Does this make any difference?

[JohnH]

Apr 4, 2016 23:34:47 GMT -5 sumgai said:

Well, John, I reverted to our "standard" assumption of all three pups having roughly equal values, particularly inductance and impedance. I know, after all the diatribe I posted above, I should know better, but for the sake of simplicity....

How will pickups contribute differently, depending on whether they are connected in series or parallel?  We've been saying for just about all of this thread that the order of the succession doesn't matter, for any given arrangement of three pickups.  Or have I mistaken your meaning here?

sumgai

My thinking is summarized in my post yesterday on page 1. But in each case, one of the three contributes a greater proportion of the total output than each of the other two. Thats even assuming they are identical PU's. And since they each sound different due to their different physical positions, so the total mix is different in each of the 3+3=6 different in-phase hybrid combos.

A good way to rationalise this is with a DC analogy and to think of each PU as a resistor, each in turn with a battery in series. Then considering the output from each seoerate battery.

[sumgai]

Well, crap, now I'm really frustrated.  Didn't we just tell shaddy that his four depicted combos would all sound the same?  I'm referring to several posts ago, namely:

Do these combinations produce the same sound? N+(MxB),N+(BxM),(MxB)+N,(BxM)+N

When several members replied "Yes", no one got upset then - what happened?

I've said all along over the years that the position of a pickup vis-a-vis the string (i.e. how far from the bridge) makes a difference harmonically, which we should consider when dealing with node cancellation, etc. Don Till's excellent java applet that shows how harmonics interact between pickups was the (indirect) forerunner of John's GuitarFreak spreadsheet, which I think now surpasses D.T.'s work.

In each of those applets, harmonic interaction can be seen, and quantified, but as has been discussed many times in the NutzHouse, over the years, the total overall volume level will remain the same, regardless of which pickup is outside of the parens (in a hybrid combo), and regardless of it being in series or parallel with the other two. I'll go so far as to agree that under a pristine listening environment, it's likely that some amount of tonal difference can be heard by some/most listeners (be they players who know what to look for, or just average peeps). However, I'll lay euros to eclairs that no one will ever distinctly vow that one combo is louder overall, than another like-wired hybrid combo. (Again, assuming near par output values for each pup.)  But when it comes to stage volumes, all bets are off - I guarantee that no one will ever be able to state with conviction that such-and-such a pickup was placed first, or wherever, in any hybrid combo the player may have engaged.

Makes me wanna go out and buy another Strat, just to wire it up all Nutzy, and record all of the various possible hybrid combos for posting - but that would be moving backwards, for me.  Anyone else wanna try it, please... be my guest.

Bottom line, for me anyways... for those who need all the possible combos for things like recording and such, fine, go for the gusto.  For those who need only a couple of a unique, non-Strat-normal tones, then the KISS principle is your friend.

HTH

sumgai

[sumgai]

Apr 5, 2016 0:43:27 GMT -5 JohnH said:

Huh?!  Did I miss something, that sentence seems to be either an incomplete thought, or perhaps a there were 3 extra letters after the word "consider".

Well, in any event, we can thank Kirchhoff's Laws for informing us that this analogy would fit my intended scenario much more closely - no matter which battery/resistor comes first in the chain, the results will be the same every time. Although I actually believe that we've gotten too simple here, for the reason that there's no "how far from the bridge" action to work on, and that's what all our hoopla is about, amiright?

As Chris might have said "Alternating current does".

 

sumgai

[col]

Hi sumgai,

For what is worth, I think we've all been confused by this thread. I think a number of us have been less than clear - I'm sure that's true of me.

My take on the three permutations being the same: that was just referring to the total impedance and resistance of the system (assuming three identical pickups). But, this does not take into account the differing signals generated by each pickup (because of their differing distances from the bridge).

As for John's analogy - when I first read that, it was late. I scratched my head and went to bed. When I looked at it again in the morning, I was still scratching my head. But, looking at it again, my impression is that John's analogy goes something like this. I'm sure John will correct me if I'm way off.

