Megaswitch-E with push/pull - wiring problem

[vroooman]

Hello everybody!

I just joined after surfing the net for the best possible place for information on wiring guitar pickups... looks to me like this is it

I have a problem with the wiring on my Brian Moore C90P.13 guitar. The pickups are Seymour Duncan JB in the bridge, Alnico II Pro APS-2 in the middle and Alnico II Pro APH-1N in the neck position, switcher is Megaswitch-E model. There is only one push/pull pot and that is tone control.

Factory wiring looks like this:



but when I pull my tone pot OUT I would really like to get this instead:



And this Megaswitch is killing me. I'm not really sure if this is possible at all.

I got inside the cavity a wiring looks like this:



Can somebody help me please?

Marko

[newey]

Marko-

Hello and welcome to G-Nutz2!

In the original wiring, the Push/Pull switch is wired so as to turn the Bridge HB (both coils) "on" when you've got the 5-way switch in positions "1" or "2". Splitting the coils of both HBs is a chore handled by the 5-way switch in this wiring scheme.

(BTW, while there is no standard way to number the positions on a 5-way switch, Fender calls the neck position "5" and the bridge "1", opposite of what your diagrams show. I've been an advocate here for using the Fender designations as our "standard". But I'm using the designations as per your diagrams for clarity's sake.)

You want the P/P switch to split the HB in Position "1". This would necessarily also change position 2 as well. You would get 3 SCs at that position (with the P/P up). If that's a deal-breaker, no reason to go any further down this path.

If you don't care about the change at position 2, I think this could be done. You have an unused pole on the P/P which could be used to split the bridge pup.

I believe (emphasis on "believe", so let's await someone else to confirm this) that this could be accomplished by running a wire from terminal "6" of the Megaswitch E to the unused middle terminal of the P/P switch. Then run a wire from the unused "upper" lug of the P/P switch to ground (i.e., the one to the left as shown in the diagram, opposite where the blue wire runs to lug "3" on the Megaswitch.

[vroooman]

Newey-

Thank you for your quick reply

About switch labeling... you are right, of course. In my book, 1 was always the bridge and 5 was the neck pickup on Strats. But Brian Moore is the first guitar I bought that came with completely opposite diagrams. So in this case position 1 IS the NECK pickup and position 5 is BRIDGE... and I don't know why they did it )

Anyway, I would like to get NECK pickup -single coil only- in that position when the p/p is pulled out. Not really concerned about position 2, three singles would work just fine...

OK... we're waiting for someone else to confirm this Thanks again!

[newey]

Well, one more question. The issue here is that I don't know, without further research, the switch logic of the Megaswitch E.

Lug "6" is where the bridge HB's series junction is wired (The white and red wires together). In order to split the pickup coils, lug 6 has to be wired either to ground or to hot. Grounding the lug gets you the one coil, running to hot gets you the other.

So, when you run the new wires as I suggested, in order to get the bridge-most coil, it may be that you have to run it to hot instead of to ground.

If you don't care which coil you get, then you can just ground the P/P switch as I said initially- you'll get one or the other. If the coil matters, we'll have to delve a little deeper.

[vroooman]

When I spoke to Brian Moore support stuff about this, all I got from them was the following link:

www.stewmac.com/shop/Electronics,_pickups/Components:_Switches_and_knobs/Megaswitches/Megaswitch_E-Model.html?tab=Instructions

It explains basic things about Megaswitch, but that logic is very strange to me!

[newey]

Yes, that's all the info that's available on EYB's website or Schaller's about the switch. It's simply a table, showing you what wires connect to whcih lugs, so as to get the various available schemes (HH, HSH, etc.).

This is not the same as knowing the switch logic. To know that, we need to know what the internal connections are.

Since the website(s) don't have that info, there would be three ways to get it. First, the switch's PCB wafer is semi-translucent, so one could study the internal connections and work the switch logic out from that. This sounds to me like a major PITA.

Second, one could work backwards from the coil combinations, and figure out what lugs must be internally connected to give those coil combinations. This sort of thing makes my head spin . . .

The third, and easiest way, is to find one of the Nutz who has one of these switches, de-wired from anything, and who can apply a meter (or even just a continuity tester) between the various lugs to see which lugs are connected in the various switch positions, and who can then post us all a table for future reference (Hint, Hint!).

But, vrooman, I'm not suggesting that you do any of these things. As I said, if the particular coil doesn't matter, then (subject to someone seconding my idea), you're good to go. If the coil does matter, let me know and I'll figure it out based upon your pickup wiring.

I'm not familiar with the SD Alnico II Pro APS-2. Does this have a std. HB configuration of a screw coil paired with a slug coil? Which one do you want to be "on" when the P/P is up, the screw or the slug? Answer that, and we can work it out from there.

