Capacitors - What is the historic vintage cap VALUE for archtops?

[tjmicsak]

Whenever the question comes up on Cap values the conversation always seems to drift to cap type instead of the traditional VLAUE used in vintage archtops, which is fine in regards to vintage Les Pauls, Centralabs Pots, Tapers yadda yadda yadda. .

For the sake of cutting to the chase, this is not regarding Les Pauls and the continual PIO, pot taper, Cap TYPE and so on.

What I am looking for is the historically accurate capacitor VALUE used in the old archtops like the ES-175, L5ces, and 335s-
assuming floating or mounted humbucker and 500K quality Pots.

Were they .022, .033, or .047?
Were both pickups the same values?

I have seen many a wiring diagram for the Varitone circuits but have never found any actual diagrams or schematics for vintage archtops.

[ThatRhythmMan]

This is the .022 capacitor in a 1963 harness. I can check some others.


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[tjmicsak]

Reason for asking is that I am upgrading an Epiphone Joe Pass with Duncan Seth Lover Pups, CTS Pots, and PIO caps. The old stuff coming out that Epiphone chose to put in includes typical low cost Green Chiclet Poly caps, as a given, but the values are both .047. I'm curious why Epiphone, a subsidy of Gibson, would choose to use that cap value for a guitar that at the same time had Joes name associated with it, wondering if Joe actually had used a higher value cap.

While we all focus on style, skills, and knowledge of the music and artists, I often wonder what, if any tone mods any one of the great Jazz players may have done or had done.

Just a curiosity why .047s are in a "signature" model, and that would determine what value I use for a better quality cap value selection for the upgrades I am currently doing.

Another interesting discovery is that the Epiphone Joe Pass is NOT 50s wiring, it is a variation on "modern" wiring, AND the pickup leads are wired to the volume pot wiper (center) so that each pickup can be fully rolled down in the middle position without grounding the other pickup out, keeping them each independent and live even if the other volume is at zero (grounded). This is not typical for Gibson/Epiphone so the uniqueness of the wiring and the pot values begs the question of if they did this on purpose possibly copying in kind with either artist mods or preference.

[sgosnell]

Caps are caps, as long as they are within tolerance, and they all have a tolerance, usually 10% or so. The value is chosen to give the desired sound. .047 caps are generally used to tame brightness, to roll off more highs when maxed out, and are the highest value normally seen in guitars. When the pot is fully off, the capacitor does nothing. There is no single value used in vintage archtops, they vary as do modern ones. It's cheap and relatively easy to replace the capacitors, to see which one prefers. There is no magic in big capacitors, the smaller ones work just as well. Older caps were bigger because the manufacturing technology didn't permit smaller. Everything is smaller now, and that's generally a good thing.

[Cunamara]

Well, Joe's ES 175 was a 1964, so whatever values Gibson was using for their patent number pickups around then would be what he used. Probably exactly the same as all their other humbucker guitars, such as the Les Paul. My guess is 500K potentiometers and a .022 mf capacitor.

And not to get into it too much, but in this application the only thing that matters is the capacitor value. The signal going through the capacitor goes to ground and you never hear it. It might be a different story in an amp with a bright cap, where the signal going through the capacitor is added back into the audible signal.

[Jimmy Smith]

And not to get into it too much, but in this application the only thing that matters is the capacitor value. The signal going through the capacitor goes to ground and you never hear it.

So? The cap can still filter differently resulting in a different tone with the signal that is left.

[Herbie]

(…)
While we all focus on style, skills, and knowledge of the music and artists, I often wonder what, if any tone mods any one of the great Jazz players may have done or had done.
(…)

I don’t know but I think that most of the greats – and middle sized and small players – go with the stock rig (like Wes wanting a standard jazz box so if it breaks You can always find a spare) and some small percent like to tinker (like Les Paul, who invented all kinds of technique while being a famous musician).

I don’t know which camp Joe Pass was in. I’d believe he had to use all his spare time thinking of new fingerings and arrangements, so tech mods would’ve been last to think.

What becomes to Epi JP model my suspection is that the wiring and parts values has nothing to do with the Joe’s guitar, and they just used anything they had in the way they did those times when they did them.

I wish that someone knows better and I am wrong!

[JazzNote]

I don’t know which camp Joe Pass was in. I’d believe he had to use all his spare time thinking of new fingerings and arrangements, so tech mods would’ve been last to think.

A bass playing friend of mine who once dit some touring wit Joe Pass in Europe told me that Joe would not mind at all what amp he would be provided on the gigs, i would guess that he didn't care either about the value of the cap which was integrated in the tone control circuit of his guitar.

[icr]

I just looked through my stash of Gibson guitar schematics and most all of them show a 0.02 uF tone cap. Like this Johny Smith.

Sure there is a lot of variability as the tolerances are pretty high and they can change as they age. Like the real bumblebee caps in my Les Paul measure 0.06, but they are marked 0.022 with the stripes.

[Cunamara]

So? The cap can still filter differently resulting in a different tone with the signal that is left.

Only if the value of the cap is different. The construction of the cap (paper in oil, electrolytic, ceramic, etc.) doesn't have an impact on the tone, contrary to internet guitar myth. Indeed, some of the reissue PIO caps, etc., marketed to guitarists are ceramic caps decorated to look like vintage caps.

[sgosnell]

Capacitance is a standard electrical property, and easily measured. The materials the capacitor is made from don't matter at all, as long as they haven't degraded. Like any other device, some capacitors are manufactured to tighter tolerances than others, and to better physical properties. The material does matter, though, in that some materials do degrade over time. Oil in paper definitely degrades, and the capacitance can change, or they can fail. This is why old amps may need to be recapped - the old capacitors have just degraded to point where they are dangerous. Ceramic capacitors should not degrade like this, and should remain usable for the life of whatever circuit they're in. They can also be much smaller in size, which is an advantage in most applications. Insisting on oil/paper caps in anything is just religion - belief in an idea without proof, entirely a matter of blind faith.

[JazzNote]

I just looked through my stash of Gibson guitar schematics and most all of them show a 0.02 uF tone cap. Like this Johny Smith.

Sure there is a lot of variability as the tolerances are pretty high and they can change as they age. Like the real bumblebee caps in my Les Paul measure 0.06, but they are marked 0.022 with the stripes.

Very interesting schematic. I have never come across a Gibson Johnny Smith single PU version with a tone control.

[icr]

Wood, decals, inlays and finish can be duplicated/copied/faked, etc, but capacitors, potentiometers and wire are harder to fake. Thus my interest in original electronics when evaluating an old guitar. In terms of playability, most of that stuff needs to be replaced, though

[stevo58]

Capacitor tolerance is often 20%, not 10%. This will almost certainly be the case in any vintage gear. The dielectric is irrelevant until you approach the cap’s voltage limit. One notable
exception is cheap ceramic disk capacitors, which are often noisy.

Vintage values are different than modern values, so .02 (vintage) vs .022 (modern), .05 vs .047, etc.

20% means a cap rated .022 uF can be anywhere between .0176 and .0264 uF. That’s quite a spread - a .015 uF at the high end of the tolerance would have a real value of .018 uF - higher than a .022 rated cap at the low end. So either measure the real value, or buy a variety and clip them in until you find what you want (recommended).

Remember there is no way of knowing what value [insert famous guitarist here]’s guitar really had, even if stock, and it’s just one factor (pots, pickups have tolerances, and there is a complicated thing called an “amplifier” that has a significant effect, too. If you look at old Fender schematics, you’ll see they are all marked as 20% tolerance. That’s a huge range for a lot of bits.)