Capacitor Conspiracy Theory

Discussion in 'Tonefreaks' started by imitebelvis, Dec 29, 2011.

  1. StandingWave

    StandingWave Senior Member

    Messages:
    4,079
    Likes Received:
    3,429
    Joined:
    Oct 24, 2011
    This is another way that vendors exploit the ignorant. My mechanic wanted to charge me $96 to rotate my spark plugs! I said, "Do you think I'm some kind of idiot? I wouldn't pay more than $40 for that!"
     
    2 people like this.
  2. spitfire

    spitfire Senior Member

    Messages:
    1,551
    Likes Received:
    1,573
    Joined:
    Sep 21, 2009
    Captain,

    Yes I do see what you are saying, and I agree that is a distinct possibility. Which is why I originally said that a tonal change would be the more obvious effect.

    Perception is one of the big problems with these types of discussions. As David Collins put it in his excellent post (#10), the brain is a tricky thing. And what we hear is not necessarily the actual sound.
     
  3. cooljuk

    cooljuk Transducer Producer Premium Member MLP Vendor

    Messages:
    13,342
    Likes Received:
    15,838
    Joined:
    Mar 12, 2009
    Same thing happened to me. My mechanic tried to tell me I needed my tires rotated. Ha! I'm no sucker. I know damn well they rotate every time I drive the car.
     
    3 people like this.
  4. cooljuk

    cooljuk Transducer Producer Premium Member MLP Vendor

    Messages:
    13,342
    Likes Received:
    15,838
    Joined:
    Mar 12, 2009
    It's pretty well accepted in audio engineering circles that, given two otherwise identical sources, the brain will favor one that is slightly louder or has slightly more higher frequencies. ...to an extent, of course.
     
  5. StandingWave

    StandingWave Senior Member

    Messages:
    4,079
    Likes Received:
    3,429
    Joined:
    Oct 24, 2011
    It makes sense to me that a tonal change could be perceived as a volume change.

    Perception (including lack thereof) presents tricky issues and makes blind audio testing problematic. One could argue that 'actual sound' is a construct of the brain, an interpretation of external stimuli. You can measure the stimuli, but everybody's processing is going to vary somewhat. Additionally, everybody is physically different -- our 'microphones' are not the same, even if/when working perfectly.
     
    2 people like this.
  6. spitfire

    spitfire Senior Member

    Messages:
    1,551
    Likes Received:
    1,573
    Joined:
    Sep 21, 2009
    I don't think there is any disputing that what we hear, or any other experience, is always an interpretation of reality.

    But, if the goal of a test is to differentiate between differences in sound (the real physical sound) from the differences in our interpretation, a blind test is exactly what you want. Give the subject the ability to do whatever they want, choose the guitar, amp, time of day etc. Anything reasonably related to playing the guitar. I.E., they don't get to use an x-ray machine to try to look at the cap.

    The only requirement is that they do not have any knowledge of the capacitor being used beyond what they can gather by playing and listening. If they can repeatedly detect differences to a statistically significant degree, and the test was run correctly, this would prove there is an audible difference.
     
    1 person likes this.
  7. imitebelvis

    imitebelvis Senior Member

    Messages:
    119
    Likes Received:
    76
    Joined:
    Dec 15, 2011
    wow this post is still going!

    this weekend i am rewiring my goldtop 50s style and testing some different caps i just picked up.

    i will install all the wiring and use alligator clips to switch out the caps for a quick change over.

    i could not get any POI, but i have orange drops, mallory 150s, ceramic disc and even some cheap greenies from radio shack.

    i'll let you know what my results are. no right or wrong, just what i think sounded better.

    setup will be my Epi goldtop, kent armstrong P90s, 500K+ audio taper pots through the clean channel of my peavey classic 30.
     
  8. J_Edgar

    J_Edgar Senior Member

    Messages:
    352
    Likes Received:
    286
    Joined:
    Dec 4, 2011
    Nice, enjoy your testing.

    But bear in mind that the difference in tone between running a cap soldered into the wiring harness and running a cap on flying leads and croc clips may be greater than the difference in tone between the caps. ;)
     
  9. StandingWave

    StandingWave Senior Member

    Messages:
    4,079
    Likes Received:
    3,429
    Joined:
    Oct 24, 2011
    I think I'd prefer a fresh thread on top-wrapping to any discussion of blind testing. I wouldn't ever stand in the way of your getting that experience though, and I'd be interested in a report on the methodology and the results.
     
