Capacitance of braided shielded wire (Gibson type), if you please? :-)

[freefrog]

Old thread but update, somehow...

I'm now sure that the capacitance of braided shielded wire is an ESSENTIAL part of the vintage wiring recipe: for obvious reasons, it hasn't much effect when a single PU is used. But when the two PU's of a LP are selected in parallel, the sound obtained really depends on the capacitive wiring. At least when vintage authentic PAF clones are used.

[wizard333]

I've noted it making a much larger difference on each individual pickup. Makes some sense since the impedance is lower in parallel, so the capacitance should affect single pickups more.

In the same way, a tone capacitor has to be roughly twice the size to have the same noticeable affect on two pups in parallel as on a single pup. For that reason, on guitars without a tone pot on each pup, I generally use a push/pull to put a larger cap in when the pickups are in parallel.

In any case, did anyone ever find some good low cap 4 conductor pickup wire? Allparts, Mojo, and Stew Mac do not list that spec and give a great big "duh" if you call and ask. I've heard there are measurable differences though from at least one pickup maker, but I don't recall which was the lower.

[freefrog]

FWIW, my last reply wasn't based on theory: it was a sum up of my personal sonic experience with several LP guitars that I've rewired with vintage braided wire.

The huge inner capacitive load due to this wiring is what appears to create that vintage hi mid "zing" when two PU's are selected. If the PU's are vintage correct PAF clones, they have still plenty of brigthness to deliver whatever is the overall capacitance of the wires and cable.

A low capacitance wiring, on the contrary, gives to such pickups a kind of sterile hi-fi flatness. IME. Their tonal response becomes broader but the vintage zing is lost.

That's why I prefer vintage correct wiring for vintage sounds, unless the pickup itself has a high inner capacitance, is prone to Eddy currents or suffers from other factors darkening the sound.

I had already posted about this finding on another forum and since my topic has been resurrected here, I jump in the train to share my experience again. My readers will do what they want with this contribution...

[wizard333]

Most LPs are wired with that stuff. The one in question I mentioned had a MUCH, MUCH higher capacitance than normal.

What you're hearing when you talk about two pickups together there is the capacitance causing, subjectively, an increase in midrange content for that position. Of course, it isn't actually doing that, but the reduction in high end content creates that aural illusion. I wire tone pots SPECIFICALLY to do that by using very small caps, I find "normal" .022uf caps completely useless, and use .0015uf to .0022uf on a neck bucker, .001uf to .0015uf on a bridge bucker; on strats .0022uf to .0047uf (this is the cap I use in parallel positions only). When you drop the tone to 0 so that very small cap is in parallel with the circuit like a very high capacitance wire, you get a perception of "fatness" and midrange increase on a strat, or on humbuckers in parallel especially. It isn't that the midrange has gone up, it's that your perception of it has gone up as it's relative makeup in the frequency range has increased as the very high end has decreased. This is especially useful on clean tones. I don't like my guitars to sound like the amp is buried in the yard somewhere, but when I roll that tone down I do want them to sound like an L5. Those small caps get that effect without losing any mix cutting capability and while keeping articulation fairly high, unlike a .022uf which kills both very quickly. With high enough cap wire, you'll get the same effect, the pickup doesn't care where the capacitance is coming from.

What you get on individual pickups of course is about the same as double what happens in parallel, and often results in too much high end articulation lost with the tone at 0, even with a very very small cap, and where distortion is used most especially. If you play slow blues lines pretty much exclusively, you might just love it. If you pick fast and rely on your rig accurately and quickly tracking the leading edge of the envelope of pick attack, you'll F'ing GD hate it. Such is the case with the high cap wire in that LP I was referring to. Sounded nice and fat and just lovely for slow stuff, but fought pick attack on fast runs like an angry gorilla.

