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Old 01-10-2018, 06:58 PM   #11
St.Fill
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Originally Posted by Silimtao View Post
You're gonna have to hope that Fill sees this for the real technical advice.
Ha, I gotcha!!
(Thank you for that nice comment, Slim!!)

My explanations always seem to get long winded,. I know that some people here know this stuff already, but I have to assume that there are also some folks here that might NOT know, and would LIKE an explanation as to how this shit works, so here it is.
Quote:
Originally Posted by DanRode View Post
I have 2 main questions. First, assuming 500k pots, what is the difference between .047 or .022 caps, and how would the treble bleed potential change that. Imagine something like Clapton's "woman tone". Do I want the neck and bridge the same?
First up... I've been a big advocate for "less than stock" cap values for a long time. Its been my experience based on a shit-ton of trial and error that a .01uF tone capacitor works better, not only when the tone control is 'off' (wide open, on 10") but it works WAY better, and is much more useable when the tone control is rolled back off of '10'. So my first comment would be to scrap the idea of a .022uF or a .047uF cap and go .01uF or even smaller, like .007uF but not smaller than .0047uF.

THAT being said, to answer your question as you posed it, IF you want to strictly go with something that Gibby would have put in a guitar, the .022uF cap is vintage spec.
Its (very) important to understand the relationship between a tone pots value (500k, 250k, etc), and how THAT affects what gets to the cap when the tone pot is NOT being used.

Simple explanation: A potentiometer is nothing more than a variable resistor. When the pot is on '10', the pots value determines how "hard it is" (how much it RESISTS) signal getting thru it, to the cap. The CAP is nothing more than a high frequency port, ITS value determining the range of high frequencies that it will allow to pass thru it, to ground, in a passive guitar circuit.

So a 500k pot on 10 will have 500k ohms of resistance to allow ALL the pickups available frequencies to get to the cap. The cap will allow "X" amount of HIGH frequencies thru it, depending on ITS rated value. (Note: if a tone circuit did NOT have a cap in its path, the tone circuit would act as another volume pot, since nothing would be in all the frequencies way to stop them from getting to ground).

The difference between a .022uF cap and a .047uF cap is that even with a 500k tone pot, the guitar will have slightly less highs with a .047uF cap than it will with a .022uF cap. Actual Gibson vintage guitars used 500k audio taper volume pots, and 300k linear taper tone pots, FWIW. I DONT think thats absolutely necessary, but that is what was in an actual '59 LP, 335, etc.

How does all this work with the treble bleed kit? The treble bleed will counteract the effect of the tone circuits load to some degree. In all honesty, I've never done an "A/B" comparison while playing around with tone circuits to see how MUCH it will affect that, but it definitely will.

The main feature of a treble bleed, obviously, is NOT to counteract the tone circuit, but to maintain the highs that a passive circuit loses when rolling back the volume control.
I dont use them in my guitars, simply because I WANT the tone to "dull" a bit when I roll back the volume. I like that tonal change, but thats just my taste in a guitars response. Treble bleed kits work as advertised, and I would not say "DONT put one in", because what works for me might not work for someone else, and vice versa.

Quote:
Originally Posted by DanRode View Post
Next, is there somewhere I can buy matched sets of pots? CTS and Alpha are good quality but they vary. I want them as close to 500k as possible but it's more important that they test close to each other so both sets to respond the same. Otherwise, I have to buy a dozen pots, borrow a tester and hope to find some matching pairs in the group. I want to play guitar not test pots.
Quote:
Originally Posted by DanRode View Post
...OR

For $99 I can get a solderless set from Obsidian wire. All the pots are within 6% of spec and matched within 2%. Switchcraft switch and jack are also included and connect solderless. It's 3x more but the soldering is top notch and it would take me 15 minutes to install.

Lastly, are there any other ideas or options I'm missing? Different components, values or wiring?
I sincerely believe that having pots within 10% of their rated value is a perfectly fine range to be within their rated spec. (FWIW, I have never seen a 500k pot that measured 500k on the button). A 500k pot thats between 450k and 550k (10%) is totally acceptable (IMO, anyway).

I check all my pots for total resistance on a volt meter and write it in marker on the side of the pots. I just took a quick look at a few of my "500k" pots (Alpha cheapies to CTS Emersons), and they range from 413k to 495k. The audible difference between those ratings is really minimal, if even detectable at all... I dont think thats a detail worth sweating over. Pot mfg's KNOW that we sweat shit like that, and they WILL charge you for your sweat, haha!!

However, the diff between installing 500k pots and 250k pots IS audible. Thats a difference worth considering when wiring a guitar.

