Righteous Rotary Strat

[markd]

Righteous Rotary Strat by markd

This is a guitar mod I recently designed and performed on my MIM Fender Standard Stratocaster. (3 single coil pickups) It is inspired by the John Atchley Strat Lovers’ Strat mod but with some additional combinations and using a rotary switch. It does NOT alter the stock look of the Strat.

I’ve been very pleased with it.

What I wanted
• The five stock selections for the three single-coil pickups.
• The “missing” two parallel combinations.
• All four possible series combinations of the three single-coil pickups.
• The ability to reverse the phase of the neck pickup.

What I did NOT want
• To alter the stock appearance of my Strat.
• ANY dead switch settings.

What I was willing to give up
• One of the tone controls. (I wired the remaining tone control to be a master tone control. I prefer it this way anyway.)

The Mod - Overview
The mod consists of several parts.
• Perform the “Quieting the Beast”-type shielding, star-grounding, etc. Please see the GuitarNuts site for details. Shielding is done first. The grounding is done later in conjunction with the rest of the mods.

• Remove the neck tone pot and replace it with a four-pole five-position PRS-type rotary switch (I used StewMac item# 3512) This switch is the heart of the mod and will henceforth be referred to as S2. (S1 being the stock 5-way selector) This switch will alter the behavior of the 5-way depending on which position is selected. Stick the tone knob back on this switch.

• Rewire the remaining tone pot to be a master tone. At this point you can also change the cap to a different value according to your preference. I changed from a 0.022 uF to a 0.015 uF to make it a little less muddy and a tad brighter.

• Replace one of the remaining pots (either the master tone or the volume pot according to your preference) with a push-pull pot. The push-pull switch here will be referred to as S3 and will be used to control the neck pickup phasing.

The S2 Rotary Switch
This is a 4-pole, 5-position rotary switch. If you haven’t dealt with these rotary switches before, think of them as four 5-way switches ganged together. Your stock 5-way can be described as a 2-pole, 5-position knife-type rotary switch. (Technically, it’s a three position with intermediate make-before-break détentes.) Your stock 5-way uses one pole for the pickup selection and the other for the tone selection.

For S-2, each pole consists of a main lug which attaches to a wiper and five additional lugs corresponding to the five positions. Thus when the switch is in position #1, the wiper makes electrical contact with lug #1 and only lug #1. When in position #2 the wiper makes electrical contact with lug #2 and only lug #2, etc. When the switch is in a given position, the whole switch is in that position. The four individual switches move together as a unit.

You get the idea. If not, hold the switch in your hand and twist the knob. Observe how the wipers move across the contacts. This will quickly make it obvious how it works.

The StewMac item# 3512 rotary switch is what I used. It has a knurled shaft so you can use it with the Strat tone knob, although it was a tight fit. It looks like this:



Note: I recommend you pre-wire the S2 with all of the internal connections prior to installation into the guitar. Keep your wiring neat and minimalist as it is kind of a cramped fit anyway. You can gently bend the lugs back a bit as needed to give yourself a little more clearance.

Wiring S2
Here’s the basic idea. Please see the wiring diagram and the table below for the summary. Then read this section again.

When the rotary switch (S2) is set to position 1, we want the 5-way to behave completely normally, giving us the 5 stock settings. We do this simply by grounding the negative leads of all of the pickups.

S2, position 2 is just like position 1 except in this position the positive leads of the neck and bridge pickups are tied together. Thus when either is selected with S1, BOTH are selected. This gives us the bridge/neck combination (parallel) as well as all three pickups in parallel. This is how G&L (S-500, Comanche), for example achieves this same goal.

We now have all possible purely parallel in-phase combinations.

S2, position 3 is where we go after the most important series combinations. This works like the SW2 push-pull switch in the Strat Lovers’ Strat. We get these new combinations by lifting the negative leads of the neck and middle pickups away from ground and tying them instead to the positive bridge lead. This puts the bridge in series with whatever else is selected. (However, if the bridge itself is also selected, it causes the other pickup to be shunted out of the circuit.) This give us the bridge*neck, bridge*middle (series) combinations plus – as a by-product, the bridge in series with the neck/middle (parallel) combination.

S2, position 4, completes the remaining series combinations. We do this by stringing the three pickups together in series. We ground the negative lead of the neck, tie the positive of the neck to the negative of the middle, tie the positive of the middle to the negative of the bridge. This gives us all three pickups in series when the bridge pickup is selected on the 5-way (S1), the neck*middle series combinations in the next two settings and the neck alone in the final two.

We now have all possible purely series in-phase combinations.

S2 has one more position, but I’ve already achieved all of my objectives. Therefore, I wired this position to be identical to position 1. Here again, S1 works in the stock fashion.


The S3 Phase Switch
This allows us to reverse the phase of the neck pickup. We can do this independently of whatever pickup combination is selected. Obviously, this only makes sense to do when the neck pickup is selected in combination with at least one other pickup.