I personally prefer a nice articulate tone; I can always add that capacitance if I want it there by rolling down the tone knobs with those small caps for a very fat clean jazz tone, but with distortion, even very mild distortion which is about all I use, it can get annoying fast if I cant get rid of it when I don't want it. Such is the case with high cap wire.

[Mike Sulzer]

Of course, it isn't actually doing that, but the reduction in high end content creates that aural illusion. I wire tone pots SPECIFICALLY to do that by using very small caps, I find "normal" .022uf caps completely useless, and use .0015uf to .0022uf on a neck bucker, .001uf to .0015uf on a bridge bucker; on strats .0022uf to .0047uf (this is the cap I use in parallel positions only). When you drop the tone to 0 so that very small cap is in parallel with the circuit like a very high capacitance wire, you get a perception of "fatness" and midrange increase on a strat, or on humbuckers in parallel especially.

Illusion? Why? You are lowering the resonant frequency, and moving the peak down into the midrange. (The pickup-capacitor is a resonant circuit.) Mr. Wizard, there is no magic here, just engineering.

[freefrog]

I often use the small cap trick myself in other contexts... A 3,3n on a push pull tone pot is useful to fatten the mids of TV Jones Classics and make them sound more like regular humbuckers. A 2,2n added on a switch in a Strat mimics the greasy tone that Hendrix or SRV were obtaining thx to high capacitance cables... Bill Lawrence (RIP) was sharing this trick a long time before any of us. :-)

In a Gibson with regular PAF replicas, it's another story IMHO.

I've wired once a LP, a SG and a Flying V entirely with expensive low capacitance Mogami. If the guitars had contained high inductance / high power / fat sounding humbuckers, this wiring would have been a good way to clean up the tone.

But with the 3 different sets of boutique PAF clones mounted in these cases, the sound was just way too hi-fi: the resonant peaks had shifted up in the spectrum in such a way that the midrange sounded flat and lifeless, with a glassy top end unpleasant under distorsion and lacking of character in clean mode.

I could have added small Styroflex caps to the Mogami wiring to warm up the sound. As the guitars weren't mine, I've found cheaper and simpler to come back to the good ol' braided shielded wire - to my ears, the capacitance due to such a wiring and to any added metallic mass gives a slightly more natural sound than an added cap.

For the record, I don't decipher the enhancement of the mids by high capacitance as being an aural illusion: yes, capacitance lowers the high frequencies. But just before the resonant peak due to the LRC filter of PU+pots+cables, it causes a "relative boost" which impacts the tone. IME.

Also: IME, two PU's in parallel with each their capacitive load adding to each other= not exactly the same sound than these PU's in parallel + a single capacitive load of the same value. I've not dug the question theoretically but I've tried a couple of times to swap between these two solutions and the result was not the same to my ears despite of the similar values read on my screen. At least when I toyed with the volume and tone controls.

YMMV: opposite experiences and opinions are what gives the pleasure to discuss and to share. :-)

[wizard333]

Illusion? Why? You are lowering the resonant frequency, and moving the peak down into the midrange. (The pickup-capacitor is a resonant circuit.) Mr. Wizard, there is no magic here, just engineering.

I missed where I said it was magic? Perhaps you should re-read.

You aren't boosting jack, it's a passive circuit. Hence my comment that the midrange "boost" is sort of an aural illusion. You're just changing which part of the frequency content becomes RELATIVELY higher or lower. Pick at that all you want if it floats your boat and makes you feel like a man I guess, or a jerk, all in the semantics.

Freefrog: I'm just not a fan of "vintage" Pafs in the bridge of anything but a strat, they are just too shrill given the neck pickup for my taste. IMO any amp setting that gets a reasonable result from a PAF in the bridge results in a festival of mud from a PAF in the neck, and any amp setting that results in usable tone from a neck PAF results in a dagger to the forehead from the bridge PAF. My personal preference is a medium output bridge pup with a very articulate neck pup like a 3k-3.5k 40ga wire pickup, or a firebird. But if you are using them, I can see where you'd want that roll off in the highs, and that is exactly what was accomplished on the LP in question, even with those low wind Gibson PAFs. Problem is, also for my playing style which involves a lot of fast picked runs, it really crapped on the front envelope of the pick attack in a way I found incredibly annoying, and in a way other LPs with that type of wire didn't do. But then those other LPs would be harsh with a PAF in the bridge.