  10. garybaldy

    garybaldy Senior Member

    Messages:
    1,582
    Likes Received:
    700
    Joined:
    Apr 10, 2011
    Better still,get your buddies to say which they prefer only dont tell em up front which is which heh heh:naughty:
     
  11. freefrog

    freefrog Senior Member

    Messages:
    1,185
    Likes Received:
    628
    Joined:
    May 21, 2011
    I will simply state the most honestly possible my own experience:

    Being a passionate guitar tweaker for more than 30 years, I pass my time to test and modify guitar gear for me and my friends (so they have a free guitar tech LOL). I "measure" empirically various specs (resonant frequencies, THD etc.) on guitar pickups for 8 years, each time I can do it. I also stock the related data: resistance, inductance, type of magnets and so on.

    The first time I've mounted vintage PIO's on a guitar (without changing anything else), I've noticed a change of the overall tone: although the cap value was higher than the capacitance of the previous caps, the signal was actually clearer to my ears... even when the controls full up.

    Eager to understand what happened, I've took my low impedance exciter coil and I have put it on my PU's like I had done dozens of times, and in exactly the same conditions: same signal sent to the exciter, same settings for the calibrated soundcard used, same cable to plug the guitar...

    Believe it or not: the screen has shown a noticeable change in the Q factor of my pickups (!).

    Experimental artifact? Maybe. But the screen and my ears were agreeing.

    It's after that weird experience that I've decided to dig this question of caps. I've started to do empirical experiments like those stated above in this topic.

    I don't know exactly what happens and if my testing gear creates artifacts. I’ll just say that…

    1)My measurements match what I hear. When I feed a PU with a continuous 1khz signal and when I look the harmonics of the PU, for example, the relative height of these harmonics is consistently different according to the cap used. Same thing with the THD, as shown above in this topic on my screenshot.

    2)The explanations above sum up my actual experience. I’ve nothing to sell. I’ve no “faith” to defend. I don’t claim to own any esoteric hidden knowledge. I just state what I’ve actually done and seen, in order to share it with the online community.

    Footnote: I’m not at all a tech head initially (I’ve a PhD related to human sciences). But one of my brothers is engineer in electronics and he helps me when I need it. I’ve talked more than once of these experiments with him. Although he's extremely prudent, he wasn't surprised by my results.

    Here is what I’ve (mis)understood during our discussions, roughly: caps aren't "ideal" devices. They haven’t only capacitance but also many other specs (their dielectric constant varies, etc.). They are incidentally inductive, resistive and… resonant components whose specs and behaviour vary according to external parms and factors (frequencies, etc.).

    2d footnote: I’m pretty sure that the “resonance” parm described by Claritycaps explains something. What I “hear” personally in PIO’s is something like the effect of a micro reverb tank. Suggestively, the caps that I find tonally different are most of the time things with different sizes and voltage rating (obviously, a PIO tube or an Orange Drop 715P haven’t the same size than a cheap ceramic disk).

    3d footnote: please, keep in mind that English is not my mother tongue. I struggle somehow to translate precisely some thoughts – Although this answer has been wrote with the only desire to clarify my statements and to be useful.
     
    1 person likes this.
  12. spitfire

    spitfire Senior Member

    Messages:
    1,551
    Likes Received:
    1,573
    Joined:
    Sep 21, 2009
    Would you be willing to provide your raw data? I would be interested in having a close look at it.


    For the sizes of capacitors we are talking about, the effects of parasitic inductance don't apply. While this is a real aspect of all capacitors, the inductance is quite small and only significant at frequencies very much higher than audio frequencies.

    The resistance really isn't an issue. The tone control pot itself is a massive resistance compared to any possible series resistance of the cap. The reverse is true for any shunt resistance. It's simply too high to matter in this circuit.

    This mechanical resonance, brought up earlier in this thread, is a new one on me. It sounds plausible. And while it might be real, it might very well be pseudo-science.

    There is force on the plates of a capacitor, because the electrical charges on the capacitor plates attract each other.

    Where there is force, there may be some mechanical deformation, however slight. Since capacitor electrical behavior is, in part, determined by it's physical construction, if this physical relationship changed, I would expect an electrical change.

    I did some rough calculations and I think the mechanical forces are on the order a few 100's of uN (10's of mg of weight). So this is a very small force, but it is not so small that it could be dismissed out of hand. Neither is it so large as to make it a given that it has any significance.
     
