Wiring issue -- hum in bridge/middle position with STK-S4 and TB-4

[David Garner]

Hello all. I have used the following diagram to wire up an HSS Strat pickguard with a TB-4 in the bridge and STK-s4s in the middle and neck. The middle STK-s4 is a proper middle pickup, reverse wind, reverse polarity, and cancels hum properly in the neck/middle position. Here is the diagram.

https://www.seymourduncan.com/images/wiring-diagrams/2STK_SCH_S5W_1V_2T.jpg

I wonder if I don't need to reverse the black and red/white leads on the TB-4 to get proper polarity? Any advice is much appreciated.

 

[PFDarkside]

Do you have enough lead length to swap the middle/neck pickup positions?

 

[David Garner]

I think so -- I didn't consider that. I'll give it a whirl. Worst case I'll have the same problem I have now, right?

 

[David Garner]

Okay, so that didn't fix it, but something worse is going on now and I can't for the life of me figure it out. I swapped the neck and middle again to get back to normal, only now the bridge pickup sounds out of phase by itself. I can't figure out how that could possibly happen unless I wired the superswitch wrong, which I triple checked I did not. But for whatever reason, the bridge alone sounds exactly like the bridge/middle, only the middle pickup is not engaged and both coils of the humbucker are active. Worse, I don't know the difference between parallel wiring and out of phase, so I don't know which I've done and I don't know how to describe what's happening other than as above -- it sounds like Sweet Home Alabama on the bridge pickup alone.

I still have red and white together, green to ground, black to hot. Is it possible some loose solder got into my switch and messed things up?

 

[jeremy]

it is possible that you dripped solder some where but you should be able to see it. do you have a meter?

 

[David Garner]

I do, but I already wired in a normal 5-way switch. Everything is back to normal, so the good news it isn't the pickup itself -- it works fine.

I think I need to decide whether to wire in another super switch or just stand pat with the 5-way and use a mini toggle to split the coils on all 3. I'm a little torn on which way to go there, but I have time to worry about it. I still need to get the neck finished on this guitar.

 

[Jack_TriPpEr]

Hello all. I have used the following diagram to wire up an HSS Strat pickguard with a TB-4 in the bridge and STK-s4s in the middle and neck. The middle STK-s4 is a proper middle pickup, reverse wind, reverse polarity, and cancels hum properly in the neck/middle position. Here is the diagram.

https://www.seymourduncan.com/images..._S5W_1V_2T.jpg

I wonder if I don't need to reverse the black and red/white leads on the TB-4 to get proper polarity? Any advice is much appreciated.

This other recent thread with a similar question says that the middle STK has a South up magnetic polarity (cuz its RWRP) while the other STKs have a North up polarity. Ref: https://forum.seymourduncan.com/foru...-rwrp-polarity

If the Neck and Middle is not producing hum but the middle and bridge is, i recommend that the OP measure the magnetic polarity of the TB-4 to verify that the magnet hasn't been flipped - whether done previously intentionally, or it came from the factory from like that as an oddity or the Guitar Manufacturer's request to SD if the pup was OEM on that guitar. TB-4 Screw coil should be South magnetic polarity, and Slug coil should be North.

Here's a How-To video for checking magnetic polarity of each coil in a Humbucker using a compass. That section starts at about 12 minutes 45 seconds into the video. Most of the other content of this video is about how to measure other specs on a humbucker using a multimeter. Definitely worth studying that other content for another day.

If the TB-4's two coils polarity is opposite of what is normal, I would recommend the OP go ahead and do the other multimeter based tests in the video to check if the TB-4 is also Reverse Wound, meaning the pup is actually RWRP setup. Whether its RWRP setup or just mag flipped makes a difference on the how the wires need to be swapped around on the TB-4. If it's full RWRP, just swap Green and Black wires with each other. If it's just a mag flip, swap Black with Red, swap Green with White, and Green and Black become the nee joined pair of wires.