Although the pickups are identical, for the purposes of the analogy, we can assign a different resistance (in place of each pickup). This is because we will be considering a single frequency (the tonal output of each individual pickup will vary after all, even with identical pickups). When we do this, for all three permutations (for each of the two hybrid arrangements), we will end up with three different overall resistances for the three possible circuits of both hybrid arrangements. I think John's analogy was running something along those lines. I could be wrong.

[JohnH]

Ok well I feel confused as to why this seems to be confusing!

Sumgai, if all of this did indeed provoke you into getting out your soldering iron and wiring diagrams again, then that would be a wonderful outcome and worth all the posting. (Show the kids how to do it!)

In summary, and then with a diagram:

These four are all the same as each other
N + (MxB)
N + (BxM)
(MxB) + N
(BxM) + N

Because they all have N as the parallel , and more dominant PU

These three sound different to each other, because a different pickup is the main parallel one:(differences only due to position on the guitar)

B + (NxM)
M + (BxN)
N + (BxM)

Here is a diagram that breaks down how each pickup contributes, ohms law and voltage dividers result in one being dominant:



EDIT: some more explanation:
For each of pickups A, B and C, the voltage generated is divided equally across each of the three impedances Z. For pickup A the overall output is drawn from across two such impedances, so it is 2/3 Va. For B and C however, the output is only from across one Z, so it is 1/3 Vb or Vc.

So A is more dominant than B or C, and the overall sound will vary between if for example, A is in amthe bridge or the neck position.

None of this comments on whether or not these combos actually sound any good however, or whether the differences that exist are enough to want to have more than one of them. Definately simple is best. Personally, although I find it interesting to speculate on such matters, in practice I prefer the simpler sounds with just one or two coils active.

[sumgai]

Well, now we're getting somewhere.

In the main, we were (dare I say, all of us) first considering total voltage output, and disregarding tone.  Along with that however, tone was affected, and we recognized it right away, but whether the total impedance was lower or higher, thus moving the frequency peak (on the chart) upwards or downwards.

We then diverged. I was following along nicely, when it was said, about half way down Pg 1, that the three (and four) combos would sound the same. I assumed that this meant "approximate voltage output" being the same. Then somewhere more recently, that was scuttled in favor of "no, there are differences to be considered". And off on a tangent I went.

Now, with John's most recent post, I see what the problem is....

John, in your diagrams, you've arbitrarily assigned different voltage outputs to each pup, and why, I don't know. Even accounting for string position in that the Neck pup is further from the bridge, thus presumably its magnetic field is being more strongly affected by the string's wider excursion, I'm not too sure that's a realistic picture.  Remember, exactly because the string excursion is greater at this position, the Neck pup is further from the string (lower) in comparison to the remaining pups, and that will work to reduce the apparent output voltage.  But without a Strat on hand with which to test all of this, I'm now at the point where I have to admit to spouting purely theory, with no real-world proof to back it all up.

My takeaway from all of this is that pickup position in a given hybrid combo:

a) does not matter when it comes to overall output signal level;

b) does matter insofar as tone is concerned under ideal listening conditions, but not under "live performance" conditions.

and that:

1) one pup in parallel with two others in series will sound brighter (because of lower overall impedance);

2) one pup in series with two others in parallel will sound darker (due to higher overall impedance);

3) 2) will be perceived as slightly louder than 1) because that higher impedance will also increase the signal lever of the (lower) frequency peak by a perceptible difference.

HTH

sumgai

p.s. I'm getting tired, I hope that made sense!

[col]

Made sense to me!

Apr 6, 2016 23:26:47 GMT -5 sumgai said:

Well, now we're getting somewhere.
John, in your diagrams, you've arbitrarily assigned different voltage outputs to each pup, and why, I don't know.

John arbitrarily assigned values, but only for the purposes of demonstration. We are all agreed that each pickup, even if identical, will produce a different tone because of its different position relative to the bridge. That is, each pickup will have a different output (voltage) for a given frequency. So, if we consider a single frequency (with a different arbitrary output value for each pickup), it becomes obvious (and can be demonstrated by calculation) that the overall output for that frequency will depend upon which pickup occupies which position in either of the two hybrid arrangements. This difference will be true of frequencies across the spectrum; each pickup with its own frequency/output profile simply because of its relative position to the bridge. Well, that's my take on it.

