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Since I use a lot of pickups, I usually just stick them on the side of the nearest fridge or file cabinet.

Here is a variation from the same era that was the precursor of the HHH design.

It does similar things, but uses master volume and tone controls.

Note that it does this with two DPDT push pull pots in lieu of one DPDT and a second LP 3-way.

Add Pickup and Modes to HH Three-way

Note that this would fit nicely within the single 3-way and two DPDT slide switch Jazzmaster paradigm.


Phasing is not addressed since that is just a sub-module between the middle pickup and the switching scheme.

This is why I posted
There are some dead combinations possible in this mod.

A chart delineating all of the possible combos might be of help. Phasing is of future worry until the 16 possible combos are known.

Comparing the actual realizations against this would be clues galore.

Yes.


It's there, you just don't see it.

The equivalent point is the north end of the isolation cap (the pickup (-) leads) on the GN drawing that you posted. Remember, your pickups are in series.

We're doing it at the volume pot since its easier (and that terminal is part of the node anyway).

So when did you have your bar-Mensa?

ashcatlt,

Your algorithm works correctly. I've run a number of seed value data sets and all are correct.

Congratulations, this was not simple.



I will as a matter of course ask you to do this.

However, operating on the premise that any (or all) of three pickups can be shorted by the switching mechanism, one only has to measure two of the single pickup positions and one of those two in series (all sharing the common volume pot) to determine the volume pot's value.

After that is known, any single pickup's DC resistance (a) is child's play after one measures it alone in parallel with the volume pot,

a = (A * V) / (V – A)

just as it was for your solution.


2, 3, 4, 5 coils, whatever.

Yes.

Sigh.

You buy them books, you send them to school, and they eat the teacher....

Fun With Toggles & Push-Pull Switches take 2 sections "B" or "D".

"B" shorts the coil hanging from hot when not selected. "D" shorts both when not selected.

This takes a SPDT for each coil.


If one doesn't want to short a coil when deselected, use Binary Tree Switching with the DPDT switches (upper right corner).

Absolutely. The volume pot is varying the resistance to the tone cap from the bias voltage from the meter. This causes an interactive balancing act. Once the volume pot stops changing, the tone cap finishes charging.


As there shouldn't be. Changing the series resistance to a capacitor in an RC circuit will have no effect if the charge on the cap is not being charged/discharged and has already settled.

The time constant of a 0.047 tone cap and a 500,000 Ohm resistor is such that the cap has reached 97% of its final value after 1 second. This is also slowed by the current output of the meter and the increasing effect of the volume pot as it's turned down.

About the only way to speed this up is to have the tone pot set to its minimum resistance.

The LP method is crucial since it gives two discrete measurements of a function using the same variables of known variation.

Without this variation, one ends up with simultaneous equations of dissimilar variables with only one measurement of each, and none with the exact same variable set.

From the other "ugly" thread;

While I'm turning the pot it reads one thing, occasionally going OL. When I stop turning it, it seems to settle toward a value, but I can never reproduce this value.

Hmmm, ya know, it seems like there may be some capacitive filtering afoot here.

Is the tone control all the way up/off so that the resistance thereof is at its largest?

Does it settle faster if it's at its full on/lower value (take the tone pot resistance out of its maximum reading settling effect)?


I started to run the algebra last night, but my SLU (symbolic logic unit) had already powered down for the night.

The maths are a bit onerous and grow quickly during expansion. Especially at 4 am. Simultaneous linear equations are middle school algebra, simultaneous non-linear ones are not so simple.

I was in no condition to fire up Maple or MathCAD (both of which contain symbolic algebra engines - no numbers required until desired), so cheating was out of the question.


I took another tack and started an iterative interpolating spreadsheet with some seed values. I started with a pickup of 5,000 Ohms and one of 10,000 Ohms, and a volume pot of 500,000 Ohms.

I calculated the measured values of the volume pot in parallel with one pickup, the other pickup, and both in series.

Using these "measured" values I used a differential ratio-metric averaging procedure that after one complete pass came up with 5,002.xxx and 10,011.xxx Ohms for the pickups and around 430,000 and 480,000 Ohms for the volume pot.

This is pretty dang close. These coil values are likely more resolute that one can read with a 3 1/2 digit multi-meter. They are certainly more accurate.

This is why I suggest the use of a multi-meter with enough digits of resolution such that one can use the same resistance range for all measurements. The different ranges are realized with scaling resistors (voltage divider) in the meter, and these are at best +/- 0.1% in accuracy. By using different ranges to gain resolution, one induces a variation of +/- 0.2% or worse in inter-range accuracy.

Using the same range will still be within the meter's absolute (in)accuracy, but at least all readings will be at the same level of ratio-metric accuracy.

If you want to get all of the digits of resolution, for most examples of paralleled pots and coils, you need a 20,000 to 40,000 count meter (4 1/2 to 4 3/4 digit). I use a 6 1/2 digit one of no small cost.


As in the above example, while I got very rapidly very close to the actual coil values, the volume pot values were low. But, so what.

As a bit of insight I tested (in math) the premise that the volume pot resistance span could be ratio-metrically applied to each pickup as a function of its ratio of the total series resistance.

For my test case pickups, I assigned 166,666 Ohms to the 5,000 Ohm coil and 333,333 Ohms to the 10,000 Ohm coil.

As suspected, the parallel values calculated were virtually identical to the "measured" values for my test cases for each pickup selected alone.


This was to be the basis for my second stage interpolation effort, but I haven't done anything with it yet since I'm already close to or better than a +/- 0.1% coil resistance error in my first interpolation stage.

I'll post my spreadsheet later. Let me know if you want me to send it to you after you see the post.

Me too.

I found that I don't need to use a cable.

Or a recorder.

It is not.

It is a box, endowed best full, of tools unobtainium, bejeweled immeasurably.

The force is such that the fasteners of what_is morph and adapt to fit.


Perception (since ever) is reality a'view.

Reality (since ever) is perception anew!


So cyn, is it built yet?

While generally pompous, annoying, and all around boring, they certainly are not idiots in the strict definition of the word (-Sigma on the intelligence curve).

Most of the folks that one meets there are like the slightly wealthy; they're slightly intelligent and go out of their way to make sure that everyone knows it.

The truly intelligent, like the truly wealthy, generally tend to not do so.


To get into Mensa one only has to be merely gifted (1 in 50). There are other high(er) IQ societies that one will never hear of.

True intelligence is self-evident.




The Mega-smart folks

just think that they're special.











Then there's them there elitists...

giga.iqsociety.org/


"......There are currently six Giga members."
giga.iqsociety.org/intro.htm


"The Giga society currently has seven members:"
giga.iqsociety.org/members.htm

(Unless, of course, one of them departs.)