Mini Humbuckers - options / experiences?

[Artie]

But he stuck to his guns so I wired up a push pull and the parallel measured a good old 1.5k ohms... I was preparing my sinister "I told you so" laugh, I plugged it in and I was totally knocked out by the parallel to self.

I wish I could get people to stop making reference to DCR of coils in parallel. It's meaningless. You're simply tricking the internal circuitry of your meter. Take a Vintage Rails. Its DCR is 2.5k. But it has the voltage output of a 5k coil. (Two, actually.) Because that's what it is. Two AA batteries in parallel have the exact same voltage as one by itself.

I'm done.

I always prefer parallel to split coil. It gets that clean bright tone with no hum.

Exactly.

 

[zionstrat]

Artie,
We've had this conversation before and I wish I understood things better.. My brain perceives circuits as plumbing which means I either find an EE course for pickups or I can continue to make decisions based on this is connected to that + experience ... Maybe it's time for you to write a modern book about pickups

So let's drill into this a little deeper if you don't mind. Two coils in parallel usually sound as if there is less output then series. I get the idea that the voltage is the same so where do we measure the difference?

I understand that DCR is only useful comparing length of wire in coils that otherwise are exactly the same. And I also understand that inductance is the best way to ultimately measure a pickup...

And I also understand why my customers tend to be more happy with parallel as opposed to series coils.. humbucking is a great advantage and there is a bit of added complexity to the signal because no two coils are exactly the same. And it may be that complexity, however in the mix it seems that parallel is a little louder than a coil cut.

But how do you measure any of this? My customer was asking for parallel because he's heard the results on many other pickups. But in my mind 1.5 kohms was far too low to produce a reasonable result and I know a lot of other modders who have said exactly the same thing.

In your example, voltage doesn't change but the sound is considerably different. So what measurement could I have been using that would have predicted that a 1.5 parallel on a mini would produce sufficient volume to be useful?

Thanks for any and all input as always!
Michael

 

[Artie]

But in my mind 1.5 kohms was far too low to produce a reasonable result and I know a lot of other modders who have said exactly the same thing.

Hey zion; This is difficult to explain in a "sound bite." Which is what a forum post effectively is. It isn't 1.5 k ohms. That's the misinformation your meter is conveying to you because you're confusing the meter circuitry with a parasitic electrical path. (The "other" coil.) Both coils are producing the same voltage. So you have twice the current capability to "drive" the load of the volume and tone circuits. The perception of lower output is coming from the fact that both coils are picking up slightly different string nodes. Therefore, you'll get a degree of phase cancellation at certain frequency points. But, you'll also get certain frequency augmentation at other points. It's kinda like the sound of the neck/middle of a Strat. That sound is often mistakenly interpreted as being weaker, or out-of-phase, when in fact, it isn't. It's just the way our ears, and brain, interpret the sound.

Let me see if I can explain this better in the morning. With coffee.

But remember . . . you were surprised by how good it sounded. It's approximately the same output, but harmonically more complex.

 

[freefrog]

Artie,

So let's drill into this a little deeper if you don't mind. Two coils in parallel usually sound as if there is less output then series. I get the idea that the voltage is the same so where do we measure the difference?

I understand that DCR is only useful comparing length of wire in coils that otherwise are exactly the same. And I also understand that inductance is the best way to ultimately measure a pickup...

Hi,

I can't talk for Artie but if I can add my humble two cents to his explanations above...

You already have a part of the answer to your question, IMHO: wiring coils in parallel divides their inductance more than it does with DCR (because of mutual inductance).

This change shifts up the resonant frequency of the pickup. It locates its 'peak power" (resonant peak) higher in the audio spectrum...


Below is an example.

http://kenwillmott.com/blog/wp-conte...omparisons.png

Green and blue lines come from the same (blades) humbucker wired in series and parallel with a 220k load (= roughly two "low DCR" 500k pots).