My only disagreement with you (more like a difference of opinion) is that I would expect quite an appreciable difference in tone, depending which pickup is in the dominant position. John described it as dominant for a reason, and the formulas seem to support this. But, perhaps, this is just semantics. I agree: it would be nice to actually hear these differences.

[JohnH]

Ok, that's all great! Although we may not have a total meeting of minds, I think there is enough of a concensus there for me to stop being a PITA for a while.

Yes it would be nice to hear these differences. But very few guitars have these hybrid combos, and fewer still can demonstrate several of them at once, especially with three equal pickups.

I think my Strat could approximately pull off one such comparison however. I can get M + (NxB) and I can also do B + (NxM). These come from my HSS Strat, and the B in this case would be from one humbucker coil.

This bridge coil is 4.2k and 2.1H while the singles are both 6.2k and 2.4H. As set up, they have similar output levels though. Also, it is the inductance tbat is most relevant over most of the frequency range, and those values are quite close.

I'll see what happens and post a clip.

[ashcatlt]

Wasn't this thread just pretty much about which pickup was closest to ground in a series string? The answer to that is that it doesn't matter. Likewise it doesn't matter which of a paralel pair you write down first because when you wire it up their ends connect, and are not first or second but exactly the same.

Of course it makes a difference whether you've got one in series with two in parallel or one in parallel with two in series! Of course it matters which pickup is the series and which is the parallel!

My offset hybrid thing will do all of this. The pickups are all pretty different, but I could probably do a demo recording one of these days.

[sumgai]

John,

I'm sure we'd all appreciate a sampling of whatever you can record with those two combos. They may not be definitive of all the possible hybrid combos, but anything is better than nothing!

And no, no one is ever a PITA when an obtuse discussion like this arises. col's correct in that we're not all firing on the same cylinders at the same time, but then again, we are progressing along in a forward fashion. 

Also, I agree with you in that my first suppositions pointed to inductance and not impedance. Although the two are closely related, the real culprit in the ointment is actually reactance, a mathematical component in the background of our equations and formulas. It's not really necessary to go into all of that, as I am of the firm conviction that we should keep things simple here in the NutzHouse - not too many of us really want all of the engineering background, we just want answers that can be implemented without hiring Robby The Robot to do the dirty work.

---

col,

When we speak of position along the string, we are emphatically not speaking of one single frequency.  There are at least 20 demonstrable harmonics to go along with the base note, and we ignore them at our peril.  The fact that the root tone might be the strongest does not detract from the fact that many of those harmonics are contributing greatly to the overall output signal level.  Spice programs attempt to show a time-domain result of how certain component arrangements will affect the frequency response, but they don't show what's happening when two or more signals are present at the exact same time, such as when a pickup is being excited by a vibrating string.  When such programs stop sweeping from low to high, and start  showing us results of multiple same-time input frequencies, then I'll pay more attention to them.  As I remember it from my engineering days, what we really need here is something that can give us an FFT graph, in order to have real-time information.  IMHO, of course.

HTH

sumgai

[JohnH]

Apr 7, 2016 12:16:27 GMT -5 sumgai said:

John,

I'm sure we'd all appreciate a sampling of whatever you can record with those two combos. They may not be definitive of all the possible hybrid combos, but anything is better than nothing!

And no, no one is ever a PITA when an obtuse discussion like this arises. col's correct in that we're not all firing on the same cylinders at the same time, but then again, we are progressing along in a forward fashion. 

I'll do this over the weekend. I need a string change first, plus reconnect my mixer interface which got 'put away' in a recent domestic purge. I did try it briefly last night though. My wiring has a series blender which will take the more familiar N+M or N+B and transition them to (NxB)+M or (NxM)+B. The tones are different, and the effect of adding the extra pickup to the series branch provides what sounds like a small mid boost.