Very occasionally I have found a passable pairing by using a low resistance volume pot on a PAF bridge, in the range of 210k-240k measured, combined with a very high resistance volume pot on a PAF neck, in the range of 900k-1100k. Even then, usually either the bridge is too bright or the neck too dark given any particular amp setting, at least to my ear. Even with a medium output bridge like a Duncan C5, I tend to want to hear a 1M pot on a neck PAF to make it tolerable given I'm not reaching over to turn the knobs on the amp when I switch pickup positions.

[Mike Sulzer]

You aren't boosting jack, it's a passive circuit.

Tell that to the man who invented the ignition circuit for your car and got 10,000 volts from a 6 volt battery. Or the engineeer who made the first audio transformer that boosted the voltage the from a low impedance microphone to improve the SNR at the grid of the first tube stage. Both, passive, both boosting voltage. The pickup/cable combination, with additional C, if used, is also a voltage boosting circuit. Series L, shunt C. Apply a sine wave at the input, sweep from low to high frequency with a constant level. The voltage out at the peak is higher than the voltage in. Otherwise, how could there be a peak? It is a low pas filter, a resonant one.

The only matter of semantics here is that you call yourself a wizard, but do not have the required sense of humor.

[freefrog]

Freefrog: I'm just not a fan of "vintage" Pafs in the bridge of anything but a strat, they are just too shrill given the neck pickup for my taste. IMO any amp setting that gets a reasonable result from a PAF in the bridge results in a festival of mud from a PAF in the neck, and any amp setting that results in usable tone from a neck PAF results in a dagger to the forehead from the bridge PAF.

Well, IME/IMHO, what you describe is the handful of flaws that I've always noticed with mainstream PAF replicas...

But it doesn't translate what I find in the very best boutique PAF clones built by a few "small" winders (who are all members here, BTW).

Their use of handguided PE coils and/or vintage correct alloys and/or custom machined keeper bars/slugs/screw poles gives a superb clarity to their PU's, along with a vintage but fast and robust attack which makes even the maddest shredding precise enough.

With such PU's, the higher capacitance of braided wire becomes a bonus, at least to my ears, while a low cap wiring pushes too high a clarity which is already there in the PU. But once again YMMV: what I say is an explanation of my subjective initatic path and not at all an argument. :-)

[wizard333]

Mike -

Conservation of energy applies. You can shift things around, with some losses overall, but you aren't boosting the energy output. Unless you've invented a perpetual motion machine? Show me your patent.

I have found over the years that inevitably in this business there are people who rely mostly on their calculations or theory, the basis and results of which they often misinterpret, and will gladly come to whatever forum, post lots of graphs and charts, and argue ad infinitum over precisely how many angels fit on the head of a pin, and insult anyone who doesn't agree with their exact calculation, and insert themselves into conversations where they contribute nothing but try to make themselves look clever to those who really don't know anything. I could give many examples.

I've also found that nearly universally, when the aural and tactile results of their work are examined, they are found sorely lacking. They'd be far better off spending more time on their bench experiencing exactly how things sound and feel, and less time on forums posting.

Freefrog: That may be so, I don't know to who's work you are referring and haven't to my knowledge experienced it. I will say that some of the Rio Grande pickups, the BBQ most especially, has high internal cap, and unfortunately to my fingers, presents the same issues as high external cap. Sounds lovely for slow passages, but fights fast picking.