This is very simple and is exactly like the Strat Lovers’ Strat SW3 phase push-pull switch. All it does is effectively swap the positive and negative leads of the neck pickup. The wiring diagram below should make it apparent how this is wired.

Master Tone Control
Last but not least is the master tone control. This is also very simple. In the master tone configuration, the tone half of the 5-way switch is no longer needed. Simply hardwire the output of the pickup half of the S1 switch to the tone pot input terminal.
The S1 pickup output is where the S1 connects to the volume control.
The input of the tone pot is as before; it is where the S1 connected to the tone pot.
The ground side of the tone pot is also as before. One lead of the tone cap connects to the ground lug of the tone pot, the other lead of the cap connects to ground.

Now what was the stock middle tone pot is the master tone control. Now you also have tone control in the bridge position and you do NOT have two tone controls for the middle-neck position. I consider both of these to be good things.


Next are the Diagram and the Switching Table.





Conclusion

You will want to experiment with the settings and become familiar with them. This mod allows you to get a couple Tele-style sounds as well as thick humbucker-type sounds and also some weird, nasal ones. Many of these selections also have the advantage of being hum-canceling. That said, there will also be some selections that frankly aren’t all that useful. Also, keep in mind that putting pickups in series makes the sound hotter while putting the neck out of phase makes it quieter. Therefore, be prepared to adjust the volume when you switch between these types of settings.

I hope you enjoy this mod should you decide to try it out. With 19 possibilities rather than the standard 5, you could find that your old Strat suddenly has become way more versatile. Have fun with this!

markd
Apr 2007

[benjy304]

Wow, what a first post. Well thought-out and well-written. +1 for your attention to detail and explanation of your thought process. And a warm welcome to the forums ;D!

[markd]

Thanks on all counts.

markd

[JohnH]

mark - thats a major piece of design. Congrats and welcome (+1). And the good part is that you have already built it so we can assume it all works! It's also good that depite all the options, you can also chose to ignore them and use it like a normal Strat.

What did you use for volume and tone? I like to use 500k and 22nF for SSS designs with series combinations.

John

[markd]

JohnH,

Thank you.
I stuck with the 250K pots and used a .015uF tone cap.
That seems to work pretty well. I didn't try any other values, but one could certainly do that and may find better combinations.

Yes, it works. I tested all the positions once I had it put together and had corrected a couple of minor errors I had made.

Most of the ideas for this were not original; I just had to scratch my head a little to figure out how to implement it all using the rotary switch.

MarkD

[azrael]

Could a 4 pole "Superswitch" blade switch be used instead of a rotary? I assume they work the same way, looking at their construction and such.

Just curious.

[Sebster5696]

Yes you could use a Superswitch as long as you can fit the normal 5-way with the Superswitch in your cavity and on your pickguard.

Seb

[pete12345]

See the 'double barrel switching' mod on the main site. That places the new switch next to the stock 5 way, and removes a tone pot. The wiring is different but the parts are the same. The phase switch could be mounted on one of the pots or elsewhere on the pickguard if you can find the room.

Pete

[jlv]

Hey I just joined this forum because I spent the last few days inside my head trying to design a wiring mod for my strat. this post seems like its the closest to what i had in mind. would it be possible to get all the possible series and parallel combinations with a rotary switch? would I need a super switch?

here's what I had in mind

position 1-stock
position 2-N, N*M, M, M*B, B
position 3-N/B, N/M/B, (N/M)*B, (N/B)*M, (M/B)*N
position 4-N*B, N*M*B, (N*M)/B, (N*B)/M, (M*B)/N

[newey]

jlv-

Hello and Welcome!

The schematics sub-board is not really for questions about the schematics hereon, only for posting of schematics, modifications thereto, and explanations thereof.

Please don't take offense, as you can see this rule was violated regularly in the past. I'm sort of making you the guinea pig for enforcement. However, I can't move a single post, only an entire thread- and I don't want to delete your question, certainly.

There are two reasons for this:

First, we want the schematics board to be an accessible resource- if a later modification to a design is buried under 3 pages of discussion, it becomes cumbersome to find.

Second, your question is more likely to get a response if you post it in the electronics and wiring section. You can link back to the schematic for reference.

Ok, enough administrative grousing . . .

I don't have a definitive answer to your question. If you examine Markd's original table of switching options, you will notice there are several redundant positions. For example, positions 1, 4 and 5 on the rotary (S2) all yield the neck pup alone at position 1 on the 5-way switch. There are similar redundancies for the B and M pups.

There is really no way around these with a std "5-way" switch, because it's really a "3+2" switch.

You want to add all the hybrid (series/parallel combos) as well. My off-the-cuff thinking is that you'll need not only a superswitch, but one or more additional layers on that rotary to get all these.

But, again, for a definitive answer, please repost your query to the electronics and wiring section.

[ChrisK]

There is really no way around these with a std "5-way" switch, because it's really a "3+2" switch.

[/img][/quote]
It's actually a DP3T shorting lever switch (the shorting gets us the "notch" positions of N||m and M||B).


