Middle Position Weak Sound

[Malloc]

Alright I'm normally competent at diagnosing wiring issues, but I give up on this one.

Got my grubby hands on a pair of 58/15 LT (TCI) pickups (single conductor with taps) for the sig Hollowbody, installed them, and took some impedance readings that seemed right (~7.9k neck, ~8.1k bridge, ~4.0k middle). However, when I play the middle position is really weak compared to bridge or neck by itself. Only potential problem I can speculate is out of phase, but I'm not sure how that's possible with two single conductor pickups of the same brand which should be a matched set?

 

[Rider1260]

If your middle position is only 4 K you are only getting one pickup tapped not both pickups in Humbucker mode , your tapped coils should be high 3K to Low 4K

 

[Malloc]

Ok here's the actual measurement rundown. I have a 2.2k series on the bridge tap and 1.1k on neck tap per PRS specs.

Bridge: 8.05k (5.47k)
Neck: 8.04k (4.91k)
Middle: 4.06k (2.6k) - both tapped
(3.27k) - bridge tapped, neck full
(3.06) - neck tapped, bridge full

All those values check out against theoretical parallel resistance loads so I'm fairly confident it's not a short.

 

[Domingo Lantigua]

Ok here's the actual measurement rundown. I have a 2.2k series on the bridge tap and 1.1k on neck tap per PRS specs.

Bridge: 8.05k (5.47k)
Neck: 8.04k (4.91k)
Middle: 4.06k (2.6k) - both tapped
(3.27k) - bridge tapped, neck full
(3.06) - neck tapped, bridge full

All those values check out against theoretical parallel resistance loads so I'm fairly confident it's not a short.

Looks like out of phase.. reverse the wires on 1 pickup and see how it sounds

 

[Malloc]

Looks like out of phase.. reverse the wires on 1 pickup and see how it sounds

The ground on these is the shielding only so it’s gonna be *really* tricky to swap one without shorting it somewhere. I’m still puzzled at how two pickups that seemingly came from the same production guitar would be out of phase.

 

[Domingo Lantigua]

Didn't realize it was shielded wire. Sorry Someone will chime in and get sorted for you.

 

[garrett]

Ok here's the actual measurement rundown. I have a 2.2k series on the bridge tap and 1.1k on neck tap per PRS specs.

Bridge: 8.05k (5.47k)
Neck: 8.04k (4.91k)
Middle: 4.06k (2.6k) - both tapped
(3.27k) - bridge tapped, neck full
(3.06) - neck tapped, bridge full

All those values check out against theoretical parallel resistance loads so I'm fairly confident it's not a short.

Head scratcher. I agree everything seems normal.

Just throwing some ideas out to brain storm:

• This is where I'd reflow my solder joints and check my wiring just to be sure.
• If there's a cold solder joint, would it still give normal readings? I don't guess it would?
• Is the piezo active at all? The magnetic pickups could be in reverse phase from the piezo. But then, I'd think it would mess with all positions...

 

[Malloc]

Head scratcher. I agree everything seems normal.

Just throwing some ideas out to brain storm:

• This is where I'd reflow my solder joints and check my wiring just to be sure.
• If there's a cold solder joint, would it still give normal readings? I don't guess it would?
• Is the piezo active at all? The magnetic pickups could be in reverse phase from the piezo. But then, I'd think it would mess with all positions...

Problems happens on mag only and mag+piezo settings. I'll be checking everything at some point, but really don't want to take it apart again without some options to try

 

[Malloc]

Some gratuitous shots of the actual pickups:



upload image

 

[Rider1260]

I get it now , I had the same issue putting a set of Suhr Aldrich pickups in s P24

 

[Malloc]

I get it now , I had the same issue putting a set of Suhr Aldrich pickups in s P24

Any resolution?

 

[Malloc]

Update: I bypassed the piezo system and volume/tone controls - same result.

Took them completely out and tried wiring one of them backwards using the cable shield - full volume.

I guess that confirms that they're out of phase. Bummer.

 

[garrett]

Update: I bypassed the piezo system and volume/tone controls - same result.

Took them completely out and tried wiring one of them backwards using the cable shield - full volume.

I guess that confirms that they're out of phase. Bummer.

So strange. I bet they'd go great in a Singlecut, though.

 

[Malloc]

Hmmmmm a bit more Google-fu leads me to believe flipping one of the magnets should achieve the desired result.

Do I dare?

One more observation: when I put them face to face they repel only if I put the screw coils together otherwise they attract.

 

[Malloc]

I finally got a chance to go into work and use a proper soldering iron to get the case off and magnet flipped.

Hot diggity it works: no more out of phase sound! Sig SCHBII is finally gonna get the pickup swap I wanted to do months ago.