Capacitors read uF but don’t work in tester

[frets]

Fellas,
I’m sticking my neck out on this one because it may result in Cindi jokes (which are fine and funny). This one is weird and absolutely true. I need help understanding this conundrum.

I occasionally build my own copper foil capacitors for builds because copper foil capacitors a haughty taught; and, I think they sound better.

I just built three capacitors. Using the same process, but using different wire, I used copper wire for the leads. Sanded them.

The problem is, these capacitors I’ve made register on two uF meters....repeatedly; and, at the same values. However, when I put them in my test guitar, they shunt nothing, no tonal action.
This seems impossible to me. The only thing I’ve changed in making them is the use of the copper wire. I know the tester is good because I subsequently tested it. To recap.
- copper foil capacitors
- with copper leads
- waxed
- uF reads in two meters at the same levels (given standard margin of error)
- put them in my tester guitar, that I know is functional.
- Bupkus, no change in tone.

What the Sam Hill is going on?

[sumgai]

frets,



First, I'd like to see pictures of your process for making these things. That is, if you have someone to "look over your shoulder" and click the shutter, so to speak.

Second, when you say "the meter shows a value in the μF range", what is the exact value? As you know, if the cap is too large a value, or too small, then the range of action is compromised. So, what do your meters read?

Third, I'm gonna go out on a limb (myself) and ponder the thought that there's an additional reactance here of which you are not aware.  I'd try this: set up a simple one-stage amplifier circuit, power it with at least 4 or 5 volts, the more the better.  Drive it with a signal generator capable of DC to 20KHz, perhaps much higher if your generator does go that far.  Insert the cap directly in the signal path at the output, and see what happens to the tone.  Much, much better would be to use an oscilloscope to observe the waveform.... but I understand that not everyone has one of these jobbies just laying around.    Still, your ear should give at least a rough indication of what's what.  Don't forget to sweep the frequency generator's range, a single frequency isn't enough to tell you what the cap is capable of doing.

HTH

sumgai

[frets]

Sumgai,
I actually have the equipment to do that test!
Process:
99.8% Foil
Kitchen Parchment Paper (lower wax content, dielectric)
Solder the leads to foil
Test before waxing
Dip in hot bees wax
Re - measure two times on two meters.
Take mean
Test in my guitar tester for sound

Values this time
.015
.020
.042
I’ve become very proficient on hitting my desired marks.

Description
Look like something that Vincent Price would make in the “House of Wax”

Why?
Because I believe copper foil caps sound the best.
/t3h94w7

I will Test !!!! And Return , To bore you some more !!!

[JohnH]

This is really great! super nutz!

If the finished caps then make no change of tone when wired in, here's my tboughts:

Maybe some of the likely issues are that the cap becomes either shorted out inside or disconnected. But a shorted cap (ie acting as a wire link), would still result in large audible changes on sweeping a tone pot, ending up with no sound at 0. So can't be that. How about if leads became disconnected? does the fab process involve soldering copper wire to each copper foil(EDIT..I See that it does) ?

Or, maybe the cap values obtained are coming out much less than expected. Could the meter be reading to a different scale than thought? A few picoFarads might still give a reading but not be audible.

[frets]

John, they are reading in the same uF range I always hit. I don’t know what to say, it is totally Nutz. I am going to try Sumgai’s recommendation; but, this outcome on the tester only started happening with these leads. I will say my house is haunted and this could one of Elva’s many pranks. She usually takes things but also enjoys electronic misdeeds. It’s the best I got. Ha! I’ll retest.

[b4nj0]

This isn't boring frets- it's great (or nutz!)

May I enquire? are these of two layered spiral construction or multi layered flat?

e&oe ...

[blademaster2]

Frets, you are the only person I have ever heard of who actually fabricated capacitors on their own. That is impressive, and amazing. No "Cindi" quips would be appropriate in any situation (I would object to it regardless), but anyone inclined to show you such disrespect would have no basis to do it here.

