Phase switch woes

[pedalhead2]

Hey all,

First post and am looking for some guidance.

I have been tinkering with my Epiphone 3 pickup SG Custom for a bit. Wanted to simplify down to a master volume and tone (I enjoy the simplicity of my tele). With the other holes in the body I put on/on mini toggles. One for switching the middle pickup on and off. The other is the switch the phase on the bridge pickup. As of this moment the neck and middle pickup sound glorious but the bridge can only be heard at a minimal volume at 9 and above on the volume pot. No hums or crackles. Tap the solder joint with change. Height of pickup is the same as before when it had independent volumes. The mini toggle has been used before and worked well.

Could this be a grounding problem?
Does a phase switch drop the volume because of loss in the switch?

Any help would be appreciated.

[reTrEaD]

Jun 22, 2021 14:00:22 GMT -5 pedalhead2 said:

Does a phase switch drop the volume because of loss in the switch?

No. There aren't any appreciable losses in a switch to cause a loss in volume. Whether in-phase or out-of-phase, the pickup will sound the same when selected by itself, as it would without a phase-switch in the circuit. When combined with another pickup, in-phase will sound the same as if there wasn't a phase-switch in the circuit. Out-of-phase combined with another pickup will sound radically different. And there's generally a significant loss in overall volume.

Worth noting: Gibson (and Epiphone) often cable their HBs with a single inner conductor plus a braided shield. Attempting to add a phase switch to a HB that's cabled that way will only lead to grief and tears before bedtime.

[newey]

Jun 22, 2021 14:00:22 GMT -5 pedalhead2 said:

The other is the switch the phase on the bridge pickup.

First off, I assume 3 humbuckers here, since I've never seen a 3-pickup SG with P90s. When you say "phase switch on the bridge pickup", is this putting the bridge pickup out-of-phase with the middle and neck pickups? Or is it putting the 2 coils of the bridge HB out-of-phase with each other?

If it's the second one, that would explain your issue. Out-of-phase between the coils of a HB doesn't work very well because the two coils are so close together.

If it's the first of the 2, we wouldn't expect a huge reduction in volume to the extent you describe. Some reduction is typical but not that much. Can you draw a diagram of how you have this wired at present?

Also wondering about the 3-way pickup selector. The 3-pickup Gibson/Epiphone guitars typically had a specialized 3-way switch that just allows for each of the three pickups to be selected individually. You indicated that you had rewired the middle pickup to have a separate on/off mini-toggle, so I'm wondering what you did with the 3-way switch. How is that wired now- and what happens (or is supposed to happen) in the middle position?

Edit: Oh, and I forgot my manners!

Hello and Welcome to G-Nutz2!

ReTrEaD and I posted over the top of one another, but he raises a point of which I also should have thought. Not just the braided shield cable, but if the pickup covers are also grounded that could explain (potentially) your issues.

[pedalhead2]

Thanks to both of you for the reponses.

Retread: I have 4 conductor Seymour Duncan’s in all positions (Jazz, Seth Lover, and 59/Custom Hybrid). So I hope I don’t have the Epiphone HB conductor issue.

Newey: adding a drawing will take some learning for me and I will try that later. Essentially it is wired like this:
Neck hot wire goes the 3 way switch first then vol pot.
Middle hot wire to a mini toggle then vol pot
Both of these pickups are have the green/bare wire to ground.
Bridge hot wire and green/bare wires go to opposite sides of the middle lugs of a mini toggle. Both outer lugs are crisscross connected and output is run off one set of lugs. (Confusing but I took it from a premier guitar schematic). One output lug goes to ground and the other goes to the 3-way switch.
3-way switch goes to the vol pot.
The 3way, bridge, pots, and jack are grounded.
The out of phase within the pickup is something that I never considered. I will have to check to make sure I didn’t have to separate the green and bare wires in the set up.

As I said before… Thanks. Definitely gives me some direction to go in with researching this issue.

[newey]

OK, no need for a diagram, the description answers my questions.

I have 4 conductor Seymour Duncan’s in all positions

OK, no issue there in that case. Since you didn't mention any coil-splitting, I assume the Red/white wire pair are wired together. Wrap this connection with some electrical tape if you have not already done so.

Bridge hot wire and green/bare wires go to opposite sides of the middle lugs of a mini toggle.

This is a potential clue. The bare wire is a shield ground. It is not carrying signal and is thus always grounded (typically, to the back of one of the pots, or to a star-grounding point). Whether this is the cause of the problem or not, I dunno, but it could well be. Disconnect that wire from the switch and wire it straight to ground. The green wire stays put.

From your description, it sounds like you do not have the N + B combo available? The mini-toggle either adds the middle or not, but there is no center N + B setting on the 3-way?

The out of phase within the pickup is something that I never considered. I will have to check to make sure I didn’t have to separate the green and bare wires in the set up.

No worries. From your description, you have not done so (red/white pair would be going to the phase switch if that were the case).

[pedalhead2]

Newey, I think you are spot-on with the green/bare combo. After your earlier post, I looked at a Seymour Duncan specific diagram for phase split. The green and bare are separated on that diagram. I was using and telecaster bridge diagram.

The pickup options should be for this guitar:
N, N&B, B, NM, NMB, MB and N&B out of phase, NMB out of phase, MB out of phase.

Thanks so much.

[newey]

OK, from your description I couldn't tell if you had rewired the 3-way switch or not. Let us know if moving the bare wire does the trick.

[pedalhead2]

Bare wire grounded
3 way switch resoldered
And now it works.
Tons of great tone at hand and all are quickly accessible
Interesting that the out of phase tones for the middle/bridge combo is more quacky than the neck/bridge combo. I thought the wider the spread of the pickups the more out of phase it would sound. Maybe it is the differences in the pickups.

Thanks!

[newey]

Jun 22, 2021 21:16:40 GMT -5 pedalhead2 said:

I thought the wider the spread of the pickups the more out of phase it would sound. Maybe it is the differences in the pickups.

The wider the spread, the less cancellation of frequencies. Not "more out of phase", but a more useable OOP sound. Neck OOP with bridge will have less volume drop, and sound less "phase-ey" That's why I mentioned the two coils of a HB being OOP- this doesn't work well because the coils are so close, virtually all the frequencies are common, and cancel each other out, leaving a very thin, low output signal.

Similarly, many folks find that a series OOP sound is more useable than a parallel OOP like you have done.

The type of pickup definitely makes a difference, too, but your results are as expected.

[pedalhead2]

Thanks, Newey!

Great info. Now that it is working… time to play.