PRS McCarthy Style Series/Parallel?

[hydra]

Hi I have a PRS McCarthy style guitar which means two humbuckers, 1 volume, 1 tone push/pull pot and a three way switch. The Push/pull pot is wired to coil tap the two humbuckers into single coil. I've been pondering about how to convert this into a series/parallell system using the same hardware. Is this even possible?

This is what I'm looking for:

Tone pot Pushed (all in series)
pos 1 - Bridge
pos 2 - Bridge + Neck
pos 3 - Neck
Tone pot Pulled (preferably all in parallel)
pos 4 - Bridge Parallel (or something similar)
pos 5 - Inner coils of both humbuckers in parallel (ibanez JPM style)
pos 6 - Neck Parallel (or something similar)

Any help appreciated!

[newey]

Hi Hydra-

And welcome.

When you describe wanting "bridge series" and "Bridge parallel", and similarly on the neck pickup, I assume you are intending to retain the coil splitting feature you presently have, since "Bridge Parallel" only has meaning if you are referring to having the two internal coils of the bridge HB wired together in parallel, or alternatively, the two coils in internal series.

If that is what you want, the short answer is no, can't be done with your existing hardware. Since your push/pull is already being used to split the HB coils, it's unavailable for series/parallel switching.

As I read your list of desires here, let me rephrase what I think you want, and if I'm wrong, then the above maybe not be the case. For convenience, we'll designate the 2 coils of each HB as "N" and "S", and we'll use "+" for parallel connections of coils and "*" for series (per ChrisK's convention). So, I think you are asking for:

Push pot:
1) Bridge (N*S)
2) Bridge (N*S) * Neck (N*S)
3) Neck (N*S)

Pull pot:
1) Bridge (N+S)
2) Bridge (N) + Neck (S)
3) Neck (N+S)

If this is not what you had in mind, please expand on your wants. This is doable, but would require added switching. If you're tempted to go that route, you could also open up other options, such as HBs in internal series wired together in parallel, for example. Some of these "mix and match" parallel/series combos are considered desirable 'round these parts.

If you truly want to stick with your existing hardware, a downsizing of your desires is needed.

[ChrisK]

Well, if'n I recall, the PRS pickups that I have are three wire (yep).

This means that there is a shield, a wire within the shield, and a third unshielded wire. To select a single coil in these (and I DON"T mean coil tap, but coil short), one shorted the unshielded wire to the shield.

Now, your pickups may be four wire plus shield or one wire plus shield. If they're the former, all demented rewiring is possible, and if they're the latter, none is possible.


In semi-summary, if you have one wire plus shield on both pickups, enjoy your PRS as it is.

If you have a shield plus two wires, you can do a coil from each pickup in series, both coils within a pickup in series (that's how they're internally pre-wired), a coil from each pickup in parallel, but no internal parallel within a pickup.

If you have the four wire plus shield (essentially both ends of both coils), you can indeed do what you ask IF you have enough switching available.

newey is correct; you need two push pull pots to change each pickup (if indeed four wire) from parallel to series. You will also need a different 3-way switch known as the LP three pickup switch. I suspect that what you want can be done based on some past research in my global "No terminal Left Unconnected" program. ;D ;D

You need to report on what you have in your guitar. Different "vintages" had different stuff. We need to know how many wires and, if'n you're in possession of a digital multimeter, the resistance from all wires coming from a specific pickup to all wires on said pickup.

If you have a digital camera, a couple of well focused (or well, focused) pics would be helpful.

If you do indeed have four wire pickups, I'll revisit the GeDankengang fer a good GeThunkin'.

If you don't, do you know how to operate a band saw?

[hydra]

Thank you so much for the quick replies!

Yes you are right newey thats exactly how I picture it. I do howered like to stay low with the controls if its possible.
Been thinking more about this and it sounds like ChrisK is describing something like this;

Push pot
1) Bridge (N*S)
2) Bridge (N*S) * Neck (N*S)
3) Neck (N*S)
Pull pot
1) Bridge (N)
2) Bridge (N) + Neck (S)
3) Neck (S)

Essentially a coil tap but the middle pulled position in parallel. This would also work well for me but would it work with my setup?

Scanning around the net a little, would something like this do the trick (its the exact same hardware as mine)? www.guitartechcraig.com/techwire/tech02.jpg
I don't really know what it does as far as which coils are selected etc maybe somebody could explain it.

Both humbuckers are 4 wire + bare and nothing is soldered yet but I already got the hardware I mentioned thinking it would be enough with a single push/pull pot
I tried a Mccarthy and fell in love with the controls and wanted to make my own. Please forgive my naïve dumbness.