I wish the author of this test had not filtered the result by converting voltage to current, because it hides the resonant peak in series in this case. I also wish he had mentioned stray capacitance... but this missing info doesn't hide what happens with parallel wiring: it rises the resonant peak of approximatively 2000hz and lowers the output of +/- 2dB:

I've similar tests in my archives but am too lazy / busy to search them right now. LOL.

So what measurement could I have been using that would have predicted that a 1.5 parallel on a mini would produce sufficient volume to be useful?

Inductance and Gauss readings. At least that's how we do it here.

It's also possible to estimate what Artie mentions above: how a pickup in parallel captures differently vibrating strings by creating a different comb filtering effect. Here is a useful applet about that:

http://www.till.com/articles/PickupR...emo/index.html

If we select two pickups and locate them virtually with the same gap than between two coils in a humbucker, we'll see what it does compared to one single wide virtual pickup (simulating itself a series humbucker).

Now and if you ask me: none of these measurements or simulations is able to show exactly what a specific pickup does in a defined guitar. If the lutherie creates acoustic dead spots, a pickup will interact with that in a necessarily unpredictable way IMHO/IME.

That being said just to share my indifferent thoughts. Hope it helps to some extent.

Oh, and... like several fellow members above, I tend to prefer parallel compared to split coils. I also agree with the interest of a mini HB as a neck pickup in a Tele. I've recenty worked on a Squier like this, whose Duncan Designed neck mini HB sounded surprisingly good to my ears:

https://images.reverb.com/image/uplo...ji6oevzbb5.jpg

 

[zionstrat]

Wow, Artie and Freefrog! After all of these years, I think you guys just threw enough acorns into the conversation so that the blind squirrel can pick up a couple

If I am understanding the graph correctly, the green line series average is about one and a half DB above the parallel blue line in the mid-range and bass range. However the blue line has a significant increase around 1 DB at 5K.

So if I'm understanding this all correctly, although the energy is the same for both, most of the series signal falls right in the middle of our ears sweet spot so we perceive it as a loud sound.

And if I've got that correct, then the blue parallel curve is demonstrating that reduced output in that same mid-range range so we hear it as quieter. However that spike up at 5K might be part of the reason that parallel often has a bright shimmering quality and helps it sit well in the mix.

So, assuming I've got that right I would just love to see what a coil split would look like.

Thanks again guys. Very very interesting!

 

[freefrog]

If I am understanding the graph correctly, the green line series average is about one and a half DB above the parallel blue line in the mid-range and bass range. However the blue line has a significant increase around 1 DB at 5K.

So if I'm understanding this all correctly, although the energy is the same for both, most of the series signal falls right in the middle of our ears sweet spot so we perceive it as a loud sound.

And if I've got that correct, then the blue parallel curve is demonstrating that reduced output in that same mid-range range so we hear it as quieter. However that spike up at 5K might be part of the reason that parallel often has a bright shimmering quality and helps it sit well in the mix.

That's how I could word it too - without forgetting what Artie said about coils capturing different "nodes" of the vibrating strings (as illustrated on request by the admirable Tillman applet).

So, assuming I've got that right I would just love to see what a coil split would look like.

A HB in single coil mode should set between series mode and parallel wiring, when it comes to resonant frequency AND (electrical) output. Reason: the inductance is only halved in single coil mode.

Please, note that results should or might differ under vibrating strings because of the actual "magnetic windows" (strings reading windows) involved in both cases.

Thanks again guys. Very very interesting!

You're welcome. It's always a pleasure to share something here (and it's a very minor contribution compared to ALL what Artie has generously shared on this forum until now).

 

[Artie]

You're welcome. It's always a pleasure to share something here (and it's a very minor contribution compared to ALL what Artie has generously shared on this forum until now).

Thanks for the kind words freefrog, but I think you actually nailed the technical part better. It was late, and I was tired, last night. I was probably a little too succinct to be clear. Or helpful.