Unless you used a lot of copper foil area and a very thin wax paper for the dielectric (not the kitchen variety) I would intuitively expect that the capacitance would be a pretty low value and not in the uF range. Hence my first suspicion is that the value was too low for the tone control to make a difference - and I cannot explain why the meter showed differently, but capacitance readings are more complex than resistance readings for these things and there are a few things that might explain it.

Otherwise, an open circuit as JohnH suggested might be the cause.

As to the idea that copper would be audibly better than other metals, I do not expect to hear it or see a measurable difference in instrumentation, but I would also never tell someone that they are not. Human hearing is one of the most fascinating senses.

[frets]

Blade, Thanks for being so thoughtful on this crazy event.  I only use Copper Foil, PIO’s and Orange Drops on builds that customers commission.  I do think I hear a difference, but if I was placed under a blind test I don’t think I’d be able to hear the difference between any capacitor construction. I’m going to pitch out the crap caps and move on.
More weird that the phantom capacitors is how I collect capacitors.
Right now, I’m trying to add to my Russian PIO coffers.  These are just my .022 and .047’s with some random Polypropylenes.  Ha !!

[JohnH]

Feb 3, 2020 11:54:49 GMT -5 frets said:

Blade, Thanks for being so thoughtful on this crazy event.  I only use Copper Foil, PIO’s and Orange Drops on builds that customers commission.  I do think I hear a difference, but if I was placed under a blind test I don’t think I’d be able to hear the difference between any capacitor construction. I’m going to pitch out the crap caps and move on.
More weird that the phantom capacitors is how I collect capacitors.
Right now, I’m trying to add to my Russian PIO coffers.  These are just my .022 and .047’s with some random Polypropylenes.  Ha !!

mmmm a capacitor candy bowl!..I might just help myself to a handful to munch on...

[frets]

Anytime you guys need some, just let me know. Don’t pay those outrageous EBay prices, believe me, I can spare some.

[Deleted]

are they all paper and oil ones! hell of a collection
never pictured making own caps

[b4nj0]

Blademaster is right on the scent here, the uF is a pretty large value, and unlikely to be duplicated with kitchen table technology in any sensible size. This is why I asked about the nature of construction because I couldn't tell from the images of those wax potted components. Sometimes meter readings need to be interpreted rather than taken as gospel, and I would focus on that first. Look at guitar cable as an example, we compare values of 30-100 pF per metre quoted on various manufacturer's offerings and talk up one brand over another, yet your home made ones are managing perhaps one million (edit: thousand!) times as much capacitance? Ignoring voltage requirements, capacitance is dependent upon area, inter "plate" gap and dielectric constant, you would indeed need thinner than kitchen parchment dielectric to even think about it. I cannot explain why or even how your previous succesful ventures worked using other than copper wire though. Threads like these are the life blood of a healthy forum, so thanks are due.

e&oe ...

[frets]

b4

Spiral type that come out as book caps.

[frets]

This proves everything is grounded in logic.

My great capacitor conundrum is solved. The meters are correct, the caps are good, it’s the external tester that had an intermittent short.  Intermittent Short? It was a sneaky little short; whereby, the solder ground on the male jack wire had just wiggled loose slightly inside the jack. I’m sure many of you know how hard it can be to get these grounds to stick inside the jack “L”. Especially with the cheapo Chinese ones. Anyway, the weight of the copper foil caps whilst dangling from the green (ground) - see picture - alligator clip pulled the solder ground so ever slightly away from the jack casing wall; thus, breaking the circuit.

Putting a box type Wima cap( to compare to see if it mine were faulty caps I made) is light, and allowed the solder ball short to scoot over, retouch the wall , and make contact with the jack casing on the inside - and allowing it to shunt. Put my copper foil waxies back on - and “short,” no shunt. Case closed. I hope that made sense although it’s really not important.

I sorta was hoping that it was my Ghost....Elva.  No, it was an airhead brunette.

[sumgai]

Frets,


Ah yes, the devil is always in the details, ain't it ever so true.

Good find, and good troubleshooting skills.





sumgai

[frets]

Thanks Sumgai, you guys had me walk the line as Johnny would say. Finally got there.

