Ming shi 3L-P 3 way switch Series Wiring

[ethan]

Hello, 

Does anybody have an idea how to wire a 3 way series modification like this one: 

www.tdpri.com/threads/series-pup-wiring-on-a-3-way-switch.409343/ 

But with a Ming shi 3L-P 3 way switch?

[reTrEaD]

Hello ethan

Your tdpri link results in an error page and I have no idea what a 'Ming shi 3L-P' 3 way switch looks like, either physically or electrically.

[ethan]

The switch itself looks like most import switches, eg: 


And electronically it works like this: 

file:///Users/tacoethan73/Downloads/ming%20shi%203lp%20diagram.pdf 
I really hope the file works. 

The circuit idea is like this: 


But the switch works differently to normal telecaster switches.

[ethan]

Actually, I think this is a better diagram of the circuit: 

[reTrEaD]

Hey ethan that first circuit looks confusing but the one you displayed in your later post looks fine. We can work with that.

The pic of the switch doesn't tell much of a story. Eight lugs in a row, but other than that, who knows.

The address of the pdf file appears as though it's a file on your computer. We won't be able to access that. But you could upload that to a file host then paste the link to the uploaded file here in this thread.

If you already have an account at a file host that can accept pdf files or if you have google drive you could use that to host it. If not www.docdroid.net/ is very easy to use and you don't need to register or provide an email address. You have to do a captcha so they know you're not a bot, but that's easy enough.

If you upload with docdroid the link you'd post here will look something like this:
docdro.id/cAbBcY3
except the cAbBcY3 part will be different and unique to your upload

Once we have access to a pdf or an electrical drawing of your switch we can evaluate whether that switch will be suitable. Then we can set about the task of creating a new wiring diagram.

[newey]

Ethan:

Hello and Welcome to G-Nutz2!

RT said:

Once we have access to a pdf or an electrical drawing of your switch we can evaluate whether that switch will be suitable. Then we can set about the task of creating a new wiring diagram.

Or, if you have a multimeter (or even a simple continuity tester), you can check the switch and be sure not only of its logic, but also that it works as advertised.

Most of those import 3-way/5-way switches are laid out with the lugs as follows:

1-2-3-C C-1-2-3

But there are variations we've seen, and if yours is one of the oddballs, it'll drive you crazy before you figure out that the problem is the switch, not your wiring. So, always a good idea to check it first.

Now, as for the diagrams. The first diagram you posted (which I assume is from the dead TDPRI link) will work as advertised. The only potential issue is that the neck pickup will be "hanging from hot" when the switch is set to the bridge position. This might (or, maybe not)cause some noise. Since the prospect for some noise exists, although not guaranteed to occur, we like to avoid leaving coils hanging where possible. Here, this issue can be fixed by shorting the neck pickup to hot, using the unused lug of the "neck side" of the switch. (For discussion purposes, I'm going to call the pole of the switch that switches the neck ground wire the "neck side of the switch", and the other pole the "bridge side").

The TDPRI diagram (the guys over there are usually right . .) will work as advertised. The second diagram, by "flyswatter" will not work. Notice how, on the TDPRI diagram, there is a purple jumper wire connecting both poles of the switch at position 2. That's correct, the jumper makes your series connection at that position. However, on flyswatter's diagram, the purple jumper connects lug 2 on the neck side to lug 3 on the bridge side. This is wrong, and results in no sound at position 2. That purple jumper needs to be moved over one lug to the empty middle lug (Lug #2). Then the 2 diagrams will be identical and both will work.

[reTrEaD]

Jan 28, 2019 6:42:41 GMT -5 newey said:

However, on flyswatter's diagram, the purple jumper connects lug 2 on the neck side to lug 3 on the bridge side. This is wrong, and results in no sound at position 2.

Good catch, newey . I missed that completely.

These diagrams are built on the concepts used in the 4-way Telecaster wiring. There are a few variations on that.  Fralin's version is shown below:

Which results in:

4 - Neck
3 - Bridge and Neck in Series
2 - Bridge and Neck in Parallel
1 - Bridge

When using a 2P3T switch, it's necessary to omit one of those choice. But the omitted choice doesn't necessarily have to be Bridge and Neck in Parallel.

[axedoctor]

Jan 28, 2019 6:42:41 GMT -5 newey said:

Ethan:

Hello and Welcome to G-Nutz2!

RT said:

Once we have access to a pdf or an electrical drawing of your switch we can evaluate whether that switch will be suitable. Then we can set about the task of creating a new wiring diagram.

Or, if you have a multimeter (or even a simple continuity tester), you can check the switch and be sure not only of its logic, but also that it works as advertised.

Most of those import 3-way/5-way switches are laid out with the lugs as follows:

1-2-3-C C-1-2-3

But there are variations we've seen, and if yours is one of the oddballs, it'll drive you crazy before you figure out that the problem is the switch, not your wiring. So, always a good idea to check it first.

Now, as for the diagrams. The first diagram you posted (which I assume is from the dead TDPRI link) will work as advertised. The only potential issue is that the neck pickup will be "hanging from hot" when the switch is set to the bridge position. This might (or, maybe not)cause some noise. Since the prospect for some noise exists, although not guaranteed to occur, we like to avoid leaving coils hanging where possible. Here, this issue can be fixed by shorting the neck pickup to hot, using the unused lug of the "neck side" of the switch. (For discussion purposes, I'm going to call the pole of the switch that switches the neck ground wire the "neck side of the switch", and the other pole the "bridge side").

