Four pickup wiring - with phase switch

[bbsailor]

I have a set of pickups, switches and pots from a mid sixties Italian -- probably a Galanti or Eko. There are four pickups, and they are all on a board with a circuit built in, two pickups above the circuit, two below it, so, PUs 1&@ above, 3&4 below. The switching is awesome, six positions -- all four pickups, no pickups,one, 1 by itself, 4 by itself, 1+4, or 2+3. https://link.shutterfly.com/ePOtUkVYlX

As the picks show, it looks like someone divided the leads from the pickups, wired the top two and bottom two so they could then pass through the circuit board, and then the individual pickup signals go out to the switch mechanism.

Because I don't know what the original wiring looked like, and because I have heard that lots of people thought the circuit was not very good, and because I have read that the Galanti Grand Prix 4V was meant to be played with pups out of phase . . . I am considering rewiring all this, so that I can have 1+4 in or out of phase, and 2+3 in or out of phase, and put a cap/resistor pair for treble bleed at the tone pot. I want just single tone and volume, so I can use the pickguard that I had copied from the original.

My question is -- what does this wiring look like -- should I run from the pickups to a phase switch to the pickup switch? With a simple phase switch, I could run PU 1 and PU 3 to the phase switch, so that the polarity of the signal is reversed when it hits the pickup selector switch . . . and from there is goes to tone, vol and out.

FYI -- I am in Providence, Rhode Island, USA

TIA

Ari Gabinet

If this works, I could, in theory, run both phase controlled pickups to the same, single phase switch, right? And that way I could even have all four pickups selected with the pairs in phase or out of phase. Two phase switches would give me more options . . .

I am not an expert in this area, so I am looking for help and advice. I a building a reproduction of a Galanti Grand Prix around these controls . . .

Any help much appreciated.

agabinet,

I did a modification of a G&L Telecaster-like guitar where I modified the Three Position switch (Neck, Both, Bridge, in parallel) with a Four position switch which added to the both position to the pickups being in series.

I also added stacked or concentric volume pots (500K) so each pickup could be individually adjusted even when in series or parallel. Use the volume pots as variable resistors with the pickup ground going to lug 3 of the pots. Make the pickups hot wire go to pin 2 (center) of the pots. Take the output (pin 1) from the pots to go to the selector switch. Now, make the tone pot a push pull pot with a DPDT switch where you can flip the phase of one pickup. I chose the neck pickup but disconnect any grounding to a metal case from the pickup wiring and connect it directly to the output ground after the selection switch.

What will this unique setup allow?

When two pickups are used in either series or parallel but out of phase. A slight variation of either pickup volume control (abut one tenth of a turn) will cause a variable notch effect to change the out of phase sound without needing any extra electronics. This effect is done totally passively. My guitar user of this wiring in the Atlantic City Area of NJ likes the wide diversity of this wiring and gets many comments from guitarist listeners about his unique sound.

Give it a try and let us know what you think about wiring it this way?

Joseph J. Rogowski

[agabinet]

In case anyone still is interested, I actually restored this guitar, and decided to keep the original pickup setup because it HAS an out of phase circuit built in!

[Helmholtz]

Do you know if all PUs are working? What is their resistance (DCR). Do you have a guitar to test the PUs (without any circuit connected)? Maybe just one after the other. The way they sound by themselves may help to decide for a suitable wiring.

[agabinet]

You can't measure capacitance with an ohmmeter. A good cap should show infinite resistance. As said I would assume them to be fine. Just be careful/quick when soldering. Polystyrene can't stand much temperature (70°C max.).

I took the circuit board off the plate. Here are pics. It's clear that there are three cap/resistor circuits. The one with the 2200 pf cap is the "mute" setting . . . https://link.shutterfly.com/Wv25r0IKsX

[Helmholtz]

But I don't get any movement of the needle of my meter when I test them. I set the ohm meter at 10K . . . and get no movement.

You can't measure capacitance with an ohmmeter. A good cap should show infinite resistance. As said I would assume them to be fine. Just be careful/quick when soldering. Polystyrene can't stand much temperature (70°C max.).

[agabinet]

Surely not 1600µF or 2200µF caps. Those would be useless in guitar. I suppose they are 1600p(pico)F and 2200pF (pictures of the markings would help) and I doubt that they are defective. The 3 caps in your pictures look like good quality "Styroflex" (polystyrene) caps.