[b4nj0]

You questioned what your eyes and ears were telling you and that is commendable. (Would that more folks questioned what they encounter without any thought.) I had a similar gotcha with a guitar jack socket, the manufacturer had used a switching amp input socket and the tag I needed was concealed beneath wood so I wired to the switching tag by mistake not suspecting there would be a third. This meant it rang out properly on the bench, but had no sound when plugged in. You don't want to know how long I wrangled over that and it was because I was forced to use a Weller 100 watts soldering gun to solder the base back onto a P90, so I immediately figured that I had demagnetised the pup. How wrong can you be? Excellent result for you frets and I'm looking forward to more about kitchen table capacitors. I have to say I'm a Doubting Thomas regarding capacitor types because capacitance is a physical property. Those Orange Drops (sic) just happen to look cool!

e&oe ...

[frets]

B4nj0,
Thanks for the nod, but your situation sounds a 1000x worse.
Caps have become this weird collectible for me and I don’t know why. But I really don’t know which sound best. I use smd caps to PIO’s. But when you make a build, guys expect Orange Drops, PIO’s and Copper Foil Caps and I’m not paying what they want for copper foil caps.

[reTrEaD]

Feb 6, 2020 12:41:35 GMT -5 frets said:

B4nj0,
Thanks for the nod, but your situation sounds a 1000x worse.
Caps have become this weird collectible for me and I don’t know why. But I really don’t know which sound best. I use smd caps to PIO’s. But when you make a build, guys expect Orange Drops, PIO’s and Copper Foil Caps and I’m not paying what they want for copper foil caps.

I doubt you'll be able to hear the difference between the best and worst caps in a treble-cut control in a guitar, because of the way it's configured in the circuit. Maybe in a bass-cut circuit, though.

You might find this of interest:
The Sound of Capacitors

[sumgai]

[EDIT: Ninja'd by reTrEaD!)

The sad part of all this is, the standard tone control is a bone-stock treble cut device. Seeing as how the upper frequency range is being shuffled off to Buffalo, or ground if you so prefer, then what remains is what goes out of the guitar. Per force, that is what the listener hears. Meaning, if a cap has "special" properties, then it's the ability to be selective in what it can shunt to ground, not what it allows to be passed on, and eventually heard by the listener.  Ooh, wait, I just described every capacitor ever made, didn't I?

To me, the only property I'd deem worthy of bother would be a very tight value tolerance, and one that doesn't wander around thanks to temperature.  And yes, some folks play outdoors in all kinds of weather, which in turn can change a cap's value, and thus affect the tone. Which is why there's a rheostat in the circuit, to (somewhat) adjust for this phenomemon.  There are standard caps made to take care of this kind of thing, you'll find them labeled as "NPO", C0G, or some other similar designation - they are much more temperature stable, but they aren't your ordinary Orange Drops and such, they are ceramic, and they cost a tiny bit more (than a regular cap, certainly not more than an "Oooh, shiny!" cap).

Where there is a noticible problem with some caps is those made with polypropelene plastic.  These seem to be "noise driven", in that they change value as the incoming signal voltage varies, and the resulting tone shows it.  But to my ears, every other kind of cap construction sounds the exact same.

</today's lesson>

EDIT: I should've mentioned polystyrene as well, and probably most of the other capacitors using some kind of plastic as the dialectric... they're pretty much all in the same boat, noise-wise.  (Noise not being defined as some kind of interference getting in, but defined as a wandering capacitance value that makes the output progress from one tonal palette to another, and then back... or to yet another.... you get the idea.)

sumgai

[frets]

Retread and Sumgai,

I’ve always been leary to admit what construction of capacitor sounds better. I’ll do it knowing my own personal data doesn’t support it. In fact, Retread’s linked study is the first I’ve seen that indeed, states differences between the materials to make the plates or the manner to which they have been treated, results in terms of differing tested outcome. I’ve often read that the differences we hear in capacitors is attributable to slight differences in the values being tested. However, that article is compelling.