When we speak of position along the string, we are emphatically not speaking of one single frequency.  There are at least 20 demonstrable harmonics to go along with the base note, and we ignore them at our peril.  The fact that the root tone might be the strongest does not detract from the fact that many of those harmonics are contributing greatly to the overall output signal level.  Spice programs attempt to show a time-domain result of how certain component arrangements will affect the frequency response, but they don't show what's happening when two or more signals are present at the exact same time, such as when a pickup is being excited by a vibrating string.  When such programs stop sweeping from low to high, and start  showing us results of multiple same-time input frequencies, then I'll pay more attention to them.  As I remember it from my engineering days, what we really need here is something that can give us an FFT graph, in order to have real-time information.  IMHO, of course.

That's basically what I try to reproduce in GuitarFreak if all options are engaged. For each of up to 7 strings, 30 harmonics are calculated, based on the string tension, mass, scale length and fret position, plus the picking position and picking force. All of these harmonics are then modulated by the pickups, to give signals that take into account the pickup position, sensing width and relative output volumes. Signals from up to three pickups are then combined in proportion dependent on relative impedances, phase and whether they are in series or parallel (haven't implemented hybrid combos yet though). That signal, with a calculated combined pickup impedance, is then fed to the electrical part of the analysis to be affected by the volume and tone circuits and output wiring. The net result of all that is a snapshot of frequency response vs amplitude, somewhat equivalent to such a FFT graph. It gets complicated though, the challenge is to try to keep it KISS on the outside interface.

[ashcatlt]

Now that I think about it, maybe I don't have all of those combinations. I have a two S/P switches that are kind of "in between" the three pickups. It lets me get (N + M) x B or (B + M) x N, but I can't get (B + N) x M. Likewise, I can get (B x M) + N and (N x M) + B, but I don't think I can get (B x N) + M. So I guess that's twice as many as John's got, but leaves out the M dominant ones, which considering that I so often use the M on its own is a little funny. Oh well. I obviously haven't missed it.

Derp! Anybody paying attention could figure out that with only two toggles, I can really only get two of these combos. In this case that would be (B+M)xN and (BxM)+N.

I'm pretty sure my MiniStrat will do it with one small caveat. The "M" pickup will actually be one coil of a single-sized HB, and different combos will have to use a different one of those coils. They should be about as close to identical electronically as possible, and are pretty darn close to the same point along the string. I think it will still give us a reasonable idea of how it might go, but...

[JohnH]

Here is my clip:

hybrid combos

It starts with a strum from my three individual pickups B, M, N, then a quick taste of B+(NxM) and M+(NxB). then a longer piece of each, changing at 50sec.

[sumgai]

John,

That was interesting (and good, too!). I can hear a difference in tonality, but I'm pretty sure that the volume level stayed the same, amiright?

So what I'd been prattling about for years, way back when, I was right - pickup position does matter in determining tone, when using all three pickups. Granted, the difference is small, and on a stage in front of a crowd (with other players, to boot), such differences will likely go unnoticed. But even so, in a recording studio, one selection might be preferable over another.

I think it's fair to say that an outside pickup in a "parallel outside of series" ((A x B) + C) combo is likely to dominate, due to the pair in series being somewhat darker than the single pup that's paralleling them.  Brighter usually translates to more noticible, at least for those whose hearing is still intact.

However, I'm not so sure about a "series outside of parallel" ((A + B) x C) setup.  There, we have effectively a pair of pups in parallel, making them somewhat brighter than normal (think Tele combo here), yet that's negated by the outside pup in series with the two - every goes a little darker.  I wonder, would the parallel/brighter pair actually stand out over the single pup?  Or would it be a smorgasbord of mud?

But thanks for the clip - you can post more of them, anytime. (And the older the tune, the better!!)

sumgai

[JohnH]

Hi sumgai, thankyou for those comments. Yes the volumes are consistent between those combos, and all recording was at one level setting.

I did one build with a (A+B) x C setting, it was (B+N) x M on my sons cheapo Strat. Actually, it was the best sound that we found out of the skinny ceramic pickups. It has a nominal volume of 2x one pickup, but impedance is only x1.5 so its more powerful but not muddy. The M dominated in that case, providing 1/2 the total output, with B and N providing the remainder.