Post by cheecharron on Jun 20, 2017 18:48:50 GMT -5
I'm a longtime lurker (since back in the days of the great unklmickey). I finally have a question that I have not seen answered on this forum:
I'm using a DPDT on/on/on switch to wire a series/tap/parallel switch for a humbucker. I've read about the benefit of putting a resistor in the tap circuit to retain a bit of the grounded coil, thus preventing the single coil from sounding too weak on its own. However, I haven't seen anything about doing that in a series/tap/parallel switch. There's probably a good reason for that, but I am a wiring novice, so I can't be sure. That said, if I adapted a common series/tap/parallel switch by putting a resistor where the red arrows are below, could this achieve the goal of adding a bit of the south coil to the full north coil on the split? From what I can tell, the resistor wouldn't affect the series selection, as the signal could proceed unhindered through the switch-enabled connection. It also wouldn't appear to affect the parallel selection. What happens in the tap selection is a mystery to me. Any thoughts?
First off, I'm not sure a fixed resistor is going to be what you're after here, but I've never tried it so I'll let others weigh in on the merits of the idea in general. But for now, let's talk about your execution of the idea . . .
If you put a fixed resistor between the upper left lug and left center lug of your switch, you are correct that it will have no effect in the parallel setting.
However, it will also have no effect in the middle position, the coil cut (not "tap", technically, but we know what you mean) setting because it isn't connected to anything in that setting. It connects the red wire to ground, while the green wire, the other end of the South coil, is likewise connected to ground. So you won't have any output from that coil since both ends are grounded, albeit through a resistor. It is the North coil that is operative in the coil cut (or coil-split, if you will) setting.
Turning to the series setting, things get worse. Now your resistor is in between the two coils in series. This will definitely affect the tone of your HB, and probably not in a good way.
newey is correct in all but his last assertion, you don't gain anything by putting a resistor where your arrow is pointing. In the Tap position, there's no possible connection to the output for the South finish wire, so that coil won't be contributing anything to the output. However, in Series, the upper-left switch element will short the resistor, thus allowing full signal to pass through - you were right that the resistor would have no effect in this mode.
I note that this circuit is novel in that instead of shorting the undesired coil, it opens the connection entirely. By not shorting the undesired coil, we avoid any potential Dreaded Tone-Suck, conversations about which you no doubt recall from your lurking days.
With no actual diagrams to show where people are sticking this "magic resistor", I can only surmise that what they're really doing is emulating a blend control, with one fixed value. But I stand ready to be persuaded that something different is going on here, if anyone wants to enlighten me.
Last Edit: Jun 21, 2017 1:10:48 GMT -5 by sumgai: changed a smiley
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Post by ChristoMephisto on Jun 21, 2017 5:15:35 GMT -5
PRS has done it in the past with a 1k for the neck and a 2k2 resistor for the bridge. It was suppose to retain some of the beefiness of the split coil. It's worth a try, or use a cap instead if you don't like the sound with a resistor
sg is right, the series position is okay. I plead late night posting as my excuse. And, yes, a blend control allows one to "dial in" the contribution of the second coil. Your version is likely to require some experimentation to arrive at a suitable value for the resistor.
But, we're back to the basic question of whether this can be done with the on-on-on switch. I don't see how to do it, but I'm not feeling particularly clever this morning, so maybe someone else can "see" it.
Post by cheecharron on Jun 21, 2017 11:57:54 GMT -5
After going over this again and again, I see the issue with my proposed circuit. However, after trying many different alternative iterations, I can't quite seem to figure out a way to do this that doesn't alter either the series or parallel option. I'm afraid I'll have to throw in the towel on this one. However, if I manage to find a solution with a single switch, I'll be sure to post it here. Thanks for your help!