I feel the bottom line is that long as its a high quality pot (CTS, CTS Emerson, Bourns, etc) the guitars circuitry will be reliable, and produce the results you're looking for. I've always maintained that circuit hardware (wire, pots, caps, jacks, switches, etc) is not the place to save a buck. There is nothing worse than scrimping on something like a pot or a pickup selector switch and having to rip the guitar apart again, to replace that pot or switch cause the pot has a dead spot in its rotation, or the switch doesnt make a connection in one of its positions. IMO, thats where a volt meter with a continuity setting is worth its weight in gold. You can find shit like that before soldering it in, AND you can check for continuity as you're wiring.

Not much worse than thinking you're "done", and finding out you're NOT done, cause a solder blob is touching something it shouldnt and the guitar has a short that went undetected... till you plugged into an amp.

The pre-wired kit you mentioned DOES have some validity if you want to make your life easier, and you want that control cavity looking nice and tidy. Obviously, the other side of that coin is being able to do precision work like that yourself, which IS a learning curve in soldering, wire routing, how much of this or that wire needs to have some extra lead so that maintenance is easier, what needs shielding, *which wires would be better off with a length of shrink tubing on them... (*GIBSON BRAIDED OUTPUT JACK WIRES!!! Learned THAT one the hard way TOO many times when wiring up a semi-hollow guitar ).

ANYWAY... hope that answered your questions, Dan. If not, shoot 'em out. If I know the answer (and you dont mind reading for a while), I dont mind writing for a while.

I used to develop and facilitate training meetings when I worked, and I edit College papers now for some students, so writing is one of my passions... clearly.

Quote:
Originally Posted by DanRode View Post
If you were paying me to upgrade your guitar, would you want me to try to get it perfect or just shoot for good enough?
Exactly how I feel about helping someone with a question, assuming I know the answer to the question.
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Old 01-10-2018, 08:34 PM   #12
DanRode
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TONE CAP
======
I'm still a little confused on how a smaller tone cap would affect the tone.

Case in point, is Clapton's woman tone. I'm still experimenting with it but I roll the tone back to between 0-5. In my mind, if I went to a .1 cap, I feel I'd lose 1/2 or 1/3 of the tone control but that can't be right, can it?

What is really happening to the tone wide open, 50% and 10% when you switch to a smaller cap. I want, generally, a classic 60s LP tone. The pickups in it are doing just what they should today. So, what's the tradeoff?

SYMBIOTIC PICKUPS
=============
Today, it sounds great but, because of the "upgraded" wiring, it does some things I don't like.

In the bridge position with both volumes at 0, the guitar is silent. However if I roll the NECK volume up I can start to hear it. It never gets beyond about 10% but it's should be silent. My SG does something similar and it has coil tapping.

50s WIRING
========
I've seen the schematics of 50s style LP wiring. I can follow the diagrams and sort of understand what's going on there. The '57 classic pickups are a nod to that time as well but I like what I hear now with the modern wiring. Any value in going that way?
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Old 01-10-2018, 10:11 PM   #13
St.Fill
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Originally Posted by DanRode View Post
TONE CAP
======
I'm still a little confused on how a smaller tone cap would affect the tone.

Case in point, is Clapton's woman tone. I'm still experimenting with it but I roll the tone back to between 0-5. In my mind, if I went to a .1 cap, I feel I'd lose 1/2 or 1/3 of the tone control but that can't be right, can it?

What is really happening to the tone wide open, 50% and 10% when you switch to a smaller cap. I want, generally, a classic 60s LP tone. The pickups in it are doing just what they should today. So, what's the tradeoff?
What you have to keep in mind is that the tone cap value and the tone pot value work hand in hand with each other.
First thing to know: the signal from the pickup is constantly being fed to the tone circuit. ANY voltage signal is constantly trying to find the easiest path to ground.

Extreme examples of what feeding that signal would do with a (technically) wrong tone circuit:
If you used a 50k tone pot and a .1uF cap as the tone circuit, the guitar would sound exremely dull with almost no high end cut (or treble response) at all. The fact that the pickups signal is constantly being fed to the tone circuit and that any electrical current is constantly seeking the easiest path to ground means that the pickups signal is constantly "bumping into" the tone POTS resistance path when the pot is on "10". If there is very little resistance in the pot (50k ohms) the signal is not gonna have too much trouble leaking past that resistance. What does the signal run into when it gets thru that resistance path? The tone capacitor.
The tone cap is basically a portal which will allow frequencies thru it, starting with the highest frequencies and working toward lower frequencies dependent on the caps size (uF rating, or value). It always starts with highs and works "downwards".