[newey]

HY-

Both humbuckers are 4 wire + bare

Good, we've eliminated ChrisK's concerns, and he'll give it a good "GeThunkin" because this opens up the possibilities enormously, as he noted. I kind of assumed they were 4 wire in my first reply to you, because of the coil split you described on the push/pull, the 3 wire possibility never occurred to me- but then I've never had my head under the hood of a PRS.

nothing is soldered yet

If you're starting from scratch, photos are not needed, obviously.

Essentially a coil tap but the middle pulled position in parallel.

Well, you've downsized your wants significantly. However, I think you'll still need some additional switching capability to make this happen. You're still splitting (or shunting) one coil off of each of your humbuckers, and switching the wiring between the 2 HBs from series to parallel, and I don't think you can do that with just a single push/pull pot.

I may be wrong, and I'll be summarily corrected if so. But I think you would (at least) need to change the other pot over to another push/pull to do this. Doing so would also allow you to realize Neck HB + Bridge HB, as well as Neck (S) * Bridge (N), again, assuming I'm visualizing this correctly.

Please forgive my naïve dumbness.

Well, dumbness and naivete are different topics, and I could go on a bit on that. But, in order to avoid a 3 page definitional and semantic battle, let's stick to your guitar here.

I don't know what the diagram in your link is supposed to do, either. I'm not naive, just dumb (and I don't know how to put an "umlaut" in "naive", either.)

[ChrisK]

As I'd mentioned also, you will need two push pull pots to switch two humbuckers from series to parallel. You need two poles for each pickup. Unless you have a Fender S-1 switch (4PDT), you will have to have two push pull pots. that's the bad news, but no new holes required for them. The good news is that you can have either or both in either mode.

The switching that I described was based on your original post, and not newey's.

Tone pot(ss) Pushed (all in internal series)
pos 1 - Bridge
pos 2 - Bridge + Neck
pos 3 - Neck
Tone pot(ss) Pulled (preferably all in parallel)
pos 4 - Bridge Parallel (or something similar)
pos 5 - Inner coils of both humbuckers in parallel (Ibanez JPM style)
pos 6 - Neck Parallel (or something similar)

Note that in position 2, the parallel combination of each pickup in internal series was your specification. As I've said in the past, having four coils in series gets brutally mellow. You have to decide if that's a good thing or not.

I see how to do what I reiterate above with two push pull pots (oooh, look at the long bushing unit) and an LP three pickup three-way toggle switch . Here's the technical info on the three pickup toggle

[hydra]

I still just want one push/pull on the tone as I got a special pot for the volume plus all the switching will get me confused while playing
That LP Three way toggle switch looks neat if it's indeed a on/on/on switch aswell! Further refinements and considerations gets me down to this:

Push pot
1) Bridge (N*S)
2) Bridge (N*S) + Neck (N*S)
3) Neck (N*S)
Pull pot
1) Bridge (N)
2) Bridge (N) + Neck (S)
3) Neck (S)

In my head this should be doable if I order that pickup switch and make it go parallel in the middle position (the two pickups never need to go in series with each other). The tone push/pull pot will coil tap the outer coils and combined with the middle pos should give me the fancy hum cancelling single coil sound I'm after (plus the pulled single coil 1) and 2) as a bonus).

Note I changed push pot pos 2) to go parallel since I got scared of your mellow-sound warning ChrisK it also should be easier to wire like this if I understand at least something.

Should I order away or am I thinking ahead of myself here (again)?

Btw this is the kit I got now www.rsguitarworks.net/rsstore/images/RPM_9986edit.jpg

It will take a while to get the switch as I live far far away from everything so I might as well experiment a little with what I got so I know the difference later.

[ChrisK]

It will take a while to get the switch as I live far far away from everything

Antarctica? International Space Station?

....in a galaxy far far away?


Otherwise, we do have the postal service.


BTW, this is straightforward.

Push pot
1) Bridge (N*S)
2) Bridge (N*S) + Neck (N*S)
3) Neck (N*S)
Pull pot
1) Bridge (N)
2) Bridge (N) + Neck (S)
3) Neck (S)

)? www.guitartechcraig.com/techwire/tech02.jpg
I don't really know what it does as far as which coils are selected etc maybe somebody could explain it.

This does what you want. It shorts out the coils represented by the green wires and the inter-coil tap connected to the push pull switch. On this diagram this appears to be the screw coils, with the slug coils active in the single coil mode.

It is incumbent upon you to ensure that the single coils selected are hum-canceling in the "both" position (if you care). This is what the "N" and "S" designation means.

