Bartolini 9J1 L/S pickups

BSOD · #1 01-04-2009, 12:11 AM

Hi all,

This is a bit of a repost, I hope no one objects.

I recently purchased a set of Bartolini 9J1 L/S pickups for my Squire VMF bass. These are a dual coil pickup according to the packaging. I have installed them and am still experiencing some hum issues. One thing I am confused about is that from what I have seen on some wiring diagrams, dual coil pickups normally have more than two leads, yet the Bartolini's I have only have two leads on them, the active and earth. Does this mean I was shipped the wrong pickups or is this because they are a spit or stacked coil design?

Also, can anyone recomend a good series/parallel diagram. Ive seen the diagrams on Semour Duncan's website and one from Rothstein Guitars. Their wiring diagrams are slightly different and I am not sure if one is better over the other, so any guidance would be greatly appreciated.

Regards

Craig

sunbeast · #2 01-05-2009, 04:08 PM

The Barts are dual coils, the coils are just hardwired on the inside. I'm not sure if they hard-wired them in series or parallel. Any series/ parallel diagram should work equally as well, though you could possibly get some extra noise with the Barts wired in series (I never tried it with mine), as the grounding for the pickup is hardwired through the "earth" connection and will be lifted on one pickup when they are in series. It may or may not be noticeable...

Karl

BSOD · #3 01-06-2009, 03:01 AM

Hi Karl,

thanks for the reply. I was just a little confused. Most (if not all) of the dual coil pickups I've seen have more than one active and earth lead on them whereas the Barts I have only have a single active and earth which is what the old single coil pickups had. I was concerned that I was not supplied with the dual coil/spit coil pickups.

I've already tried the series/parallel wiring based on the Seymour Duncan diagram. Still lot's of hum though and the tone control is hardly noticeable. The Squire originally used 500K pots, but I replaced them with 250K pots as per instructions that came with the Barts. I might try putting the 500K pots back in. Not sure why I have so much hum though.
All of the earthing seems fine.

Craig

BruceWane · #4 01-06-2009, 02:55 PM

9J's are a split coil design.

Yeah, it is still technically a "dual coil" since there are two coils, but you really can't do coil splitting like you do with a traditional side-by-side dual coil pickup, or coil "tapping"* like you do with a stacked coil pickup.

*technically, not really coil tapping but coil splitting to remove the bottom coil from the circuit. It just looks a lot like coil tapping because of the layout of the pickup.

As far as I know, Bartolini doesn't do any stacked coil designs for bass at all. Only split coil and dual coil.

You can see the internal coil layouts for all of Bartolini's stuff here....

9J's aren't as flexible as some other designs, but they're still very nice pickups. I've got a pair of 59J's in a Modulus Genesis, love 'em.......

sunbeast · #5 01-06-2009, 08:05 PM

The reason alot of "dual coil" or "split coil" pickups have 4 wires is so that you can make the choice to wire the coils in series or parallel, which has a noticeable effect on the tone- Bartolini hardwires the coils in either series or parallel (not sure which) rather than giving you the option. Same difference though, as they are hard wired on the inside, so you can't really play around with series/parallel with the different coils like you can with Dimarzio Model Js, for example. I'm pretty sure that Bartolini doesn't offer the 4 conducter wiring option on any of their pickups. They should both have 9J1 etched into the bottoms.

Karl

BSOD · #6 01-07-2009, 04:51 AM

Hi Sunbeast. Well that explains the wiring then. Thanks for clearing that up. I'll just go over and recheck all the ground points to try and clear up the hum.

Craig

sunbeast · #7 01-07-2009, 04:04 PM

Also, as I said in my first post- I'm not sure what kind of internal pickup shielding Bartolini uses, but it will also be hardwired to the "earth" connection from the pickups. When you wire 2 pickups in series with each other, you are lifting one of these ground connections and instead making the shielding part of the signal path in one pickup. Again, not sure if thats applicable with Bartolinis, but it could be why you are experiencing excess noise in the series setting. If this is the case, then maybe Bartolinis are not really compatible with series Jazz wiring...

Karl

BSOD · #8 01-07-2009, 06:33 PM

Hi Sunbeast,

hmm, that's a good point and to be honest, one I hadn't considered. Perahps I'll just stay with standard jazz wiring or look at other pickup alternatives. Thanks for you comments.

Craig

sunbeast · #9 01-08-2009, 03:25 AM

Yeah- I would think Bartolinis wouldn't be the best choice tonally for a series wiring modification anyway. They are already pretty dark sounding, which would just be intensified in series. I've had the best luck wiring really bright single coils in series, which tends to give a really P-bassy midrange sound. I had a bass with Dimarzio Model Js (also split-coil J pickups) and had a series/parallel switch- I just found the series setting to be too muddy with pickups that are already pretty dark sounding.

Karl

basadam · #10 01-08-2009, 05:13 AM

So, BSOD,

What's your impression about 9J1s? I'm contemplating to order a set coupled with J-Retro for a Lakland Darryl Jones. My goal is something that does not sound like a J-bass, and the term "dark sounding" intrigues me. I tried Model Js for the same reason but didn't like them.

niftydog · #11 01-08-2009, 05:24 PM

Take a look at the bottom of the pickup and you should see three metal lugs poking out - two of them will be soldered together with the braid of the cable. One of those lugs is one end of the pickup coils themselves - the other one is a metal shield that encases the coils.

Wiring in series requires you to remove one end of one of the pickups from ground and reconnect it to the other pickup - in the case of 9J1's this also means that the metal shielding becomes disconnected from ground (and becomes part of the series circuit) which is not ideal if you're having hum issues.

I got rid of the stock wiring and soldered in a wire for each lug - Then I wired the metal shields of both pickups permanently to ground then do whatever I want with the coil switching.

To find which lug is which, measure the resistance between the lugs - a low-ish resistance between two lugs (say around 5-10k ohms) will be the coils. The one lug that reads open circuit to both the other two lugs is the metal shield.

BSOD · #12 01-08-2009, 06:11 PM

Quote:

Originally Posted by basadam

So, BSOD,

What's your impression about 9J1s? I'm contemplating to order a set coupled with J-Retro for a Lakland Darryl Jones. My goal is something that does not sound like a J-bass, and the term "dark sounding" intrigues me. I tried Model Js for the same reason but didn't like them.

Well I'm a little hesitant to say too much until I get the wiring right, however at first glance to me they sound punchier than the stock SD designed pups the squire came with. Once I have the wiring sorted out I'll be in a better position to comment. Sorry I can't say more than that.

Craig

BSOD · #13 01-08-2009, 06:15 PM

Quote:

Originally Posted by niftydog

Take a look at the bottom of the pickup and you should see three metal lugs poking out - two of them will be soldered together with the braid of the cable. One of those lugs is one end of the pickup coils themselves - the other one is a metal shield that encases the coils.

Wiring in series requires you to remove one end of one of the pickups from ground and reconnect it to the other pickup - in the case of 9J1's this also means that the metal shielding becomes disconnected from ground (and becomes part of the series circuit) which is not ideal if you're having hum issues.

I got rid of the stock wiring and soldered in a wire for each lug - Then I wired the metal shields of both pickups permanently to ground then do whatever I want with the coil switching.

To find which lug is which, measure the resistance between the lugs - a low-ish resistance between two lugs (say around 5-10k ohms) will be the coils. The one lug that reads open circuit to both the other two lugs is the metal shield.

Ok I'll have a butchers tonight, but from memory I thought the cables just dissapeared into the pickup case. I don't recall seeing any exposed lugs. If they are exposed as you suggest then I do like your wiring idea and will give it a shot.

Craig