A "normal" guitar circuit, with the pot on "10" (tone circuit NOT being used):
Using anything from a 250k pot to a 1meg pot (1000k ohm resistance), we have the first part of the equation... how "hard" will it be for the pickups signal to reach the tone cap? ALL of the signal WILL reach the tone cap, but we're talking about how difficult it will be for signal to reach the cap, since the pots value (resistance) is determining that difficulty.
Second part of the equation: The tone cap being basically an aperture to let high frequencies thru, will determine not ONLY how much of the high frequencies get shunted to ground when the pot is not being used, it does the same thing when the tone pot IS used. Using the tone pot simply lessens the resistance for signal to get to the cap, which is why we notice the treble loss when we roll off the tone control... its become easier for frequencies to reach the tone cap, which is grounded.
Its important to know that the tone cap IS still getting some use because even if a tone pot is 500k, some signal WILL still bleed thru that amount of resistance. Thats why those "No-Load" pots are becoming more popular. When a No-Load pot is installed, it electrically removes the tone circuit (and the treble bleed-off it presents) from the signal being sent out by the pickups. If a simple toggle switch, or a push/pull switch is used to disconnect the tone circuit, the difference as to whether its in or out IS audible.
Its something I've played with for a while, using something like a 250k tone pot that can be switched out, and a 1meg volume pot, sometimes ALSO able to switch out, leaving only the pickups, the selector switch connected to the jack. THAT makes almost a boost circuit, because almost all the signal the pickup can produce will hit the amps input now.

Quote:
Originally Posted by DanRode View Post
SYMBIOTIC PICKUPS
=============
Today, it sounds great but, because of the "upgraded" wiring, it does some things I don't like.

In the bridge position with both volumes at 0, the guitar is silent. However if I roll the NECK volume up I can start to hear it. It never gets beyond about 10% but it's should be silent. My SG does something similar and it has coil tapping.
I must say that this is something Im unfamiliar with. My LP, for example, doesnt do that. If the p/u selector is in the middle position (both p/u's on), and I roll up either p/u's volume, it will produce sound, all the way up to full volume of that pickup. Thats obviously useful in blending the two pickups tones to a certain degree.
I've never heard of a situation where the selector is set to one pickup, and you can hear the OTHER pickup if you roll up the volume of that pickup.

Quote:
Originally Posted by DanRode View Post
50s WIRING
========
I've seen the schematics of 50s style LP wiring. I can follow the diagrams and sort of understand what's going on there. The '57 classic pickups are a nod to that time as well but I like what I hear now with the modern wiring. Any value in going that way?
In '50's wiring, the tone circuit is connected to the "center" lug of the volume pot, or the "hot" lug. In modern wiring, the tone circuit is connected to the "outside" lug of the volume pot (the one thats not grounded, typically the lug the pickup is soldered to).

The deal with those two methods is in the way the circuit is presented with the tone circuits load on the circuit. In English, 50's wiring version maintains more treble response as the volume control is rolled back, but there is somewhat of a loss of volume if the tone pot is rolled back. Actually, since you mentioned it earlier, a treble bleed kit DOES smooth out that volume drop off noticeably, since up to a point, that kit re-routes treble back into the signal via the cap and resistor in a treble bleed circuit. In the case of '50's wiring, a treble bleed kit is a good thing for sure.

What is known as "modern wiring" results in a smoother transition in volume attenuation when you roll down the volume pot, but where it gives up something is in the treble response of the guitar. That wiring does lose a noticeable amount of high end when the volume is rolled off. Again, a treble bleed kit will help that.

As to which is better?? Apples and oranges. Its up to the players ears, rig and playing style, at least on the guitar they're using. One guitar might work better with '50's wiring, and another guitar may work better with modern wiring, meaning, an Ibanez shred guitar would probably work better with modern wiring, since you might WANT some treble loss with a pickup that has a lot of cut and presence. A old school kinda guitar with vintage output pickups?? I'd give it '50's wiring every time.
Personally, I do like the '50's wiring, since I seem to favor vintage specifications overall. (With the exception of tone caps. I have different ideas where caps are concerned).
Guitars I've wired with the '50's schematic have always sounded great.
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Old 01-10-2018, 11:40 PM   #14
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Thanks Fill! That really helps.

These are supposed to be school PAF pickups, so the 50s style wiring might be the way to go. I'm not sure the volume dropping a bit when I roll the down is much of an issue but it sound like a treble bleed in that case might let me have my cake and eat it too.

Need to do some more thinking before I commit to a plan of action.
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