The Truth about Tone Capacitors

Discussion in 'Tonefreaks' started by Rodolphe, Dec 4, 2013.

  1. woolenmammoth

    woolenmammoth Senior Member

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    I dont dare bring tape into this, but this is wildly poor information. Tape absolutely degrades over time, but the real problem is the chemical compounds breaking down that hold the oxide to the backer. During the process of making something like, a rock record, the length of tape that that 3 minute song takes up will get dragged back and forth across heads and guides hundreds and hundreds and hundreds and hundreds and hundreds of times. The mixed master on the other hand is never played nearly (as in not remotely nearly) as much, you print it, it gets listened to, a mastering engineer plays it a few times and that it. In a professional recording situation if you are having problems with signal degradation you have bad tape (which happens) or something else is the problem. Beatles masters are still playable, its an excellent long term storage medium. There are warehouses of perfectly playable tape (without baking) that completely outlasted the electronics of some of the professional decks they were recorded on. Try dealing with a scully 280 today, no thanks.
     
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  2. Armitage

    Armitage Senior Member

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    The funny thing, hi end audio manufacturers argue which cap type/brand etc sounds better and whether different caps make a difference in audible tone. And those amps have hundreds of caps in them and your tone actually goes through most of them. While in a guitar there is only one cap (per pickup choice), and only the tone that shunts to ground goes through it, not the stuff that gets fed to your amp. I'm not saying there can be zero interaction, just saying if people still argue that hundreds of one or the other might make a difference... one would be pretty insignificant. If you want to change a cap that makes a difference, it should be the first one in series with your tone in your amp... yet no one does.
     
  3. boyscout

    boyscout GAS study patient member Premium Member

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  4. Quill

    Quill Senior Member

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    Well ... digging around inside an amp is quite dangerous, whether you know what you are doing or not; and so far, I don't think anyone has hurt or killed themselves while tinkering with their guitar's wiring. So there's that.

    I do agree with you that the impact of the caps' qualities on the sound of the amp is huge, and crazy-making. Let's not even start on the resistors and the grounding and the lead dress ... however, I really don't know whether caps-in-amp changes make more noticeable differences than caps-in-guitar changes; the simple RC network in the guitar hits that signal pretty early and pretty hard - it's important! And it also depends on how we use our gear - are we working one or two guitars through several amps, or several guitars through one or two amps, what effect are we going for, on and on and on. Depending upon our set-up, the cap materials might not matter one bit, or they might matter a lot.

    I've tinkered a lot with the caps in both guitar circuits and amps. Changing caps has an effect, to my ear, some more than others, in all kinds of different ways ... it can be really difficult to keep it all under control. And do we need to control it that precisely? Anyway where I was going with this was that I learned about what to try largely from reading around in MLP posts, especially in Squawk Box - so I'd say a lot of players, especially those with some electronics experience, experiment with their sound in every possible way they have the time and patience to spend. And speaking of spending ...

    Here are the results of my own trials and errors in my home-assembled 5E3 clone - which came stock with SOZO caps. Which sounded great! What I have in there now is a very different great, and makes a more interesting difference between the Bright and Normal channels for what I do with the amp.

    [​IMG]

    Both those caps were in guitars, and I loved them there but find they hit the sound differently in the amp, and it works for me to have them there. They are not cheap so I decided to put them there kind of to maximize their potential - they have such a beautiful quality to them, having them in my amp lets me incorporate that sound detail into the amplified sound of all my guitars!

    I loved that 0.047 on the bridge pickup of my LP and miss it sometimes ... really nice to work with. I'd put those big Jensens in everything if I felt I could justify the cost - I guess it wouldn't cost that much, I'd only need a handful. But there are so many caps that sound good in a guitar - I had no trouble finding one from my collection to nicely replace that Jensen. It was an old NOS American-made cap I got from Jonesy (for, by the way, a fraction of the cost of the Jensen) that did the trick.
     
