Duncan JBL 13.7 kOhm DC-resistance

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Axewall

New member
Hi folks! Got myself a strange Duncan JB the other day, only 13.7 kOhm DC-resistance! It's long-legged with "Seymour Duncan" on top of the adjustable bobbin and a small sticker at the bottom with "JBL" on it. I know the "L" stands for Lidia Daniel. I tried it in my SG Faded, and compared to another new JB I've tried just before I think the JBL doesn't have the pronounced upper-mid spike, it's mellower, but the new JB seems to have more warmth, more bass maybe. The JBL sounds great though, very punchy! I'm thinking,, could this be a different SD pickup with the wrong label?
 
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Re: Duncan JBL 13.7 kOhm DC-resistance

Welcome to the forum.

13.7kOhms is certainly out of tolerance for the SH-4 JB model and, strangely, any of the other current Seymour Duncan production line humbucker range.

Three obvious questions need asking:
1) How accurate is your multimeter?
2) What evidence do you have that the pickup really is a JB and not, say, a misdescribed Custom Five?
3) If the pickup came to you pre-owned, is there anything about its appearance to suggest that it might have been modified by the previous owner?
 
Re: Duncan JBL 13.7 kOhm DC-resistance

Another thought.

Your quoted DC resistance figure of 13.7kOhms is for both coils connected in series. If your pickup has four conductor plus shield cable, take readings for the individual coils. It would be interesting to know what the respective values are for each coil.
 
Re: Duncan JBL 13.7 kOhm DC-resistance

Thanks for the welcome, Funkfingers, and your answers. 1) My multimeter is very accurate, and the new JB measures 15.9k in parallell with 500k volume pot (it's in a friends Vintage LP copy now) and when calculated the new JB is 16.4k. 2) No "evidence" at all. The bottom of the plate has got some wax on it and it partially covers the JBL sticker. The sticker is also half-loose, like it's only fastened by the wax. 3) I didn't inspect it that much when I got it as I was very eager to give it at test in the SG.

But! Today I'll pluck it out and check it for possible signs of modifications. And I will measure the two coils separately, good thought!

Is there any way to tell if it's got an Alnico or Ceramic magnet?
 
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Re: Duncan JBL 13.7 kOhm DC-resistance

Axewall said:
Is there any way to tell if it's got an Alnico or Ceramic magnet?
Click to expand...

if it's really dark ie nearly black it's ceramic, if it's shiny it's alnico
remember to scrape the wax/resin/glue/blue off though ; ]
i can't tell the grades apart, it's impossible AFAIK.

you'll be able to tell further but it'll involve carefully peeling tape back to see what colour the wire coils on the bobbins are, and scraping wax off the baseplate so you can be certain on this sticker, and any other markings on the baseplate
i've never owned a duncan that had epoxy all over it, they're just potted on the baseplate and around the mag and lead wires... i'd expect 2 black/white pairs going to black/red/white/green/bare cable in this instance
baseplate will likely be stamped

i had a JB with purple wire on it, the custom's wire coils looked yellow.

enjoy!
 
Re: Duncan JBL 13.7 kOhm DC-res. Now with pics!

Re: Duncan JBL 13.7 kOhm DC-res. Now with pics!

Thank you for your answer, dr. ad! Maybe I'll strip the JBL tomorrow...
Today I got it out of the SG and I measured it again, this time it was 14kOhms. It was a more accurate reading, using clips on the leads and not holding them together using my fingers. North coil was 6.8k, south coil 7.2k and in series 14k. As said before that's more like Custom, Custom Five or Custom Custom. Here's pics of the JBL:
The slits in the screws are narrower than on a new JB and a new '59 I've got
View attachment 15891
The half-loose JBL sticker
View attachment 15892
The small rectangular holes are bigger than on a new JB and a new '59 I've got
View attachment 15893

I'm thinking of getting in contact with Maricela Juarez by e-mail, does any of you guys have her adress? My e-mail is hemmanet(at)gmail(dot)com.
 
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Re: Duncan JBL 13.7 kOhm DC-resistance

definitely a duncan, from the look of it... if it meters 14K i'm thinking it's a custom of some sort but the JBL sticker's thrown me off; did you buy this used? i'm thinking that somewhere out there there's a JB with a custom sticker on heh heh
 
Re: Duncan JBL 13.7 kOhm DC-resistance

dr. ad said:
definitely a duncan, from the look of it... if it meters 14K i'm thinking it's a custom of some sort but the JBL sticker's thrown me off; did you buy this used? i'm thinking that somewhere out there there's a JB with a custom sticker on heh heh
Click to expand...
Yep, bought it used. I'm having the same thoughts, that maybe a JBL sticker fell off a JB in the wax bath and was later attached to the wrong pickup. Judging from the way the JBL sounds compared to the newer JB I'm beginning to think it might be a Custom Custom. No pronounced mid spike, not very bassy, and not very trebly. Fits the CC's tone chart readings. Havent heard a CC myself. Oh, and I've got MJ's e-mail address now!
 