  13. Bristol Posse

    Bristol Posse Senior Member

    Messages:
    2,230
    Likes Received:
    2,845
    Joined:
    Jul 26, 2010
    The other problem with all of this aside from the cap science is that even if you could completely remove expectation bias from the test (ie I just spent a bunch of money on this cap, lots of people love this cap, people I respect tell me this cap is better....at some level I want this cap to be better than the one it is replacing so I will unconsciously listen through rose tinted earmuffs :shock:) you are still dealing with at least three other big problems (expectation bias can effect blind or double blind testing too. If you present the test as "tell me which one sounds better to you", even if you play the same sound three times you will get a preference stated for one test sound over the others, most of the time, because you have set up the test subject to expect one to be better and they will manufacture a preference because of that). any way on to the problems I see:

    1) consistency: subtle audible tone changes (assuming they are present at all) will really need to come out over a performance. for THD variances to be so large as to be instantly noticeable on a 1khz test tone there would basically have to be something wrong with the components (and what happens if there is no THD effect at a pure 1khz but a subtle effect at the various octave of a 382hz fundamental?) . Instead, you need notes across the the entire spectrum of the guitar, various volume/tone settings, clean and distorted. This requires a performance rather than a test tone and unless you can build a robot to do it you'll never get the same performance, touch, nuances etc two times

    2) Memory: When any of us say this sounds better than that we are comparing how we remember a sound to be versus something we are actually hearing. Even without expectation bias skewing the result, memory is far from perfect and highly unreliable as a comparison tool against a tone we are actually hearing

    3) Acoustic space: Unless you are in an anechoic chamber, even moving your head a couple of millimeters will effect how the sound reaching your ears sounds. Move an inch to the left you are in a 120hz null and the sound has less of that frequency, move to the right and wow listen to those lows, so much better for example. Now add to that that you lean forward toward the speaker for one listen and lean back away from the speaker for the next and even with the same amp settings, the sound reaching your ears in the first will be a couple of dB louder and while it is not very perceptible as louder, your brain will interpret the sound as "better" or more pleasing. On top of all this there is all the effect of on/off axis and the directionality of higher frequencies versus lower frequencies to consider and how your movement can effect this.
    If you want to hear this in action put on some music and walk around the room while really listening. In some spots the bass will be more present in others it will fade out. In other spots the hi hats will be much more noticeable and so on

    All of this will effect both blind, double blind and completely unscientific tests.

    so based on all of this I have changed this wiring and caps in my guitars because

    1) in my Epi the wiring was horrible and unreliable, in my Gibby was a PCB which just seems wrong to me (i like real wiring, I know what to do if it goes wrong).
    2) Tinkering with my guitar makes me happy and to quote the late Douglass Adams "I'd far rather be happy than right any day"

    As always YMMV
     
  14. spitfire

    spitfire Senior Member

    Messages:
    1,551
    Likes Received:
    1,573
    Joined:
    Sep 21, 2009
    I agree, all of these variables you mention would certainly be a concern if the goal of the test is to classify them in some way (good, better. best). Or even perhaps less subjective and classify them with values like brighter, and such.

    But, if the goal is to determine that there is a difference at all, you would want the user to try all manner of setups, clean, dirty etc. The idea is for them to exhaust all possibilities to give them the best chance of actually hearing a difference.

    This would at least prove the positive, that different cap types make a real physical difference that can be heard. After that, it would be a very different test to rate the capacitors.
     
  15. David Collins

    David Collins Senior Member

    Messages:
    1,066
    Likes Received:
    792
    Joined:
    Dec 20, 2009
    All good points, which I've tried my best to account for in surveys I've done. Most importantly is that I've never surveyed for preference (better or worse), but only a difference.

    My tests have basically been modeled after this one - [ame=http://www.youtube.com/watch?v=FClGhto1vIg]Sesame Street - One of these things - Circles - YouTube[/ame]

    The issue of consistency is a tough one, and though there are a number of ways to ensure a perfectly consistent signal, I do think that real human playing can still be the a near ideal test bed for this issue, just so long as reasonable efforts for maintaining controls are made.

    Still, the situation I'm trying to appraise here is this - loads of people on these forums share stories where even after the long time lapse and position shifting while swapping a cap, when they pick their guitar back up they are absolutely certain that they can hear a distinct difference. A change of qualities described using words like brittle, harsh, bright, sparkle, more highs, clarity, woody, warm, creamy, scooped mids, etc, all heard with absolute certainty in a comparison after an extended pause and repositioning.