[vroooman]

I found this on SD Forums, although it's for Megaswitch E+, a bit different than mine:

www.seymourduncan.com/forum/showthread.php?t=239369&highlight=megaswitch

and another one that deals with similar problem:

www.seymourduncan.com/forum/showthread.php?t=241859&highlight=megaswitch

I'll post this question over there to see If they know something else...

[newey]

Vroom-

I hate to be repetitive, but if you'd answer my question about the coil, we'd get this sorted for you.

The switch logic would be nice to know, but as I said, we can figure this based upon SD wire colors and coil polarities.

The first link you have above does have a diagram of the switch logic, but I can't figure it out. It seems to be using some sort of color coding but the code isn't clear.

[vroooman]

Did you meen SD Alnico II Pro APH-1N? APS-2 is in the middle...
Yes, standard screw coil paired with a slug coil. Here is a picture of my guitar:



I would like to get the slug coil closest to the neck

[newey]

I would like to get the slug coil closest to the neck

OK, that clears it up. Your original diagram, where you circled the Moore diagram, showed the screw coil, and I also wasn't sure you had the HBs oriented in the usual way (screw coils closest to bridge and neck, respectively).

With SD pickups, the slug coil is "North", and is the black and white wires. Since the black wire is the "hot", you would ground the connection off of the P/P to get that coil. IOW, it's as I originally said- run a wire from lug #6 to the center terminal of the P/P, and ground the upper left terminal ("left" as shown on the Moore diagram).

Just to be sure you're following this, and since you have that diagram already downloaded, why don't you draw it onto that diagram, adding the two wires, and then I'll double check it (as will, hopefully, someone else.)

So far, we've had crickets from the other Nutz, but I'm around 95% confident on this . . .

[vroooman]

Ooooooooooooooh God! I made a mistake on that circled diagram It looks on it like I want BRIDGE humbucker splited I'm very sorry!

Here is the right one:



So once again, just to be totally clear Neck humbucker, slug coil CLOSEST TO THE NECK.

Very sorry for your trouble newey!

[vroooman]

And in the light of new events I should probably turn this picture 180 degrees around, so it's consistent with the first and second diagram

[vroooman]

So I did (or at list I think so ) as you said in your first post (if I understood corectly). I took a wire from lug 5 (because it is NECK pickup series junction) and soldered it to free middle terminal p/p, and I went from free upper lug to ground:



I got some pretty unexpected results!



Pretty close to what I had in mind, but I lost bridge humbucker alone and position 4 also changed (bridge HB+middle pickup)

Scratching my head...

[newey]

Vroom-

I understand you're anxious to get this done. But you rushed in to wiring it after a major change in what you wanted, before I had a chance to respond.

First of all, I said:

ground the upper left terminal ("left" as shown on the Moore diagram).

You have it to the right hand lug, which is why you've got the neck single coil with the P/P down instead of when it's up.

That's why I suggested a final diagram before you started wiring!

But, that's only part of your problem. In the original scheme, the other half of the P/P is used to turn the bridge pickup "on" when it's pulled. That wasn't an issue when we were speaking of splitting the bridge pickup, but now you've got that P/P operating on both the neck and bridge, which is why you're getting odd results.

Now we are into the question of the switch logic. We can easily disconnect the bridge pup from the P/P, and (assuming you move the ground wire for the neck, as above), you'll have the neck SC that you want when the P/P is out. But then, position 2A will be the same as position 2 (NSC + Mid).

There may be a way to keep 2A so as to include the bridge, but then we'd need to know the switch logic.

but I lost bridge humbucker alone and position 4 also changed (bridge HB+middle pickup)

This part isn't clear to me, unless you dislodged a connection while making the other changes. What coils are you getting in positions 4 and 5, both with the P/P down as well as with it up? You should use the "screwdriver tap test" to be certain which coils are "on" in the various positions.

[vroooman]

OK... I connected the P/P with neck hot wire, and used top left lug in the picture to ground it. So, after some soldering wiring looks like this:



And I got this:



This makes much more sense, because the neck HB is always in HB mode when the P/P is down and it is splited when I push the P/P up and is featured in all combinations (while P/P is up of course). Bridge HB is always in HB mode (and doesn't get splited) because it's going just through switch and not through P/P.

Interesting sound but impractical in live situation... because when I want to go from neck single coil only to bridge full HB I have to toggle the switch and push the pot.

So looks to me like both pickups have to go through P/P... Am I right?

[newey]

Bridge HB is always in HB mode (and doesn't get splited) because it's going just through switch and not through P/P.