Re: Duncan JBL 13.7 kOhm DC-resistance

Sometimes people swap baseplates if one was drilled out for direct mounting, or if they wanted a short/long legged baseplate, etc.

I doubt it's some kind of manufacturing error, marking a Custom with a JB label.
 
Re: Duncan JBL 13.7 kOhm DC-resistance

Today I stripped the JBL and guess what? The magnet is black, not shiny! I loosened the screws holding the bobbins and after a little wigglein' I could slide the magnet out. Black, and I could not see any markings on it at all. I also checked the newer JB and a '59, shiny magnets in both! And judging from the looks of the pickup, wax and stuff I don't think it's been modified. Seems like I've got myself a Duncan Custom now! But I'm seriosly thinking about making a Custom 5 of it, I think it would sound better in an SG. Am I right?
 
Re: Duncan JBL 13.7 kOhm DC-resistance

i'd stick with the ceramic custom or put an A2 in there personally, but many swear by the C5. could be quite cool in an SG

Frank - didn't think of that, that makes a lot of sense. i just thought perhaps the previous owner had put a different sticker on there for some reason heh heh
 
Re: Duncan JBL 13.7 kOhm DC-resistance

I think it's a CC, I'm sure it matches close to the readings I got from mine recently. Great pup!
Don't turn it into a C5 yet, try it as it is. I must admit I loved the C5 in my Epi SG, but why tinker with something until you're sure you don't love it?
 
Re: Duncan JBL 13.7 kOhm DC-resistance

Thank you guys for elaborating(?) on this (well, just hit me if I use the wrong words or phrases). Could not be a CC, it's gotta be a C with this ceramic magnet. Been playing it some more now and I think it sounds too thick for my taste, gonna try a conversion to a C5 today. An A2 would make it a CC, I can try that too.
 
Re: Duncan JBL 13.7 kOhm DC-resistance

Took a A5 from a 498T and put in the...well, can I call it a Custom now? I think we've come to the conclusion that it's NOT a JB. Anyhoo, it didn't sound good at all, very scooped mids and harsh highs, ok lows though. If this is how a Custom 5 sound like I don't get it. Gonna try an A2 from a 490R tomorrow, making it sorta CC.
 
Re: Duncan JBL 13.7 kOhm DC-resistance

Axewall said:
Took a A5 from a 498T and put in the...well, can I call it a Custom now? I think we've come to the conclusion that it's NOT a JB. Anyhoo, it didn't sound good at all, very scooped mids and harsh highs, ok lows though. If this is how a Custom 5 sound like I don't get it. Gonna try an A2 from a 490R tomorrow, making it sorta CC.
Click to expand...

IF it's from the Custom family....:nervous:
 
Re: Duncan JBL 13.7 kOhm DC-resistance

This is what MJ wrote to me when I told her about the magnet, "I knew the magnet would be ceramic since it's an old wind DC, it will be great as a custom 5". Well, she couldn't know me not liking the "C5" sound:-D
 
Re: Duncan JBL 13.7 kOhm DC-resistance

if you didn't like the custom or the C5 in your SG then the A2 is the go
or you could get an A8 and go down that path. apparently those pickups make one hell of a coffee.
 
Re: Duncan JBL 13.7 kOhm DC-resistance

i just seen this post, i have a JBJ with just barely over 14k resistance.. my theory behind this is these are custom made "neck" models that came pre installed in old guitars.. i could be wrong but mine came off a guitar like this stock and it was in the neck position.. i did a post about it not so long ago and i cant seem to find an answer as to why its 14kish so my theory is its probably a "neck" version that was made for certain guitars to come stock with it.. definetly don't like it in the bridge.. doesn't sound quite like a full JB
 
Re: Duncan JBL 13.7 kOhm DC-resistance

C-Martin said:
i just seen this post, i have a JBJ with just barely over 14k resistance.. my theory behind this is these are custom made "neck" models that came pre installed in old guitars.. i could be wrong but mine came off a guitar like this stock and it was in the neck position.. i did a post about it not so long ago and i cant seem to find an answer as to why its 14kish so my theory is its probably a "neck" version that was made for certain guitars to come stock with it.. definetly don't like it in the bridge.. doesn't sound quite like a full JB
Click to expand...
Hmmm....suddenly it seems more complicated again, it was turning out to be simple, but.... :-) Have you ever checked your theory with Duncan (MJ)?
 
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