The 'Sound' of Capacitors..

Frequently asked questions on capacitor types, ratings, brands, use and abuse.
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Post by IvIark »

culturejam wrote:I think you are assuming the worst out of people. I'd love to see any test results on this topic. Further, just because it might be controversial doesn't mean the testing shouldn't be done (in my opinion).
With mictester in any thread I believe assuming the worst out of some people can be justified based on past experiences, and the test may well be interesting, I just don't think it'll prove or disprove anything.
culturejam wrote:I guess my real hangup, as I've said already several times, is that I just can't fathom how something that is clearly audible cannot be measured. If this phenomenon is real, there must be some way to observe and measure it. I cannot see how it could be otherwise. Perhaps we don't have the ability yet to measure it (which I find unlikely), but surely it can be done at some point in time.
Well you don't know yet that there will be no difference in the results, in fact I'd be extremely surprised if the final numbers were identical having played around with similar software in the past. But I think it would be difficult to get absolutely identical results even if you ran a recording of a clean guitar through the same pedal twice and recorded the results, which is why I think the final numbers will still be too open to interpretation.
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Post by culturejam »

IvIark wrote:Well you don't know yet that there will be no difference in the results, in fact I'd be extremely surprised if the final numbers were identical having played around with similar software in the past. But I think it would be difficult to get absolutely identical results even if you ran a recording of a clean guitar through the same pedal twice and recorded the results, which is why I think the final numbers will still be too open to interpretation.
So we're back to "It can be heard, but it can't be measured." And that's something I just don't get on board with. We'll just have to agree to disagree.

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Post by IvIark »

culturejam wrote:So we're back to "It can be heard, but it can't be measured." And that's something I just don't get on board with. We'll just have to agree to disagree.
No this is the thing, we're not back to that at all, it's not a collective opinion. I'll believe what my ears tell me but I'm not going to try to convince anyone to adopt my way of thinking, they should try it for themselves and make their own decisions, not base it on what you, or I, or anyone else thinks. There may be a way of measuring these things, but I'm not expert enough to say the best way to do it. If anyone really is interested in doing a Fourier analysis though, it would be very easy to do for your own curiosity.
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Post by RnFR »

yes, if you have anything definitive that you think you can contribute, please do.

btw- we should probably slide this discussion over into that thread.
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Post by marsens »

Maybe, the "caps sound" problem is like http://www.freemosquitoringtones.org/

Some people can hear the differences, and some people cannot.
People who cannot hear the high freqs maybe since the birth while some because some hearing loss.

When you cannot hear doesn't mean it doesn't exist (the differences)

Click the link above, let's know how is our hearing capability. I can hear all those but faintly at highest frequency.

How about you?

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Post by Drzeus »

That's how I see it.We're all made up basically of the same bits.Parts of my inner ear may be smaller than some,some bits may be bigger?.It's why I have a problem with shrinks.The idea is that every brain is the same and can be studied scientificaly.But we all think different things in similar situations.A+B does not always equal C,when dealing with subjective issues such as the human makeup.Some guys/girls can hear stuff other people can't.There are so many variables involved in hearing stuff that saying caps can't be heard or 'felt',can only be one persons opinion? IMO
Maybe the next 25 years won't go by so fast,when my soul is free at last

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Post by Skreddy »

Greg wrote:Kudos to Marc for coming and offering assistance with this..
Let's not get into the whole "cap type doesn't make a difference" argument again please.. it's been done to death.
:thumbsup
You can look at an oscillator sweep of ceramic caps and see the difference from poly film quite plainly--it doesn't even take ears. But if anyone cares to build a BMP on breadboard and sub out different cap types instead of arguing over the internet, they can listen and learn for themselves. I guess some folks can't resist the impulse to try to prove others can't hear what they hear, as if there were some important ethical or scientific value at stake?

I can see having a bit harder time hearing the difference between two different plastic-film type capacitors. But between ceramic and polyester film? Come over to my house and I'll show you; I have a breadboard already set up right here. Won't take but a second to demonstrate.

The whole "transistor type/gain" argument is another cute one I see a lot with regard to BMP's. "This bit of math proves it doesn't matter." Okay. Use high-gain transistors with 470k NFB resistors, 100R emitter resistors, and 470pf treble filter caps just like the classic schematic (designed when trannies had much lower gains) calls for. Won't sound harsh or fizzy or splattery at all. That's why mathematicians make such big bucks building guitar pedals. :hmmm:

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Post by culturejam »

Skreddy wrote:You can look at an oscillator sweep of ceramic caps and see the difference from poly film quite plainly--it doesn't even take ears.
This is exactly what I've been asking for in the past. But the answer is always, "You can't measure it with test equipment, but trust me, it's different."

So to hear you say that it's easy to prove is awesome. Can't wait to see the graphs and charts (from whoever would like to set up the tests).

