Seymour Duncan JB

[PLX]

Anyone have the complete history of the pickup

I've managed to find out it was introduced in 1974.

[lll]

In a nutshell here's what I know from both personal experience and from the Soymore Duncan Forum.

I've been using a JB in some form or fashion since the late 80s.

The JB was arguably *the* pickup of the 80's. Lots of famous pro's used it on countless albums.

And you'd definitely find them in most off-the-shelf Kramers.

Generally speaking, it has a crunchy top, warm mids (excellent for soloing) and a loose bottom.

I believe it's resonant peak is at 6KHz (same as the Shure SM57's upper-mid spike)


Supposedly it was designed by Seymour for Jeff Beck's "Tele-Gib":

https://www.seymourduncan.com/blog/seym ... e-tele-gib

The letters "JB" give away its provenance.

There have been a few iterations, including some "heritage" winds (built like the old ones).

Many people claim a new JB doesn't sound like the older 70s/80s JBs.

My JB is from approx 1988-89 and has the (for whatever reason) vaunted "JBJ" sticker on the back (Maricela-wound).

[PLX]

Does the JB have asymmetric coils ?

[PLX]

I stumbled across this very interesting article from Nov 2016 :

“The JB Model” can mean different things to different people. We are going to talk about the JB model that is literally “The JB Model”. Go back almost 40 years to 1977, when documentation reflects Seymour introduced his first humbucking pickups: the Jazz and the JB.



The progenitor of this late-70s to early-80s The JB Model was a pickup that Seymour was making in London, which was reissued around 2011 as part of the JB/Jazz Concept Set =. The successor to The JB Model would be the JB with 3-digit shorthand code on a smaller label, such as JBJ (see photo).




And yes, you can bet you’ll see a review of that one as well. I’ve had plans for quite a few years now to run through the different iterations of the JB, ranging from what Seymour was first making to what the Duncan company is producing today. At the end of the series, I’ll run through a bit of a comparison.

At the outset, let me clarify that my research has indicated that the wind of the JB has remained consistent. The materials are a bit of a different story, and I promise we will cover all that before we complete this series on the JB.

Let’s take a peek at The JB Model that I have on hand. Double cream (sorry, Larry). Nylon bobbins. Long legs. Wood spacers. Alnico 5 magnet. Four conductor lead wire, although they can be found with single conductor as well. This example has been confirmed by Seymour to be one that he made.

For this evaluation, I installed The JB Model in to the same guitar that had been testing the 59 Model Set, so I left the 59 Model neck humbucker in place. The JB/59 configuration is more common with Jackson Guitars, for example.

Looking down the barrel of an almost 40 year old humbucker, it can be hard to know what to expect. This pickup still has the mojo going on. Part of it could be that it’s wound to a little lower resistance than the other versions of the JB model that I have on hand.

Something else interesting is that there is almost a 17% coil offset in this one, where as all those other JB models that I just mentioned are much more symmetrical.

Hard to pin that one down. Outside of the hybrid model that appears to come from an end user’s idea, the Duncan company humbuckers are known for having pretty well matched coils.

In conclusion, it’s a great sounding pickup. A little more balanced across the EQ than the current production model version. Where as many people complain about the thick lows and ice pick highs of the JB model that’s fresh of the CNC these days, this old The JB Model is a cure for those ills. There is more control on the lows, which can keep your 80s pedal tones from getting too thumpy. The high end has all the bite and presence, but with more sweetness to keep you out of that ice pick territory. And yeah, it’s a JB, so you get the mid-range roar. It’s the sound that launched a thousand hair bands. Ha!

Series Resistance – 15.659 K
Series Inductance – 7.924 H
Slug Coil – 7.138 K
Screw Coil – 8.551 K
Parallel – 3.889 K
Magnet – Alnico 5



Jalen FW spec:
Series Resistance – 15.659 kΩ
Series Inductance – 7.924 H
Slug Coil – 7.138 kΩ
Screw Coil – 8.551 kΩ
Parallel – 3.889 kΩ
Magnet – Rough Cast Short Alnico 5
Lightly potted / no vacuum potting



So, I just unintentionally solved the mystery of where Jim came up with that spec.. This Internet article from Nov 2016 where a guy took apart an old Seymour Duncan JB and posted the spec.

It just so happens to be the exact spec Jim posted for the Jalen FW pickup.

https://darthphineas.com/2016/11/seymou ... -jb-model/

[lll]

Does the JB have asymmetric coils ?

Not that I'm aware of.

[lll]

Series Resistance – 15.659 K
Series Inductance – 7.924 H
Slug Coil – 7.138 K
Screw Coil – 8.551 K
Parallel – 3.889 K
Magnet – Alnico 5



Jalen FW spec:
Series Resistance – 15.659 kΩ
Series Inductance – 7.924 H
Slug Coil – 7.138 kΩ
Screw Coil – 8.551 kΩ
Parallel – 3.889 kΩ
Magnet – Rough Cast Short Alnico 5
Lightly potted / no vacuum potting



So, I just unintentionally solved the mystery of where Jim came up with that spec.. This Internet article from Nov 2016 where a guy took apart an old Seymour Duncan JB and posted the spec.

