I am about to upgrade the pickups in my Ibanez 1527 7string guitar, so I was looking into this model for the bridge: Seymour Duncan JB Modell 7 Bridge black 4-phase, 7-string. Could someone explain what "4-phase" means? I would like to avoid buying the wrong pickup.

2 Answers 2


I think this means 4 conductor which gives you the option of wiring the pickup to a switch so that you can use it as full humbucker (with both coils) or as a single (just using one coil). You can just hardwire it without a switch in full humbucking mode if that is all you need.

Some pickup manufacturers produce their pickups with both 2 & 4 conductor wiring. 2 conductor will only allow you to have the humbucker option, but simplifies the wiring a little.


Looking at the specs for the Ibanez 1527 it has a 5-way switch which allows you to get both single coil and humbucking tones, so yes, you will need four-conductor wiring on any replacement pickups if you want to keep the range of sounds you have currently. Looking on the Seymour Duncan website a wiring diagram you could use is:


It might be worth looking on the Ibanez website as they may publish the exact wiring diagram for your guitar (I had a quick look but could not see it), or you could try e-mailing them.

If in doubt, get a competent guitar tech to install the pickups for you. Hope this helps.

  • Thanks for this explanation. Would there be any disadvantages from using a 4 conductor mode vs 2? My guitar is HH (ibanez rg 1527) and I am looking forward to the sound of the 2 coils in the humbucker, but would there be an option to switch between 1 and 2 at the distance of a switch? is that what you mean?
    – CaseyJones
    Commented Mar 12, 2013 at 9:40
  • I have updated my answer, but in summary it looks like you DO need 4-conductor wiring on your replacement pickups.
    – Paulski73
    Commented Mar 12, 2013 at 11:18
  • @CaseyJones: IIRC there is info on the SD website about "splitting a humbucker" aka coil split or coil tap. From the answer, it sounds like your guitar's wiring already deals with this, but it is possible to add a toggle. I added one to an (HSS) Strat. Took about 3 mins.
    – horatio
    Commented Mar 13, 2013 at 19:20

I'm looking around at different sites and I'm not seeing four-phase as a description anywhere.

What I do see is that they have signal and ground from both coils. From there, you can do signal from one coil or the other, or both coils in serial or parallel.

I don't know how you play, so I don't know what the right pickup for you would be, but Seymour Duncan is one of the bigger and more trusted names in pickups, and the JB pickup is one of their flagship models, so I would suspect that this pickup would be decent for you.

  • Thanks, I had this pick up in the past in one of my 6 string guitars. I know it sounds great and I'm looking forward to it. The 4 phase is written in the pickup description.
    – CaseyJones
    Commented Mar 12, 2013 at 9:37

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