Like Fox Mulder on X-Files, "I want to believe". :thumbsup

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Post by Skreddy »

culturejam wrote:
Skreddy wrote:You can look at an oscillator sweep of ceramic caps and see the difference from poly film quite plainly--it doesn't even take ears.
This is exactly what I've been asking for in the past. But the answer is always, "You can't measure it with test equipment, but trust me, it's different."

So to hear you say that it's easy to prove is awesome. Can't wait to see the graphs and charts (from whoever would like to set up the tests).

Like Fox Mulder on X-Files, "I want to believe". :thumbsup
A couple of years ago I did see a comprehensive evaluation with graphs showing how different cap types "look." Especially telling was tantalum, but ceramic had a distinctive signature compared to film types, as did aluminum electrolytic. But I think that site is gone now, and I don't have the equipment myself.

And I'm not saying math is wrong with regard to transistor gains--just that over-simplified formulae that don't take into account the various factors involving guitar frequencies and the introduction of distortion are missing important pieces of the puzzle.

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Post by dread pierat »

I remember a site like the one you mention, with x-y oscillograms showing polys with nice and straight lines and tantalums and ceramics with oval lines. I can't find the site now, and I forgot the url to put into the Wayback machine.

However there are other scientific sources, like http://waltjung.org/PDFs/Picking_Capacitors_1.pdf and the books Small Signal Audio Design and Audio Power Amplifier Design Handbook by Douglas Self.

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Post by culturejam »

Pulled the above posts out of the Cog Dis tracing thread.

I also had to remove mmolteratx's comments in his last post, so here's what he said (in reference to Marc's last comments):

mmolteratx wrote:Seen the same site, though I can't remember the name. Last time I saw it was around a year ago, I think diagrammatiks posted it on another forum. I'll see if he still has it. Ceramics were wildly different from everything else IIRC. And there's definitely a difference in cap composition, though I don't notice a difference between multiple brands of the same type like some claim to hear. It isn't always super apparent when switching out just one but switch them all out (even if you measure the values to be exactly the same with an LCR meter) and you should be able to hear it.

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Post by diagrammatiks »

I can understand how people will say that they don't hear a difference in caps...

but then for someone whose an engineer or "whatever" come in and claim that there is absolutely no difference in capacitors types, materials, or construction methods is just mind boggling.

of course the test they always do is the sine way sweep. hey look the sweep looks similar. or they'll play a single frequency and say hey it all looks the same on the scope.

this of course discounts the blindingly simple and very very basic fact that all parts of the circuit including the components are dependent on frequency, amplitude, and differential response.

but then they'll say but hey that only matters in the gigahertz range all the standard tests show that it doesn't matter at audio frequency...

which is a valid fact except that none of those tests are about components undergoing and passing extremely distorted square wave signals and anyone who says otherwise is a liar.

either that or they are hiding the big book of valve and transistor behaviors under extreme rail to rail conditions. that shit would be golden.

anyhow...capacitors are different. the spec sheets say they are different. they all have different dielectric properties and behaviors.

that's like chapter 1 of my electronics for dummies books in a little side box called "understanding the difference between ideal and real components" literally they spend like a paragraph on that shit because it's so fucking obvious.

the end.

culturejam wrote:
Skreddy wrote:You can look at an oscillator sweep of ceramic caps and see the difference from poly film quite plainly--it doesn't even take ears.
This is exactly what I've been asking for in the past. But the answer is always, "You can't measure it with test equipment, but trust me, it's different."

So to hear you say that it's easy to prove is awesome. Can't wait to see the graphs and charts (from whoever would like to set up the tests).

Like Fox Mulder on X-Files, "I want to believe". :thumbsup

the graphs are out there. but you're never going to see one that says here is the difference and this is what you'll here.

that's because the fact that they behave differently is something that isn't debatable.

build a switchmode power supply with nothing but fender blue molded caps if you don't believe it.

at the end of the day it doesn't really matter if some one's ears are able to prove it conclusively, especially over a youtube or internet clip.

the difference does exist and it's measurable.

keep in mind that this doesn't mean that you can just drop in a cap or switch a cap out and expect differences automatically.

that's the difference between replacing parts and designing around parts.

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Post by RnFR »

:popcorn: that's not a sarcastic popcorn, either. :D
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Post by SpencerPedals »

When I was building my Mayo clone I was very skeptical that transistor types played a huge difference in Muffs simply because the distortion is not set up to come (mostly) from the transistors being overdriven. But in reading dozens/hundreds of Muff threads and having ordered over a half-dozen types of transistors, I decided I had to give it a shot for myself (sockets), and would still encourage anyone to do it. This is almost always shrugged off as you hearing a gain difference, and, while you CAN tell when a transistor set is pretty "gainy" in this circuit, it is entirely possible to take two sets of transistors in the same gain range (measured by an Atlas DCA-55) and tell the difference. Not all transistor types, but definitely some with very similar gain ranges. There are my two cents with regards to the BMP circuit and real-life testing.

I have not done cap-type testing, but have some ideas in mind for this circuit, and the weather is cooling to the point where it has stunted my outdoorsiness for the next ~five months. I'm back to soldering and, soon, breadboarding.