Not true. One pole of the P/P is turning the bridge "on" when the 5-way is in positions 1 or 2, the other pole is splitting the neck SC. The bridge HB is also split by the 5-way switch in position 3.

In my last post, I suggested perhaps disconnecting the bridge from the P/P entirely, but that will then give you different results at position 2A (presumably, NSC + Mid).

So looks to me like both pickups have to go through P/P... Am I right?

.

Not necessarily, it depends on what compromises you are willing to accept and it may be possible to get closer to what you want if we knew the switch logic.

For one example, you could go back to the prior version you had, with the upper right-hand lug of the P/P wired to ground instead of the upper left; this would give you the neck SC with the P/P down at position 1. You would then also disconnect the bridge HB from the P/P entirely

Then you could flip form position 1 to position 5 to get the full HB. But, of course, there is a trade-off- you'd have to pull up on the P/P to get the neck HB.

Also note that we're back up against the problem of not knowing the switch logic. Notice that the P/P, in the original wiring, turned the bridge HB on in positions 1 and 2 of the 5-way only. It left positions 3 and 4 (where the bridge is split) alone.

But, notice that when we split the neck with the P/P, the neck SC is "on" for all positions of the 5-way switch.

Finally, note that the bridge "hot" is wired to lug "6, at the "far end" of the 5-way, while the neck "hot" is wired to lug #2, while lug #1 is left unwired.

From all this, is is apparent that the difference in the internal "logic" of the Megaswitch is an issue here. And I still can't explain why your position "4" changed when the P/P is down, that shouldn't have happened regardless of the 5-way.

It might be that moving the neck "hot" to lug 1 from lug 2 will make a difference, but no guarantees without more info on the switch.

I strenuously suggest that you put your soldering iron down while we work this out in detail, as to exactly what you want to have happen at the various switch positions. The more back-and-forth you do on your soldering, the more chances to damage something while you charge around blindly.

[vroooman]

That is probably the best option for now... I've gone back one step, to that prior version.

I played with my guitar all evening and I must say - there are some very interesting tones! Workflow suits me... I have bridge HB and neck SC in the same "layer" with PP in down position. From this point I think it will be perfect... Most of the time I would switch to neck HB for solos anyway and that was my initial idea, although PP is working "in reverse" so to speak. So after thorough examination these are existing combinations:



To my surprise, I got neck and bridge in SERIES only when they are alone. In all other instances I got them in parallel. That gave me lots of nice sounds, slightly lower in output but brighter and more SC-like. All in all I'm satisfied with this wiring for now. It's much better from what I had before.

The only thing is, I don't understand most of the things The key is definitely in understanding the Megaswitch-E logic. So if someone knows something about it, I would like to learn it!

Thanks a lot for your help newey, I put you through some hard times! I apologize for my bad drawings that made all the mess

[newey]

well, vroom, I'm happy if you like it. But there's still some oddness. . .

For starters, I still don't understand what you're getting at position 4. Per the original Moore diagram, you should have B(SC) + Mid. But your latest diagram (and the prior ones) show you getting B(HB) + Mid.

That shouldn't have changed regardless of the P/P wiring. Are you sure you're getting the full bridge HB at that position?

Also, why are some of the pickups lighter in color on your latest diagram? What does that signify?

To my surprise, I got neck and bridge in SERIES only when they are alone.

Not following you there. A HB is (ordinarily) two coils wired in series, and when you have full HB (both neck and bridge) they are, in fact, in series.

All of the combinations of two or more pickups (N + M, M + B , etc.) are in parallel.

So, as to your neck and bridge (the two HBs), you have intra-pickup series. As to all three pickups, in any/all combos with each other (B, M, N), you have inter-pickup parallel.

As to your 2 HBs, you don't have intra-pickup parallel. As to all three pickups, you don't have inter-pickup series.

(As I read back over that, it's confusing as all git-out. But there's really no way to make it any simpler ).

As far as the switch logic, again, that will require someone having a Megaswitch E which is not already wired up, and a multimeter. I may have to order one myself just to satisfy my curiosity.

[vroooman]

Yes, position 4 is definetly B(HB) + Mid... Don't know why, but I had it double and triple checked.

And those pickups lighter in colour show HBs in paralel. They have slightly less output and brighter tone... they sound more SC-like but both coils are working The sound is deffinetly NOT full HB sound or output.

In this thread I read something similar: www.seymourduncan.com/forum/showthread.php?t=249778&highlight=Series+parallel+difference

If you get to measure Megaswitch-E, I would very much like to see the results

[newey]

And those pickups lighter in colour show HBs in paralel. They have slightly less output and brighter tone... they sound more SC-like but both coils are working The sound is deffinetly NOT full HB sound or output.