  5. KenG

    KenG Senior Member

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    I went back and talked with one of senior designers and he had quite a chuckle but said something that makes me want to partially agree with the PIO argument to a degree. The "perfect" capacitor is actually COG NPO as it has all the best characteristics with the minimal detrimental side effects. So if you want the "true tone" of your guitar this is the cap that will not do anything but provide capacitance.
    Paper in Oil though he stated may really introduce distortion (as a previous poster mentioned but did not explain) through a very undesireable characteristic of a basically poor capacitor design known as the piezo effect where signals applied cause the plate spacing/dielectric performance to change and therefore change the capacitance across the frequency range. No designer looking for accuracy in a circuit would chose this knowingly. Same as the "resonance" effect, capacitor resonance is in the high frequency area where minimal properties like lead inductance become more "real". This affect does not occur in the audio band or anywhere near it and again no designer would use a capacitor in a circuit that operates in the caps resonance so this one is a non-starter.
    So it may simply be that this normally undesireable side effect of PIO (piezo) is actually working for some people because it alters the sound in a way a capacitor is not supposed to.
    This is one of the reasons I would've liked to see a real experiment with just caps, resistors and analyzers used.
     
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  6. David Collins

    David Collins Senior Member

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    Ken - did you mention to your friend that the capacitors of concern here are generally 50-400 volt ratings, used in a circuit that rarely exceeds 300-500 millivolts? The piezo effect may be of real concern in other applications, but I doubt it has any potential to come in to play in a setting like this.
     
  7. woolenmammoth

    woolenmammoth Senior Member

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    Ken-

    do you have an AP? You can hook a cap right up to it and sweep it and measure its distortion. This isnt like, black arts or wizardry or anything. It draws a picture right on the screen...

    While low distortion is a wonderful tool for people to market audio equipment with, I dont know a single designer with a career in audio who isnt designing FOR distortion. Hifi has spun off into doctors with class D amps in their living rooms, which will make ya cock your head a little but in guitar world, this is all about distortion. I would also bet that teflon would beat out COG/NPO but obviously size wise there is no comparison.

    your posts read like a true engineer and thats wonderful, but have you ever designed an audio circuit? The reason why so much of new gear is so boring and flat sounding is because COG is the primary cap available to use in surface mount. You will not find a person to disagree that it measures better and is "superior" in most ways. What you will find is an internet full of bummed out recording engineers who buy new stuff for top dollar and are dissatisfied. One of the primary reasons is the sudden prevalent use of COG. If it was so amazing, people would have been using it everywhere in through hole, but they were chosing other caps.

    Before you go waving the COG flag, you might consider one thing first: These caps have been available for many, many, many years. They always measured good, they always looked better on paper, they were mostly always cheaper than anything you could get in pf range. You had an engineering department that would be seemingly pushing for them and an accounting department that would be pushing for them, yet, for years, maybe 20, you had the worlds number one microphone manufacturer using styrene instead of COG. The universe agrees that COG is "better" than styrene, yet, the people designing those mics could have spec'd COG and they didnt. And then they moved their production over to surface mount, they use all COG, their new mics are abysmal and there is RAGE directed at this particular company. And the layman out there can't understand at all why the new many thousands of dollar mic sounds brittle compared to the old version, of the exact same mic which was made through hole which sounds way better in comparison. An internet full of dissention on the topic. They could have been using COG all along and didnt until they HAD to. They still make one mic that is through hole and last I looked there wasnt a single COG cap in it. More accurate is not always more better.

    I would be so bold as to suggest that only a fool would design audio for music with a zero distortion goal in mind. You could argue this until you are blue in the face but the simple fact is that the most expensive recording gear you can buy is hardly anywhere close to low distortion. People could make records with measurement microphones and they dont. Classical music people dont even get excited about measurement microphone recordings.

    There also isnt a single guitar player alive that wants the "true tone" (whatever that is) of their guitar, if they did, they would all be recording direct. What people want is something that sounds GOOD.

    Additionally, if you have designed audio circuits, Im sure you have been in a scenario where you had oscillations in the Mhz effecting the performance of opamps. Actually THAT is where COG caps come in handy, as snubbers. There are things in some circuits that occur WAY above 20K that can effect the audio band.

