JB Junior pickups for a Strat

[Darryl Hebert]

I have a peculiar issue. I'm mainly a keyboard player, and secondary guitar player. If I'm playing both instruments in a song, I'll usually play all my keys parts with my left, so I can keep my pick in my right hand. Of course unless it's gnarly solo time, then it's pick down and right hand on keys.

I use mainly Nord keyboards (stage 3's). They're the only keyboards in my arsenal with UNSHIELDED power supplies. Very annoying. Put any electric guitar or bass pickup within 1.5 feet of any model Nord and loud electrical noise comes through the guitar or bass amp, totally unusable. It's a well documented issue with most if not all Nord keyboards. If I have to sing with an electric guitar in my hands I'll try to turn sideways and put my body in between the guitar and keyboard to shield the pickups from the magnetic waves coming from the Nord power supply. Stupid really. In the Nord forum the only solution they've come up is to remove the whole power supply from the Nord and put it in a metal box on the floor (4 feet away).

Here's the thing, I have 10+ guitars, ranging from Tele & Strat single coils, PRS with humbuckers, Les Paul humbuckers. They all have the Nord proximity noise issue, EXCEPT for the JB Jr bridge pickup I put in my new Red Strat professional. That guitar is silent when next to the Nord using that JB pickup.

There is something in the wrapping of the JB Jr's pickups that shields it from the unshielded Nord power supply. I'd love to wrap ALL of the pickups in my other guitars in the same method if that prevents the electrical noise. My 1960 true historic Les Paul has to keep it's original pickups, so I'm not going to swap them out with Duncans. It's my favorite axe. I did just order a whole parchment color trio set of JB Jr's for my sunburst Strat.

Any geniuses out there? Is it in the outside covering, or the pickup electronics that is shielding the JB jr.?

Many thanks!

 

[idsnowdog]

Re: JB Junior pickups for a Strat

The JB Jr is a humbucker which cancels hum by phase cancelation but there might also be shielding around the coils to keep out RFI which may still be present in your full sized humbuckers unless they have a metallic cover which is grounded. The wiring in your humbucker guitar's control cavity might not be shielded so that may be where you're picking up the RFI. Another thing to keep in mind is the JB Jr has a narrower sensing window which might not pick up the majority of 60 cycle RFI from your power supply except at certain angles because 60 cycle is a longer wavelength.

There are a number of different ways to shield a guitar such as conductive paint and metallic foil. Basically what you are doing is creating a farrady cage around the electronics and then grounding the shielding to remove the noise from the circuit. Otherwise, the guitars circuitry acts as an antennae which picks up the RFI from your keyboard's power supply.

To remove hum from a single coil guitar like a strat you can braid/twist the wires from the pickups which is a form of phase cancelation, keep the amount of wire used short, and shield the pickguard with foil and ground it. I use StewMac graphite paint which is messy but after 3 or 4 coats creates a seamless conductive cavity which only needs one ground wire. I create an area about 1/2 inch wide outside of the guitar pickup routes where the foil from the pickguard can make contact with the grounding paint to complete the circuit. You can reduce the amount of RFI in a single coil guitar by quite a bit but not completely eliminate it unless you use a dummy coil which is still phase cancellation.

 

[Darryl Hebert]

Re: JB Junior pickups for a Strat

I knew there would be someone smart enough hanging out in these forums...thx for the response!

 

[idsnowdog]

Re: JB Junior pickups for a Strat

Couldn't you just take a three prong power cord and splice a standard two prong adapter on the end and then a crimp on grouding ring on the common ground and then screw it into the power supply where the 3 standoffs secure the power supply at the bottom? I would think that would ground the power supply and the chassis?

 

[Darryl Hebert]

Re: JB Junior pickups for a Strat

The Nord Stage 3's take a standard three prong power adapter. The picture in your post looks like an old style Nord power supply (they used to be two prong). I may be out in left field here, but I don't think it's a grounding issue. The Nord unshielded power supply is emitting RFI that electric pickups absorb.