The TDPRI diagram (the guys over there are usually right . .) will work as advertised. The second diagram, by "flyswatter" will not work. Notice how, on the TDPRI diagram, there is a purple jumper wire connecting both poles of the switch at position 2. That's correct, the jumper makes your series connection at that position. However, on flyswatter's diagram, the purple jumper connects lug 2 on the neck side to lug 3 on the bridge side. This is wrong, and results in no sound at position 2. That purple jumper needs to be moved over one lug to the empty middle lug (Lug #2). Then the 2 diagrams will be identical and both will work.

RT - shorting the neck hot to neck return as you suggest may help some, but still leaves a fairly significant antenna connected to the signal path when the bridge only is selected - I wonder how much better it will perform

[newey]

axedoc-

It was I, not RT, who suggested that. But I take your point. However, given the desire to have the series connection at position 2, I can't see any other way to avoid the hanging coil.

[reTrEaD]

Jan 30, 2019 13:03:29 GMT -5 newey said:

axedoc-

It was I, not RT, who suggested that. But I take your point. However, given the desire to have the series connection at position 2, I can't see any other way to avoid the hanging coil.

This is an interesting puzzle, newey

If we think in terms of a 2-pole multiple position selector and the possibility of having both pickups in series and both pickups in parallel, we're stuck with having one pickup's hot wired directly to the volume control.

And personally that would be my choice. I like the Neck and Bridge in parallel so much that I'd forfeit either the Neck Only or Bridge Only to keep it.

I dislike leaving coils hanging from hot or shunting them. I'll avoid doing that when possible. But when it's necessary because of switch limitations, we do what we have to do.

---

But IF our selections are Neck Only, Both in Series, Bridge Only, then there is a way to get there without a hanging coil. We'll only have one path and never a need for parallel paths.

The first pole of the switch is wired to the volume control. Select the (+) of whichever pickup.
The (+) from each pickup is available for selection.
The (-) from one pickup is wired directly to ground.
The (-) from the other pickup is wired to the second pole of the switch.

The second pole of the switch connects the (-) of the 'other' pickup to ground or to the (+) of the first pickup, as need be.

[sumgai]

axe-y,


And both of them took their lessons from me - I was the one who started the whole discussion, way back when. ChrisK was kind enough to corroborate my position, and JohnH took pretty good-sized pains to actually perform scientifically valid experiments regarding the topic of "hanging from hot".

John's findings showed that the matter is pretty close to a non-starter. But for those who are find themselves in a different environment, one where the noise of an ungrounded, always-connected-to-hot pickup is both noticible and irritating, there is a solution, namely that mentioned above by newey.

In essence, an antenna such as you mentioned above works a bit differently than you imagine. Therein, a "hot" lead is connected to the receiver's input, and the other end goes to ground. But, the difference here is that the receiver is "tapping" a portion of the signal that the antenna is picking up. IOW, the antenna's entire signal loop consists of being excited, and discharging that energy into the ground/earth/whathaveyou. The receiver is only coupling a (rather large) portion of that energy into it's circuitry. (And yes, at that point it does act as a secondary ground path, thus introducing the possibility of a ground loop. Let's not go there just now, eh?)

In contrast, when an antenna is shorted (leads tied together), there is no stored energy to discharge somewhere else - said energy has self-cancelled. This is what happens in our present scenario with a guitar pickup. A positive-going waveform will induce a current in one direction of the coil, but when we observe each end of the coil, we will see that, in relation to each other, one end will be either negative or positive... and that's compared to the original inducing waveform. Thus, if we tie the two ends together, we'll have a cancellation effect. What remains, and what John found in his experiments, is the results of hysteresis - something is getting through to the output (the input of the amp), but it is definitely much lower in value than an unshorted coil.

And from all that, we see that there's no remaining energy of significant value to be "tapped" or coupled, like we find in a receiver circuit.  As close to noise-free as we can get with a series circuit that fairly demands a hanging-from-hot switching setup.

We can overcome any and all such difficulties, but only at the cost of greater complexity, and the resulting cost in both components and labor. For that, I'd have to say that the KISS principle is strongly advised here. I'm sure you'll agree.

HTH





sumgai

[newey]

reTrEaD- I just saw your post as I was in the process of a "back of the envelope" diagram to do exactly what you have suggested.

The first pole of the switch is wired to the volume control. Select the (+) of whichever pickup.
The (+) from each pickup is available for selection.
The (-) from one pickup is wired directly to ground.
The (-) from the other pickup is wired to the second pole of the switch.

The second pole of the switch connects the (-) of the 'other' pickup to ground or to the (+) of the first pickup, as need be.

I'll get an actual usable diagram after I'm done with work, but almost as soon as I had posted that we couldn't avoid shorting the coil, I thought of how to do it.

And, sg's point to axeMD is that it probably doesn't matter whether we short the coil or disconnect the hot anyway, but for what it's worth, I'll post the "clean" version.

[newey]

Like so:



However, we still need ethan to verify his particular switch so that I can translate the above to his switch. I don't want to "assume" it's a standard import-style switch without verification.

ethan- However, if I am right that your switch works like the standard import ones, yours will have:

1-2-3-P P-1-2-3

(Note that, when I posted earlier, I called the 2 center lugs "C", for "Common lugs", now I've renamed these as "P" for "pole", so that the terminology matches the diagram)

So, if yours operates as I suspect, translating the lug arrangement from the diagram to the switch is easy enough that you probably don't need a second diagram- just match up the lug numbers for the 2 halves of the switch. Also, you will want to be sure than you install the switch the right way around in the guitar, so that the switch points to the neck when the neck pickup is selected and vice versa. To do so, the lugs marked as #1 (which gives you the bridge pickup) will need to be closest to the neck- since the position of the switch lever is opposite of the lugs.

[sumgai]

newey,


Point taken. Nice design, does just what the customer wants.

I'm sure that throughout this discussion, I've been thinking in terms of all four possibilities available to the player.  Hence my "diatribe" above.





sumgai