In a blind test conducted by a fellow capacitor nut, using caps of all the same values, within a small standard of acceptable error, my results were not reliable. The only sole one I selected as consistently being the worst was the ceramic disc; yet, I could not make the same basic distinction with a smd ceramic.

I know what Sumgai says (quite eloquently) is fundamentally logical; yet, Retread’s referred to article is , as I said, “compelling”, and is what I want to hear I.e., - a difference favoring PIO’s.

In a guitar build for sale, the capacitors always have to be non-metallized polypropylene, PIO’s, and recently the addition of customers asking for copper foil (that cost a ton). So, that’s what they get. You can’t change their opinions and usually they decide on the advice of someone else.

Then there’s the potential for caps made out of the same materials but by different manufacturer, may sound or test differently....or the same.

In a small tangential way, cap comparisons always remind me of interesting pickup comparisons with pickups made of the same materials; I.e., potted, nickel backed, Alinico V’s; but, with huge price differentials. I’m not saying that all pickups sound the same, I’m just stating that the same materials used and the subjective ear of the beholder has a lot to do with the appraisal. For example, potted pickups with the similar Alinico V magnets. I can’t tell the difference between a set of Seymour Duncan JB’s and SH4’s compared to a set of Donlis DH53’s. Both sets with similarity in construction. But there most likely is a technical difference. Nor can I tell the difference between a set of Fender VooDoos vs. inexpensive Pribora VooDoo’s. . Is there a difference - audibly?

Likewise with caps, they may sound the same, but a technical difference as exampled by Retread’s link
should be valid given the testing methodology.

What I’ve said will most likely generate a lot of controversy.

[sumgai]

frets,



No, not much controversy.... at least not amongst the cognoscenti. Those of us who use reason and logic understand the phenomena of mouth-breathers thinking that they have stumbled onto the "perfect sound", or "the next big thing", etc. It's a societal thing that we have to live with, seeing as the alternative is no guitars are allowed in Crow-Bar Hotel.

The linked testing (I read through it quickly, not digesting absolutely every paragraph, but absorbing the gist) shows in the images exactly what's happening for each type of cap. Translated to the real world, we can just about guess which cap types might not sound like the remaining ones. But as reTrEaD will back me up on this, no matter how rigorous the lab testing, such results never really translate directly to the real world. Close, usually. Exactly, never. But they do make a good starting point for those who wish to investigate a little further than "my (hero of the day) plays with XYZ, so if I use that as well, I'll be famous!".

I appreciate your honesty in admitting that blind testing creates the conundrum that you can't discern most caps from others, that's a difficult thing to do. Now you understand my insistance that only double-blind testing, with a large sample base, is truly indicative of likely dependable results.

HTH

BTW, I have thoughts on modding and custom building.  They've changed over the years, so this thread would not be the time or place for expressing such.  Perhaps I'll start a thread in the Covfefe Shop.

sumgai

[newey]

The meters are correct, the caps are good, it’s the external tester that had an intermittent short.

I misread your original post- you checked them with two meters, I thought you had said you used two separate testers.

I had half-typed a post suggesting that you "test the testers", but I thought "they can't both be bad, the odds are astronomical"! So I didn't post it.

Glad you solved the puzzle (and debunked any Elva involvement, lest certain reality TV guys show up at your place with a lot of weird electrical boxes with VU meters and lots of knobs).

[frets]

That is way funny, Zak Bagans in my dining room for a week with a spirit box, “Elva, where did you put those Barden Pickups?”

[b4nj0]

I have original production run Bardens in a Gatton signature I screwed together. They are awesome pups. Antigua has glossed over them once in a post, but I wish he'd give them a good work out. Kinda selfish I know but ...

e&oe ...

[sumgai]

Feb 6, 2020 21:41:08 GMT -5 newey said:

I misread your original post- you checked them with two meters...

First thought I had was "I wonder how b4nj0's gonna make a joke out of that one."

(If you don't have a foot warmer under your desk, then you are safely out of the Ham-zone!)

KA7ZPS (retired) (but starting a new career in derailing threads!)