    All my statements here can be supported with market research. There are lots of people making high end digital converters now. Lots. And there is one company that added a transformer (for distortion) and has an audio circuit that is significantly higher distortion and dealers can not keep these units in stock. Those guys have been on fire for such a sustained amount of time it would be impossible to dismiss it as a fad.

    Ive yet to meet audio designer concerned with making a good sound that is looking for sheer accuracy. We arent designing test equipment. We are designing stuff that sounds good to people and with the most minimal effort it is very easy to see what people are demanding, what people are frustrated with and why. Distortion converter guy carved a huge section of the market for himself simply by listening to the people and getting his head out of engineering.
     
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  8. captcoolaid

    captcoolaid Senior Member

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    In the world I live in which is of the lets say more metal style of play, most caps sound the same. The biggest difference that my ears can discern is in the roll back. However that being said on my guitars I canm tell the difference going strait to jack and with a cap in line. Could I tell if say Dave Collins was doing it, nope because it is not my gear.

    Now I can tell you my likes and dislikes in various caps K40s, Aerovox, and a few others and ones I did not like Jensen and those shite little chicklets.

    To me the biggest difference is not always the cap but the whole chain from pup to jack on the guitar bust mostly pot vs caps.

    Just my $5811 dollars worth.
     
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  9. captcoolaid

    captcoolaid Senior Member

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    On a side note could anyone identify a capacitor in anothers rig if they did not already know. If the tone is there it is there period.

    I mean what if Heartbreaker was done with a Tele with a single coil and a paper in wax cap instead of a LP and set of PAFs and real bees. Would you be able to tell the difference. Oh wait it was done on a Tele and most if not all could not tell. See what I mean.

    Tone is subjective no matter how you look at it. The cap is but a tiny part in the food chain. I can understand from say a vintage correct aspect of it the need for accuracy in replicating but like someone else said earlier you, your guitar or the audience will not and can not discern between a 200v, 400v, or a 50v cap And to me that is the truth about tone capacitors.
     
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  10. David Collins

    David Collins Senior Member

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    I fully agree that if you picked up a stranger's guitar and played through their rig you had never used before, the odds of being able to identify specific details like pot or cap value or pickup type are pretty much nil.

    If a change is caused by the cap however, do you not think that if it were switched in real time while you were playing that you should be able to pick out a subtle difference?

    The key here is the difference between identifying relative real time change vs judging final tone. Even if you are not intimately familiar with a particular setup, it should not take much of a change to identify a difference when you switch that setup between A and B in real time. This is not asking which type or value it is, but simply playing samples side by side and seeing if you can hear any difference at all between the two, which shouldn't take too much familiarity with a particular rig if a noticeable change is indeed affected.
     
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  11. captcoolaid

    captcoolaid Senior Member

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    David that is a great post, and I do agree whole heartedly. At 10 there may not be a huge change but some pending the cap value, but at the time of roll off I firmly believe you can tell between a good cap and a crap cap.
     
  12. Armitage

    Armitage Senior Member

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    That's the only way to actually check. Just by putting a guitar down and picking it back up can change the way you're holding it, the angle of the pick, and the pick attact.

    A rotary switch with someone else changing it where neither of you know which cap is which... IMHO anywayz.
     
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  13. El Kabong

    El Kabong Senior Member

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    I have an Epi 345 with a rotary tone switch and it would be interesting to actually rewire it with 6 different caps to compare the output of each while all the other factors and settings remain constant. Its not a Les Paul and I would probably want to put in some real pickups while I was at it, but it might be an interesting project for the new year since I don''t really use the rotary anyway... perhaps a direct comparison the following 6 caps would be pretty cool.

    A comparison of my favorite caps would be one way to go...

    1 - Vintage Sprague Bumblebees
    2 - Luxe Repro Bumblebees
    3 - Sprague Black Beauties
    4 - Sprague Vitamin Qs
    5 - Sprague Orange Drops
    6 - NOS Russian K40Y-9 PIO

    A comparison including ceramics, mylars, and the various caps pulled out of my MIJ LPs would also be interesting for comparison's sake...