It just so happens to be the exact spec Jim posted for the Jalen FW pickup.

https://darthphineas.com/2016/11/seymou ... -jb-model/

I'm very familiar with "DarthPhineas"; he used to be a regular on the Soymore Duncan Forum (but left like so many have). Also, he had PM'd me a few times on the Bare Knuckles forum about pickups. He apparently has been doing his own Wordpress blog thing for a handful of years now with pickup reviews etc...

Looks spot on for the specs.

[PLX]

I'm very familiar with "DarthPhineas"; he used to be a regular on the Soymore Duncan Forum (but left like so many have). Also, he had PM'd me a few times on the Bare Knuckles forum about pickups. He apparently has been doing his own Wordpress blog thing for a handful of years now with pickup reviews etc...

Looks spot on for the specs.

Yeah, so this is all starting to make sense now.

I've read many, many comments over the years from people who swear on a stack of Guitar Player magazines that the "JB"s from the 70's were different than the "JB" you can buy today. I remember that freak from MetroAmp.. Plexified He worked at the Kramer factory back in the 80's and would go off on these insane tangents about transformers and magnetic fields.. what a hoot.

He was one that would never let that go, saying the the JB's they were putting in the Kramers back then were wildly different than what you could buy in 2004~2005. He also swore that Ed used a JB model in his black and white Franky for the early records.

Here's what Gaustad says in his video:

"I had the priviledge , or I was lucky to find a couple of examples of it, and I've kinda known about this for a while but I never been able to necessarily prove it. But I've seen some documentation online and, like i said, I've seen a couple of live examples and we put a meter on 'em and the amazing thing is, these original JB's... this was the prototype JB.. probably wound in the mid to late 70's.. before they were available.. you couldn't go to a music store, or a guitar/luthier or whatever and buy a JB pickup back then. There was no "Seymour Duncan Pickups" yet... so this was the first attempt at it. "

Darth Phineas JB specs of 4 examples:

The JB Model ex. #1 (verified to be made by Seymour) [This is also the identical Spec for the Jalen Fair Warning - probably the source]
Series – 15.659 K
Inductance – 7.924 H
Split – 7.138 K
Split – 8.551 K
Parallel – 3.889 K
Magnet – Rough Cast Alnico 5
coil offset : 18.012620307222 %

The JB Model ex. #2
Series – 15.968 K
Inductance – 7.888 H
Split – 8.137 K
Split – 7.861 K
Parallel – 3.995 K
Magnet – Polished Alnico 5
coil offset : 3.450431303913 %

The JB Model ex. #3
Series – 15.717 K
Inductance – 7.757 H
Split – 7.867 K
Split – 7.889 K
Parallel – 3.936 K
Magnet – “Hybrid” Alnico 5

The JB Model ex. #4
Series – 16.165 K
Inductance – 7.746 H
Split – 8.073 K
Split – 8.122 K
Parallel – 4.047 K
Magnet – Polished Alnico 5

[harddriver]

Does the JB have asymmetric coils ?

Alot of people say Seymour mostly did symmetrical winds but like anything else I guess the winder could not be paying attention as some type of happy accident so to say from time to time.

[PLX]

Alot of people say Seymour mostly did symmetrical winds but like anything else I guess the winder could not be paying attention as some type of happy accident so to say from time to time.

Yeah, that was my understanding as well.

The Darth Phineas guy had these comments regarding the disparity between the four early examples of JB's he has:

"Let’s start with the DC resistance. Those examples run a range from 15.717 k to 16.165 k. The coil offset ranges from 0.27% to 16.5%. That can mean different things and should not be an assumption of a secret recipe or other deliberate act. If anything, we should remember that tolerances on materials were not as tight as today. It was about 40 years ago, after all.

Here’s the deal. Matching DCR on two coils of the same humbucker is no guarantee of the coils being identical. Any more that uneven DCR readings might not mean there are more or less turns. How the wire is handled can affect coil geometry, as we should remember these were long before a CNC is put in to play on this model.

As such, there is an array of variances that can come in to play. Did the winding operator load one part of a coil thicker or thinner than the rest? Is one coil made in a Friday afternoon batch and the other made Monday morning after a fresh calibration to the winding machine or new felt for the tensioner? Maybe something is going on with the tolerance of the material that came from the wire vendor in use at that time? There’s no telling.

Why all that detail? It’s funny. One of my The JB Model humbuckers is confirmed to be Seymour’s own work. I get word a while back that some chump is selling one, using the online DCR specs from mine as a launching point to promote their item as also being from Seymour’s hands and asking stupid money for it. Except the seller is dead wrong about who wound it. How do I know? Sorry, that’s my earned knowledge to do with as I see fit."