll make me a 5-string set of Geezers. (I'd have thought you might have tried that! ) (In any event, I have an EMG P6X if anyone has an interest ) (I can't solder, either )

Pertaining to your original question: a long and mildly testy tangent on this very subject arose on my "why are 5-string Ps so rare?" thread a while back; you could dig through that if you've got some time on your hands. I'll get caught up on your thread here now.

I have the P5 in a 4-to-5 conversion PJ bass with 17mm spacing and it sounds fantastic and very balanced, but you are right that the setup tolerances with wider spacing could prove problematic. Nordstrand makes a few P5 pickups in different spacings you might consider for a passive option.