You are correct, shows you how little knowledge I have. The caps say "1600 pF/5% 250V" and "2200 pF/5% 125V"

But I don't get any movement of the needle of my meter when I test them. I set the ohm meter at 10K . . . and get no movement.

[Helmholtz]

two fairly straightforward cap/resistor in parallel filters, one for 1 & 2 and one for 3& 4 -- both with 1600 mu cap and a resistor whose value is . . . yet to be determined.

One cap/resistor pair with a different value -- 2200 mu cap and a different resistor --

Surely not 1600µF or 2200µF caps. Those would be useless in guitar. I suppose they are 1600p(pico)F and 2200pF (pictures of the markings would help) and I doubt that they are defective. The 3 caps in your pictures look like good quality "Styroflex" (polystyrene) caps.

[agabinet]

Multimeter very helpful today --

First, I think all the caps are dead.

Second, I think the circuit board has three circuits in it

two fairly straightforward cap/resistor in parallel filters, one for 1 & 2 and one for 3& 4 -- both with 1600 mu cap and a resistor whose value is . . . yet to be determined.

One cap/resistor pair with a different value -- 2200 mu cap and a different resistor --

This latter cap/resistor pair leads to the "0" switch -- which, I believe, is a mute, but not a silencer, but just a more muffled tone . . .

So now I think I have to remove the circuit board from the metal plate (it's riveted) and replace the caps.

[agabinet]

https://link.shutterfly.com/wQTX8l1NpX

The six way switch works, there is a selector button for "0" -- no sound, But this selection actually creates a contact with a lead coming from the circuit board. This leads me to conclude that the circuit board has a muting function built in? There are six possible selections from the switch, and four leads coming from the circuit to the switch, only one lead coming out of the switch. The available selections are:

All
1 (switch creates a contact between the output lug and one input lug)
4 (switch creates a contact between the output lug and a different input lug)
1+4 (Switch creates contact between output lug and the 1 input and the 4 input lugs)
2+3 (switch creates contact between output lug and yet another input lug)
Mute (Switch creates contact between output lug and the fourth input lug)

The four leads coming out of the circuit and connecting to the input lugs in the switch, therefore, must be

1
4
2+3
Mute

There is a bunch of wire splicing from the pickups -- essentially wiring 1+2 together and wiring 3+4 together. It is NOT factory original. This leads me to conclude that someone tried to pair the pickups to make a sort of "humbucker by proxy" set up. All I really need to do to get back to original is figure out how to wire the inputs from the pickups. It should actually be pretty easy because there are matching colored wires on the switch input lugs and the circuit outputs . . .

[agabinet]

You could run test leads out and try all of this outside the guitar before you commit to anything.

With 6 switches you could wire each pup to a switch and have 2 left for phase switching.

I don't know how important the original board is to you.

👍 Got the multimeter out.

[ric]

You could run test leads out and try all of this outside the guitar before you commit to anything.

With 6 switches you could wire each pup to a switch and have 2 left for phase switching.

I don't know how important the original board is to you.

[big_teee]

I think the phase switching will work.
Don't have a clue how the 1&4, 2&3 magic works.
I think you will have to do a lot of trial and error wiring, and testing.
When I wire something exotic, I do lots of simulating, switching, checking continuity with a ohm meter, for the load, in place of the pickups.
Give it a try, and please keep us posted with your outcome!
Then

[agabinet]

We really need a layout, or schematic of your pickups, & switches, before I could confirm anything.
Can you draw it out on paper and submit it here?
T

https://link.shutterfly.com/W8fnlQqcoX

Sorry I can't seem to upload the pics directly. I'm pretty much a beginner with wiring.

[big_teee]

We really need a layout, or schematic of your pickups, & switches, before I could confirm anything.
Can you draw it out on paper and submit it here?
T

[agabinet]

I was also thinking of the Brian May guitar wiring.
Each of the 3 pickups have an on off, and each pickup has its own reverse polarity.
You can get any combo, you could do that with a 4 pickup, by using eight switches.
T
[ATTACH=CONFIG]53902[/ATTACH]

Love that brian may setup. But I already have SIX selector switches! and since only one PUP out of each paid needs to be out of phase, I could do Phase switches for 1 & 3 and I would have all my combinations available through the selector (1/4 and 2/3) covered. I just want to confirm that the pickup signal should go first to the phase switch, then to the selector switch . . .