[Mike Sulzer]

Wizard,

Conservation of energy always applies. So what? Not relevant. This increase in voltage in this case, as in the other two I mentioned, is accompanied by an increase in impedance, and thus a decrease in the current and so there is no violation of energy conservation. You know any ham radio operators? Ask them about transforming impedances with Ls and Cs.


Are you implying that I am an out of touch academic? Silly, there is no one who does more of all three: comparison between theory, measurement, and listening, than I do. You might try reading and thinking a bit before composing your rants. As for your criticism of academic engineering and science, it is the comparison of theory and measurement that drives everything there. Find out what is really going on before commenting.

I gave you two obvious real world examples where voltage is increased in passive circuits. You did not even comment on them, but called foul with conservation of energy. That is a joke. Unthinking criticism (in the form of irrelevant rants) of things that are obviously right is a sign of ignorance.

[wizard333]

Mikey:

I asked a question about the capacitance of available commercial 4 conductor cables.

You piped in with smart assed commentary. I don't believe "no one does more of that than you" because you don't know what your talking about. Anything connected to a car battery is not a passive circuit. Most audio transformers are powered so they don't have losses, passive ones have losses. Parallel capacitors on passive guitar circuits *DO NOT* increase voltage. They can change the frequency content or resonant frequency and hence relative voltage at specific frequencies, but they cause *LOSSES* of signal overall, not increases. I suggest you fire up a soldering iron, get a bag of caps, and get yourself some real knowledge.

You really are clueless, and I hate wasting time on the clueless and endlessly argumentative.

Freefrog had useful things to say. Our tastes may be different but at least it was a fruitful discussion. Unless you who claim to "do more of that than anyone" *snicker* have some capacitance numbers on Mojo or Allparts 4 conductor pickup wire, kindly find some other thread to hijack.

[Joe Gwinn]

Umm. Resonance there may be, but isn't necessary. Nor is conservation of energy really the issue.

Simply reducing the highs by shorting them to ground more than before will cause the midrange to increase by comparison.

The total signal energy is reduced (because of the lost highs), but the ear is fairly insensitive to amplitude variations (and one will just turn the gain up a bit anyway). The ear is however quite sensitive to the spectrum (the shape of the curve, versus its total power).

[wizard333]

EXACTLY.

Conservation of energy applies because you don't "boost" things in a passive circuit with passive components. You can trade current for voltage or the other way around, but you'll always have losses when you do that, passive or active. Nothing is 100% efficient, and definitely nothing is MORE than 100% efficient.

[Mike Sulzer]

"Anything connected to a car battery is not a passive circuit."

If that were true, than the L/C associated with a guitar pickup is not a passive circuit either. You cannot have it both ways, but in reality, the ignition coil/points of an old fashioned ignition system contains no active circuits, just as a microphone transformer is a passive circuit. For contrast, a microphone transformer could be replaced with a differential amplifier. That is an active circuit.

"Parallel capacitors on passive guitar circuits *DO NOT* increase voltage."

As I said before, it is a resonant low pass filter. This means that it passes low frequencies, attenuates high frequencies, but has a peak near the cut off frequency. The peak rises above the low frequency response (or it would not be a peak).

It is well known that a series L, shunt C can be used to alter impedance, and when you increase the impedance, you increase the voltage. Similar L/C circuits are used at rf to match antennas to amplifiers, etc, although they usually have more than two components, or they can be used to match an amplifier to a transmission line. They change impedance, and either increase or decrease the voltage depending on which way the transformation goes.

"Most audio transformers are powered so they don't have losses,"

A tranformer (primary, secondary, with core) is a passive device. They can increase or decrease voltage with a corresponding increase/decrease of impedance, and decrease/increase of current.

Transformers have losses, but they still can increase voltage. Voltage is not power; power is V^2/R or VI. Likewise a guitar pickup circuit (coil with cable or other capacitance) can be lossy but still increase voltage near the resonant frequency.

This is all very elementary electronics; you need to review the fundamentals.