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Post by culturejam »

diagrammatiks wrote:the graphs are out there. but you're never going to see one that says here is the difference and this is what you'll here.

that's because the fact that they behave differently is something that isn't debatable.
Okay. I'm with you here.
diagrammatiks wrote:the difference does exist and it's measurable.
I'm not arguing this point. It makes sense to me that difference dielectrics might somehow make a difference in sound. I mean, I guess that capacitance isn't just capacitance at a given value. Right?
diagrammatiks wrote:keep in mind that this doesn't mean that you can just drop in a cap or switch a cap out and expect differences automatically.
Why not? If the difference exists, and it is measurable, then why can't I hear it the difference by swapping out the thing that is different? This isn't a smart-ass question. I really want to know. I want to believe that there is a big difference between cap types; I really do. It would make things so much easier if there were clearly superior cap type.
diagrammatiks wrote:that's the difference between replacing parts and designing around parts.
So if I design my circuit in way that emphasizes a difference in the sound of ceramic over polyester, then I'll hear a difference? Okay, I can believe that. The trouble is that I have no idea how to do that. Can you explain some design rules that might assist in designing a circuit to make one cap type sound different from another? That's something that would go a long way to explaining/demonstration the differences.

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Post by diagrammatiks »

culturejam wrote:
diagrammatiks wrote:the graphs are out there. but you're never going to see one that says here is the difference and this is what you'll here.

that's because the fact that they behave differently is something that isn't debatable.
Okay. I'm with you here.
diagrammatiks wrote:the difference does exist and it's measurable.
I'm not arguing this point. It makes sense to me that difference dielectrics might somehow make a difference in sound. I mean, I guess that capacitance isn't just capacitance at a given value. Right?
diagrammatiks wrote:keep in mind that this doesn't mean that you can just drop in a cap or switch a cap out and expect differences automatically.
Why not? If the difference exists, and it is measurable, then why can't I hear it the difference by swapping out the thing that is different? This isn't a smart-ass question. I really want to know. I want to believe that there is a big difference between cap types; I really do. It would make things so much easier if there were clearly superior cap type.
diagrammatiks wrote:that's the difference between replacing parts and designing around parts.
So if I design my circuit in way that emphasizes a difference in the sound of ceramic over polyester, then I'll hear a difference? Okay, I can believe that. The trouble is that I have no idea how to do that. Can you explain some design rules that might assist in designing a circuit to make one cap type sound different from another? That's something that would go a long way to explaining/demonstration the differences.
I think that the thing that fills my mind with the most **** is that capacitance of a capacitor dependent on it's frequency over impedance graph.

Practically, all that it means is that if you look at two different cap types of the same value say .022, the math will give you a -3db roll-off frequency.

The differences between the two caps will determine the actual shape of the frequency plot.

As for hearing differences, for me, it's a very small detail that becomes more apparent the more you listen for it. The thing is that it won't change the sound across the entire spectrum all of the time.

Considering that an effect/amp responds to multiple shifting input frequencies, changes in stage frequency responses will manifest across parts of the spectrum some of the time.

As for building with ceramics versus polyester...
that's one of the places where differences in production and dielectric quality becomes pretty apparent.

ceramics around the 1uf value are usually of very poor quality and will function at the capacitance some of the time for some frequencies.
A very good ceramic cap can be very close to an ideal capacitor but is very expensive. It'll also give you searing piercing highs that'll make your ears bleed.

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Post by culturejam »

I guess I'm just not smart enough to understand what you're telling me, because I keep failing to see a way to demonstrate some palpable difference between cap types.

I get it that caps can and do yield different capacitances over different frequency ranges. I just don't understand how that translates to ceramic vs polyester in a Fuzz Face or Big Muff circuit. I think I need somebody to just simply "connect the dots" for me as to how it all works in the context of something I'd actually use (like a fuzz, or a phaser, or a headphone amp).

But I'm very willing to learn. I do mean that in a very serious/honest way. I feel like there must be some big difference that I'm just not understanding, and it pisses me off!! :lol:

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Post by diagrammatiks »

i think that if it was really super easy to figure out that stuff beyond what the math was telling us well..things would just be a lot easier.

i like red caps.

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Post by Skreddy »

culturejam wrote:... I keep failing to see a way to demonstrate some palpable difference between cap types.
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Post by NQbass7 »

The most important thing in any type of testing like this is that the person listening for a difference doesn't know which one is which.

If you give people two bottles of wine with identical wine in them, but different labels and different price tags, they will tell you almost every time that the more expensive one tastes better even though the wine was identical. People invent a difference that isn't there.

Any type of subjective test has the same problem. You have to make sure it's a blind test - double blind is even better - in order to be sure of any result at all. If someone posts blind A/B links of different capacitors, and then has the entire forum listen to them and vote on it, and almost everybody chooses the same one - then I might believe it. (In fact, you'd have to remove other sources of error too - like having half the people listen to Poly first and Ceramic second, and the other half listen to Ceramic first and Poly second to make sure they don't always pick the second one or something.)

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