One HB to the Max!

[newey]

As many know, I'm a fan of single-pickup guitars- plenty of room to strum, thump, or otherwise manipulate the strings without obstacles. And they tend to be just a wee bit lighter, too.

But unlike the legions of EVH-ish types, I demand more than just a volume knob. The idea is to see if a good palette of tones can be wrung from just one HB pickup- 4 wire, natch.

I came up with this "HB to the Max" scheme, using a 5-way Superswitch™ and a DPDT solo switch (which for some inexplicable reason I called a "load / unload" switch).

I eliminated phasing from consideration, as reversing the close coils of a single HB is unlikely to produce useable tones.

This gives each coil individually, both in parallel and in series, and in parallel through "special caps" (season to taste). I hope (and think) that it's right the first time out of the box, but given my track record . . .



Anyway, thoughts anyone? And does anyone else have ideas for a single HB scheme of an even nutzier flavor?

[JohnH]

Seems good. Another type of option that I like, particularly for a bridge position pickup, is coils in series, with one bypassed by a cap. I think I'd trade one of the two single coil options for that.

J

[lpf3]

Seems good. Another type of option that I like, particularly for a bridge position pickup, is coils in series, with one bypassed by a cap. I think I'd trade one of the two single coil options for that.

newey-I agree with John. I think both coils of the HB are picking up from almost the same area of the string & won't sound much different from one another. I learned this when I flipped a humbucker around to put the polepieces farther from the bridge, but it really wasn't much different. The series link with a cap is likely to give you a bigger difference in tone.


-lpf3

[sumgai]

newey,

Couple of points:

1) You've finally published a Version 1.0 that works! +1 for that alone. ;D

2) I'd seriously consider marking the coil names (North, South), and the polarities too. I'm of the mind that a reviewer shouldn't have to make assumptions as to what you mean when you say North, etc., nor should they have to guess at whether or not you're observing the correct polarity, and haven't "accidentally" reversed your thinking process.

3) Move the output jack to a "more normal" position of the far right of the drawing. Sticking it close by the center of the diagram makes one hunt for it.

Discussion on caps in series with a single coil:
A cap passes higher frequencies, and blocks lower ones - done deal. But an inductor does the opposite..... hence, a coil and cap combo is a bandpass (or notch) filter that tries to pass (or cancel) a limited range of frequencies, and is not "full spectrum", so to speak. I think that you'll find that your pickups no longer sound so "full", they're sort of strangled - no bottom end. If that's not the case, if they sound fine, then the cap is too large, and ineffective - you could have left it out.

John points out that a series combo with one coil shunted by a cap gives a good tone. This is because the coil and cap are in parallel, and that pairing is in series with the other coil. And that means that the bandpass filter is acting on the signal of another coil altogether, not it's own coil. Usually delivers what we've been calling a "half phase" tone.

My suggestions closely follow John's......

If you want both coils individually, use a cap in parallel with one (furthest from the bridge) to knock off some highs. For added differentiation, use a cap in series with the indvidual coil that's closer to the bridge, which should make them seem slightly lower in the frequency spectrum, and slightly higher, respectively.

Implement John's idea, probably placing the parallel cap across the "bridge-side" coil, both of those in series with the "neck-side" coil. Reverse for experimentation purposes, but I think the first way is what most players prefer. As usual, YMMV.

Next, the Nuttiness! Use a dual-gang tone pot, and use the second section to bypass (not shunt across) the cap that's in parallel across the chosen coil. Remember, it'll be like a tone pot, only two terminals will be used. However...... this might reduce the total output level somewhat. Use a low-value pot, on the order of 1KΩ or less. Even then, you still might have to consider going to an on-board buffer/pre-amp circuit, to get back to your original level. But as John is fond of saying: "A little buffering goes a long ways....". ;D

HTH



sumgai

[newey]

Thanks, guys- good points all.

lpf3-

I've made the same point about selecting either coil from a HB; whether one gets a truly distinct tone using one vs. the other I thinks depends largely on the type of HB being used. I found no difference in wiring my "Esquire-ish" guitar, but that uses a dual-rail HB-in-a-SC-size pup. A higher-output HB may well have a difference between the coils, particularly at the bridge position.

But sacrificing one SC option for a cap option is a good idea, I'll look at that in version 2.0.

SG-

Use a dual-gang tone pot, and use the second section to bypass (not shunt across) the cap that's in parallel across the chosen coil. Remember, it'll be like a tone pot, only two terminals will be used.

I'm not visualizing this at all. Do you mean that the second "gang" would only be operational when the cap is selected via the 5-way?

[sumgai]

Jul 17, 2010 6:18:16 GMT -5 newey said:

Use a dual-gang tone pot, and use the second section to bypass (not shunt across) the cap that's in parallel across the chosen coil. Remember, it'll be like a tone pot, only two terminals will be used.

I'm not visualizing this at all. Do you mean that the second "gang" would only be operational when the cap is selected via the 5-way?

Yes, that's correct - the "second section" works only when the switch selects the "cap in series with.... " option.

However, I need to modify what I said above - the pot will be used as three terminal device, not just two terminals.

1) Disconnect the cap's end that goes to the output signal line;

2) Connect the pot's outer terminals across the cap;

3) Connect the wiper to the output signal line.

Now, when the pot is rotated one way, the cap is fully in the path, but in parallel with the pot. Rotated the opposing way, the cap has almost no signal left to work with, because the signal has an easier path by going right out the short (or nearly short) across the pot's terminal-and-wiper connection.

I made this change (to my original plans) because in this lash-up, the overall volume level remains just about 100%, which in turn means no buffer is required. Only when the pot is rotated some partial amount will there be any possible reduction in volume. How much remains to be seen, by virtue of experimentation.