I understand two coils in parallel vs being in series. But what makes you think that anything in this scheme has humbuckers wired in parallel?

There is nothing in the diagrams you posted to show any HBs wired in parallel, either in the original Brian Moore wiring, or in any of your alterations.

Both HBs are clearly wired in series. The red and white wires for each are wired together; that's the "series junction" we've been talking about. So long as red and white are connected together, you can't have parallel wiring, it's not electrically possible.

So, if you are getting lower output from your HBs where you show the lighter red coils, it's indicative of a wiring problem of some sort.

Further troubleshooting would require a multimeter. My suspicion is that your "tap testing" was faulty and that in fact, you're only getting a single coil where you show the light red. It can be difficult to tell with a HB via tapping, since tapping on an "off" coil will induce some signal in the "on" coil, although the signal will have less output than tapping onto an operating coil will have.

[ashcatlt]

A meter is far more reliable for figuring coil selections than tap test. You know...nostril...brain scan...where's that link? Course it kind of helps to measure the pickups out of circuit first, but heck! This thread seems to be all about going off half-cocked, switching horses in mid stream, and etc... ADHD is a bh!

Anyway, if it sounds good who cares what's actually happening?

[4real]

Nov 14, 2012 10:45:37 GMT -5 vroooman said:

Yes, position 4 is definetly B(HB) + Mid... Don't know why, but I had it double and triple checked.

And those pickups lighter in colour show HBs in paralel. They have slightly less output and brighter tone... they sound more SC-like but both coils are working The sound is deffinetly NOT full HB sound or output.

In this thread I read something similar: www.seymourduncan.com/forum/showthread.php?t=249778&highlight=Series+parallel+difference

If you get to measure Megaswitch-E, I would very much like to see the results

This to me actually sounds like the expected tone from this combination. The original wiring and pups of mt HSS strat sounded much the same and generally does...it's the combination of the different pups cancelling things out. The 'out of phase' sound of the #2 strat position is created not by an electrical 'out of phase' but from the physical distance between the pups along the string. The effect is to 'scoup out' the midrange. However, with an HB, the pickups are much closer together and wider and so the cancellation scoups out more and creates an excessively bright sound.

This is another reason why, in other threads, I find an HSS strat to be a compromise and a far better sound can be had by splitting the HB.

Ok...but I also wonder if the minds here could work out a way to add a cap to one of the pups in this position and moderating the cancellation and getting a much better tone in this position. It is a perenial problem with HSS gutiars in #2 and I think it is a reasonable strategy to pursue if the switch can take it. I'd anticipate a similar moderation of the HOoP mod for phasing.

The thing to remember that we are not simply 'adding' pickups but also cancelling when things are in combination...so the resulting sound is not always what one might expect intuitively.

Series combinations will often be louder and much, much darker...on my strat, this is where I really find good use for the HOoP switch to moderate that effect.

It is also a reason why I worked more on a variable 'split' and choice of split control which really made my HSS strat balanced and more versitile and more 'strat like' especially in those combinations.

Hope that helps a bit...

[newey]

Ash:

You know...nostril...brain scan...where's that link?

Funny you should mention it. I do indeed know. . .

The reason it's tough to find ChrisK's "Brain scan through a nostril" thread is that he renamed it several times.

First, it was titled "Discerning Parallel Resistances (or 'Brain Scanning through a Nostril") " Originally, it was written for a SSS guitar.

Then, he revisited the topic and supplied the math for the similar process on a HH guitar. He then split the thread into two, and renamed the first one "Discerning Strat-type resistances" and named the second part as "Discerning LP-type resistances.

Both threads are in the "References" section.

Vroom-

Ashcatlt is right, this is a much better way than tapping. This is why I was asking if you had a multimeter, if you said that you did, I was going to refer you to the above links. For a HSH guitar, the math will be a combination of the two approaches.

If you know the resistances of the various coils beforehand, the technique is a lot easier as the algebra is a lot more simple. But you have to measure the coils before they are wired into the guitar.

However, in your case, if you only need to figure out whether you've got one coil or two in operation, you can probably get close enough by using SD's factory specs for the resistances of the various pickups. Those values, as published by the manufacturer, are nominal values, your actual pickups will vary a bit from those figures. And you can't assume that both coils of a HB are exactly identical in their resistance values, but they should be close enough to allow you to see what's going on.

One piece of advice that our late mentor ChrisK gave me about working on guitars is to keep notes of each build, and to test and measure the values of all components before installation. Knowing the values makes troubleshooting that much easier, and years later, if I need to replace a component, I can easily look up what I put in there. Often, I'll work on a project for a while, and then months will go by when I don't get the time to touch it, so good notes have saved my sorry hiney on numerous occasions.