    I wonder if one of our guys here could actually pre-wire such a beast... :hmm:
     
  14. Brocko

    Brocko Senior Member

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    The thing is it is all irrelevant unless you conduct a 'double blind' study, where the experimenter and test subject don't know which cap is being used, check all the cap values are the same, use a consistent tone generating device (as attack, pick angle can affect sound) and also use enough test subjects - then run some statistical analysis on the results.

    I suspect regardless of the result of that, both sides of the argument will still swear they are right and find reasons to back it up!!!
     
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  15. northernguitarguy

    northernguitarguy SWeAT hOg

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    Just look at all the inputs that have to be strictly controlled to hear anything, and I'm sure there are more. This is why I am skeptical of people who rave about the tone changes from a cap swap. Are they playing live with a band, or are they on their beds, doing everything possible to hear any change? It reminds me of this, especially at 2:48.

    [ame=http://www.youtube.com/watch?v=8Zqe4ZV9LDs]Penn & Teller: Bullshit - Organic Taste Test - YouTube[/ame]
     
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  16. Alligatorbling

    Alligatorbling ★AstroCat★ Premium Member MLP Vendor V.I.P. Member

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    forget caps, hell... forget tone knobs.... shit, screw it... forget volume knobs!

    neg and pos from pickup straight to the jack ftw :dude::dude::dude::dude:


    :laugh2::laugh2::laugh2:
     
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  17. skindley

    skindley Premium Member

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    :lol:
    An observation about the "test subject". Is it the capacitor or someone listening to the sound? Unless you are attempting to "measure" human perception I would think the subject of the test would be capacitors?
     
  18. woolenmammoth

    woolenmammoth Senior Member

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    how some of you guys have turned this into such a conspiracy is really hard to understand. You need some kind of double blind study to clip alligator leads to a pot and listen? It either sounds different or it doesnt, this aint rocket science. Probably %80 if not more of the stuff you clip in is gonna sound the same, every once and a while you find something that stands out. No painter is doing a double blind test to find the shade of paint they need, they sort through what they got until they find something that works and they move on...

    For the amount of time and effort it takes to actually listen and conclude for yourself its shocking there is so much bickering over nothing.
     
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  19. David Collins

    David Collins Senior Member

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    I can't speak for others, but I never saw any kind of conspiracy (ie, intentional manipulation and misleading of others for personal gain). I simply see an issue relative to my profession that seemed to be lacking sufficient evidence to base sound conclusions on.

    When customers call on me for advise on what they can do to affect their instruments in a particular way, I feel it is part of my job as a trusted luthier to do whatever is within my ability to ensure my advice is sound. If someone wants to change their tone a bit this way or that, and a change in capacitor type will predictably and reliably affect that change, I want to know. If the changes come by placebo effect, relying on their belief that it is improved rather than any true electrical phenomenon, then I would like to know as well. I don't actively sell components so I really don't care which side is evidenced to be true, I just feel obligated as a professional to be as best informed as possible so that I can provide reliable advice to my clients.

    Since I did not find suitable prior testing that I felt could hold water, and I hade the resources (and and at least a basic understanding of psychoacoustics and acceptable testing methods), I undertook this as a pet project in my limited spare time, and will make the results freely available for anyone to revue, accept, contest, or offer reasonable critique and peer revue.

    I don't see looking for honest and reliable evidence as a bad thing for a professional who is relied upon by clients to be honest and knowledgable in their field, or even for an enthusiast who just wants to know the truth.
     
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  20. Stinky Kitty

    Stinky Kitty Senior Member

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    This has actually been one of the more civil discussions of this topic. The archives are brimming with many such threads that so devolved into personal slugfests that moderator intervention occurred more than once.

    I believe that David's test methodology has the potential come close to having some actual value in the debate of cap type. And hope that we'll have the test in a manner that, by his own words, allows the caps the best chance of influencing tone by setting the tone pot at zero.

    It'll then be interesting to see how those samples map on freefrog's graphs.
     

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