Which is what we Nutz are really good at, aren't we.......

HTH



sumgai

[newey]

Now, when the pot is rotated one way, the cap is fully in the path, but in parallel with the pot. Rotated the opposing way, the cap has almost no signal left to work with, because the signal has an easier path by going right out the short (or nearly short) across the pot's terminal-and-wiper connection.

OK, so we're talking about a center-detented blend or pan-type pot as opposed to a simple dual gang pot?

[sumgai]

Jul 17, 2010 20:26:45 GMT -5 newey said:

Now, when the pot is rotated one way, the cap is fully in the path, but in parallel with the pot. Rotated the opposing way, the cap has almost no signal left to work with, because the signal has an easier path by going right out the short (or nearly short) across the pot's terminal-and-wiper connection.

OK, so we're talking about a center-detented blend or pan-type pot as opposed to a simple dual gang pot?

No, we're talking about a standard dual-gang pot, no detents, no reverse or mixed tapers, no nuttin' 'ceptin' two good ol' resistance elements that happen to be varied at the same time, by the same control shaft.

You could do the job with a separate control of course, but that's another hole, and I had it in mind that you were going for simplicity here..... correct me if I'm wrong on that score.

My thought over all this was that as you are dialing the cap into the circuit, you are subtracting some small amount of bass. By turning down the Master Tone at the same time, you are cutting some treble. Those two actions combined should make for an interesting tone........ I think!



sumgai

[newey]

Well, going for simplicity insofar as there's only one pickup. But if this is to go into a Strat-style guitar, I could certainly add an extra pot. I could implement the separate trble and bass controls of Oz's "Tonemod".

Sounds like what you're after is a passive gate filter, which could indeed be interesting. A mid-scoop would also be neat, but as I think we've discussed before, there may be no good way to implement that passively.

My original idea was that 2 different cap values for the individual coils would "strangle" (Ash's term) each coil differently. However, I take your point about caps in series vs. parallel.

Or, perhaps position 1 on the switch should implement JohnH's passive diode distortion scheme- another thing I've wanted to try for some time. Problem is, I gotta go resurrect that thread for the values he used.

[JohnH]

To contribute a bit further, heres some 5Spice for your amusement:

Its based on values for a vintage PAF humbucker, divided into its two coils. Ive combined tone and volume into a single 250k pot, at max. The cord and amp input is also modelled.

First, to test this idea of a parallel combo, with a cap in series with one coil. The ‘special’ cap in question is C7



A range of values is shown, but it seems to need to be quite small, 1 or 2nf or so, to make a noticeable wiggle in the response:



Now here’s what I’m talkin’ about, coils in series with a cap in parallel with one coil. Interesting cap values are 10nF to 100nF, and I like values around that of a standard tone, cap, 20 to 50nF





Cheers

John

BTW - on the passive diode distortion - try it outside a guitar first and probably decide its not worth it!

[newey]

Well, I think that definitively answers the question!

[newey]

Here's V2.0. I labeled the n and S poles and moved the outjack per sg's suggestions. I also (hopefully) correctly implemented JohnH's suggestion at position 2, with the addition of ChrisK's "free woman" tone" style cap selection switch (but not connected to the tone control). Position 5 is both coils in parallel, each through a different cap, with the cap selection switch on the bridge coil.



I got the first diagram right first time, hopefully I'm on a roll here!

[wolf]

I agree that choosing which neck humbucker coil is cut produces very little tone change.
However, (in my humble opinion) when it is a bridge humbucker, I think there is quite a difference in tone.
To make describing this a lot easier,
COIL A - single coil that is at a further farther greater distance than
COIL B - single coil that is closer to the bridge.

Diagram

A B   B
A B   R
A B   I
A B   D
A B   G
A B   E



Selecting single coil A or B produces a LOT more treble than operating the humbucker in series.

When coil A is selected, the treble is very powerful.
However, when Coil B is selected, the treble is over the top (IMHO), and whatever low frequencies Coil A had are incredibly reduced when Coil B is chosen, along with Coil B having less volume than Coil A.

[JohnH]

On the latest diagram, the top section of the 5-way always connects to the same thing, so could be omitted. with those combos, N is always involved and so could be hard-wired to hot.

C3 always is bypassing the N coil, so a fix is needed there.

But since you have the extra switch, to select C2, C4 or no cap, you could use that to get the 'series, one-coil-bypassed-by-a-cap' sound, together with the basic series sound. That would allow a switch position to be feed up to get back the S only setting, as wolf describes. If so, that would reinstate the need for the top 5-wsy switch section.
John

[Yew]

Jul 16, 2010 22:43:23 GMT -5 newey said:

I eliminated phasing from consideration, as reversing the close coils of a single HB is unlikely to produce usable tones.

Are you sure? those tones he is getting from an OOP humbucker sound interesting, and possibly use able too..

Yew

EDIT; those tones he has at the end remind me of a ZZ top solo somewhere, i thought he was using clever muting and harmonics, god knows how he got out of phase with filtertrons though, you would have to cut them open, and those are strange pickups..

[newey]

god knows how he got out of phase with filtertrons though, you would have to cut them open, and those are strange pickups..

Filtertrons? Looks like a regular HB to me. . .

As far as phasing the HB, hey, experiment away! If the 2 coils aren't really similar it may be a usable tone, depending on one's preferences.

[Yew]

Aug 13, 2010 22:11:42 GMT -5 newey said:

Filtertrons? Looks like a regular HB to me. . .

Yeah, the video was using a regular humbucker, but the guitar used by ZZ Top is often a filtertron equipped Gretsch and to make those pickups into 4 wires would take a fair bit of work Very very strange pickups filters are..

[newey]

Not sure, but I think TV Jones makes a 4-wire Filtertron-style pup.