An easy way to tell is if the row of poles from the coil of interest on each pickup magnetically stick together (string facing ends please). If they do, they are of opposite magnetic polarity and will be hum-canceling once you wire them up correctly.

You may find that this is the slug coil on one pickup and the screw coil on the other. Choose the coil that you want on the bridge pickup and use the attractive coil on the neck pickup.

Unless you have info on, or the model types of the pickups, we can't help you easily discern what correct coil wiring is.

[hydra]

Both are DiMarzios humbuckers. A D Sonic (bridge), and an Air Norton (neck). They are both currently duckttaped to the pickguard with wires facing the controls. I will check the polarity in a jiffy.

Now I see why I need that LP Switch. If Id connected both Red wires to the switch I got they would all be in series with each other(?). For middle position I need to take the Red+ one and the Black+ one to go together and the White- and Green-, right? Then in single pos the Red from Bridge or the Black from neck. (Very unsure about this)

I did mean the postal service. A week is a long long time, at least when a new guitar is sitting there waiting to be wired and set up

[ChrisK]

Now I see why I need that LP Switch. If I'd connected both Red wires to the switch I got they would all be in series with each other(?). For middle position I need to take the Red+ one and the Black+ one to go together and the White- and Green-, right? Then in single pos the Red from Bridge or the Black from neck. (Very unsure about this)

The (+) and (-) designations are orthogonally GeFooey, but rather than attempting to unwind the (+) and (-) usage, I will explain it in generic terms.


Looking here, one can discern Pickup Wire Colors and Polarity.

DiMarzio uses the following color code (please note that (AC+) and (AC-) are relative signal phase indicators and NOT DC polarity);

North magnet polarity/SLUG pole coil (usually the coil toward the other pickup)
Hot (AC+) Output RED
Not Hot (AC-) BLACK

South magnet polarity/SCREW pole coil (usually the coil away from the other pickup)
Hot (AC+) Output WHITE
Not Hot (AC-) GREEN

Shield BARE Wire


Usually, for a DiMarzio internal series structure that matches most other pickup manufacturers (consult the linked color code post) when pickups are connected in external parallel, the GREEN and BARE wires are connected to signal ground. The WHITE and BLACK wires are connected together and insulated. The RED wire is the output signal.

Since we want to have hum cancellation in the middle switch position using a single coil from each pickup, we will need to use a slug coil from one pickup and a screw coil from the other (unless we reverse the magnet in one of the pickups). Normally (more or less), the slug coils are used for single coil emulation on a side-by-side humbucker. The slug coil is similar to a slug coil single coil in sensing and the screw coil is weaker and brighter due to the thinner magnetic path thru a screw shaft (and hence adjustable).

The best thing to do is to choose the bridge coil that you like and match the neck coil to it for hum cancellation.

The screw coil normally is toward the bridge on the bridge pickup due to the richer harmonic content closer to the bridge. The screw coil on the neck is toward the neck due to it looking balanced and "cooler".

For the same signal output and phase (that AC polarity thingy), one can see the the connection order of the two coils can be reversed.

In this case, for a DiMarzio series structure, the BLACK and BARE wires are connected to signal ground. The RED and GREEN wires are connected together and insulated. The WHITE wire is the output signal. In other words, the series "stacking" of the coils is exchanged, but the individual signal phase and hence overall signal output phase is identical.

Why did we do this? Well, we can now short/shunt across the "bottom" coil on each series humbucker and effect a parallel combination of two single coils that is hum canceling.

So, in the single coil modes, the following will occur:

1. The WHITE and GREEN coil on one pickup (where the screw coil will be active)

2. That WHITE and GREEN coil on one pickup, in parallel with that RED and BLACK coil on the other pickup

3. The RED and BLACK coil on that other pickup (where the slug coil will be active)

The bridge and neck pickups will be either the one or the other.

Point is.


One pickup (screw coil active)

WHITE______Output
South
Screw (this coil is active when in single coil)
Coil
GREEN______Series tap
RED______/
North
Slug (this coil is shorted when in single coil)
Coil
BLACK______Ground
BARE_____/


Other pickup (slug coil active)

RED________Output
North
Slug (this coil is active when in single coil)
Coil
BLACK______Series tap
WHITE____/
South
Screw (this coil is shorted when in single coil)
Coil
GREEN______Ground
BARE_____/




Can you translate this to this drawing?
www.guitartechcraig.com/techwire/tech02.jpg

[hydra]

Yes! I see it! Thank you a billion times. I'll try it out on the operations table right away.

Its ridiculous how easy it all seem after it's been explained
I'll see if I can update that drawing with the templates provided at the forum for future reference.

Reporting back in a bit