Taken in the full context of ALL possible combinations of 3 coils sans OFF and PHASE, there are 17 variants.

position 1-stock
position 2-N, N*M, M, M*B, B
position 3-N/B, N/M/B, (N/M)*B, (N/B)*M, (M/B)*N
position 4-N*B, N*M*B, (N*M)/B, (N*B)/M, (M*B)/N

The maximum switching scenario for achieving these combinations is huge. This is due to the lack of symmetry in this ordering of the combinations.

If we start with the combinations logically grouped this way;

N, M, B

N||M, N||B, M||B

N*M, N*B, M*B

(N||M)*B, (N||B)*M, (M||B)*N

(N*M)||B, (N*B)||M, (M*B)||N

N||M||B

N*M*B

we get an aneurysm.


Ok, let's regroup;

N, ---, M, ---, B

(N||M), (N||B), (M||B)

(N||M)*B, (N||B)*M, (M||B)*N


(N*M), (N*B), (M*B)

(N*M)||B, (N*B)||M, (M*B)||N


N||M||B

N*M*B

One can start to see patterns available, which should be used to reduce the complexity.


This is a complex problem, somewhat simplified by what one can "see" as one goes a'grouping.

I will be fairly surprised if this can be realized with a 4P5T lever switch and a 4P6T rotary, at least in a combination grouping that doesn't require frequent trips to the reference manual (symmetry is).


Observations;

One wire on one pickup can be permanently connected to common (ground). This leaves 5 wires to be switched (assuming three single coil pickups). If one also connects one wire of one pickup permanently to the output bus, this leaves four wires to be switched (one could short out this pickup in positions where it's not used - it'll still be "hanging around", but at least it'll be dead)).

One could use a standard DP3/5T lever switch and a 4 pole 12 position rotary switch. One position would go to the lever switch for the usual switching order. 11 positions are then available for new positions. In all, this realizes 16 of the 17 possible combinations (sans off and phase).

An advantage of this approach is that the ordering of the 11 combinations is decoupled from the wiring on the DP3/5T lever switch and can be freely illogical.

Conversely, one could use a 4P5T lever switch with one position going to the 4 pole 12 position rotary switch. In this case, any combination placement is possible. You still only get 16 combinations. "Somewhere in the middle", there may be some insight that gleans more possible states/combinations.

Good luck

[newey]

a DP3T shorting lever switch

Well, "3+2" does roll off the tongue a bit better . . .

jlv-

ChrisK is clearly trying to steer you toward the idea of decoupling the "5-way" from involvement in all the series/ parallel/hybrid combos, a valid suggestion.

You might also consider decoupling one of the three pickups, via separate switching, to help facilitate some of these combos.

And ChrisK:

I thought of moving the whole thread, but wanted to leave Markd's post where it was. Didn't mean to single out jlv. But you took the lead and fixed it, all to the good.

[ChrisK]

Hmmm, after all this is an extrapolation of markd's thread.

I'm moving it back while it's still "wiggling aboot"..

If something schematic firma comes out of this, we'll create its own "home" in "Schematics".

[azrael]

Does anyone have this diagram? I have a guitar wired up like this, and I need to some maintenance, but I don't remember how it goes. Wired it like 7 years ago hahaha.

[newey]

azrael-

Welcome Back!

Unfortunately, we suffer here from the problem of not hosting our own images. And, wherever markd's originals lie, we are no longer linked to them. Markd hasn't checked in since then, so no help from that front.

It is possible (no guarantees) that one of the other admins can resurrect those images. Give it some time, we'll see what we can do . .

[sumgai]

Sadly, my backup of everything went South as soon as I'd stuffed it all onto my file server. Never again am I going to "trust" just one disk, I now have no less than three disks containing backups in various time-frames, and enough optical media to start a retail store. It's the pits to maintain it all, but I really don't like the feeling of my pants dragging around my ankles!

A little digging showed me that markd still has a Photobucket account, but nothing pertaining to any guitar stuff remains thereon.

[azrael]

Yes, I did the same digging through internet URLs and came up with the same information. *sigh*

Thanks for looking into it, sad to hear backups were lost.

Looks like I'll have to resort to a new wiring, which is a shame, because I really liked this one.

[newey]

I have a guitar wired up like this, and I need to some maintenance, but I don't remember how it goes.

Looks like I'll have to resort to a new wiring, which is a shame, because I really liked this one.

Don't despair just yet. We just need to do a bit of "reverse engineering".

First, markd gave a detailed verbal description of his scheme. We can use that to figure out the basic plan. Second, you have the guitar already so wired. What maintenance does it need? Assuming everything is still connected, more or less, you can draw out the wiring you have, which will be (I assume) most of it.

Work calls, so I can't get to a diagram right at the moment, it may be several days. But with further input from you and with markd's notes, we should be able to figure this out.

[azrael]

Yeah, I don't think I messed with the wiring at all, but I don't remember how this Rotary switch works.

Right now, the guitar seems to sound really thin. Most of the positions don't work. I think the original rotary is pretty corroded or something.

This is the only picture I have of it now, taken right after I wired it.


I can take it apart and find out at some other time.