    If all those distinct changes are caused by some electrical phenomenon involving the capacitor, then surely they should be able to identify "which of these things is not like the other" when the caps are switched in real time while the player is playing. Yes, there will inevitably be some slight change in the player's picking each time they play the same riff consecutively as the caps are switched. Those changes would inevitably be even more significant though if they have to put the guitar down, swap out caps, pick it back up and start playing again - yet they have no problem hearing the change with full certainty there.

    No survey or test will ever be perfect or satisfy everyone, yet I feel quite comfortable with this summary - If a change in cap type had an effect near as significant as many users report, or even a minor one which was clear enough to identify after a pause, then someone should be able to identify the odd one out in a multiple choice test switched in real time. Maybe I'll find someone who can some day, but I just haven't yet.
     
  16. garybaldy

    garybaldy Senior Member

    Messages:
    1,582
    Likes Received:
    700
    Joined:
    Apr 10, 2011
    I'm currently a PIO virgin but not for much longer.I have a 0.022 and a 0.015
    on their way to me in the UK from JONESY.
    This is a mind blowing thread and I am sort of of the opinion that its all in the way you play that creates what we hear but I would really like these caps to make a favourable difference.If they dont,could it be the way I play cos I cant get the best out of them?If they do,is it my imagination cos ive spent a bit of dosh (even though its relatively little)?
    I hope they do and its real.
     
  17. dem00n

    dem00n Senior Member

    Messages:
    1,465
    Likes Received:
    1,161
    Joined:
    Sep 10, 2009
    You guys need to join some death metal bands, talk to some death metal guitarists about caps...see where that goes. :laugh2::laugh2:
     
    1 person likes this.
  18. David Collins

    David Collins Senior Member

    Messages:
    1,066
    Likes Received:
    792
    Joined:
    Dec 20, 2009
    Just to make this thread even more weird, here's a little secret. In spite of not finding any difference directly caused by the caps, I like decently cool caps in my tone controls too. :D

    You don't have to expect tonal improvements from every part of your guitar in order to justify liking them. For a few bucks in the big scheme of things, why the hell not? In the end if I take pride in every little detail, whether aesthetic, directly functional, or never even seen nor heard, I find I can tend to carry that pride with me as much when playing it as when tinkering with it.

    In a professional capacity I feel I should know how and why things work as well as possible. I would never actually discourage people from getting "premium" parts (whatever that may really mean) if they're in to it. If they're on the fence and asking whether it will really have much effect, I'll share my experience and understanding of it honestly. If they've decided they really just want all the premium parts though, I'm absolutely fine with that. Nothing wrong with that at all.
     
    3 people like this.
  19. korus

    korus Senior Member

    Messages:
    994
    Likes Received:
    301
    Joined:
    Apr 10, 2007
    Some 2 years ago my band has been recording some songs. While remixing one of them, producer and I could not agree on one insignificant tiny detail - during a chorus he wanted one of the 3 guitar parts louder and I wanted it quieter. So we have a producer (P) and a guitarist (G). Here's the dialog:

    P: This is a non-isue. You want that guitar part what - 0.5 db lower?! It makes no sense to even discuss that as no one can hear the difference. There are drums, bass, 2 other guitars, lead vocal and 2 backing vocals doing their stuff all the time through this 20 sec segment, and this is the chorus, everything’s loud ... Man, no one can hear that 0.5 db difference in the 3rd guitar part, no one.

    G: I agree, ALMOST no one can hear the difference. But, I can and I want it quieter for those 0.5 db.

    P: No, you can not hear that, even Eric Johnson can not hear that, but I will lower it since it is that important to you.

    G: No actually it is not THAT important at all, but now we have a different issue to resolve. Instead of you telling me what I can and what I can not hear or me telling you what I can hear and what you can not tell me - we will do a rather simple test. This is how we'll do it. You will record both mix options first - (a) guitar louder (b) guitar quieter. Then I will turn around and look through the window while you, drummer and bassist/singer make a playlist out of these 2 mixes with total of 5 in the list - you’ll use the mix with louder guitar 3 times and the one with quieter guitar you will use 2 times, without me knowing which is the order you've put them in the playlist. You will play all 5 of them to me in sequence and I will tell you which 2 out of the 5 were those with the quieter guitar part. That chorus segment lasts some 20 sec so in a few minutes we all here will know what I can and what I can not hear.

    We record both mixes. I turn around and they make a playlist. Then he plays it. As it finishes he has a grin on his face and I have a grin on my face.

    P: Here’s the moment of truth. Tell us …

    G: You are a funny character. You've tried to cheat. You actually put the segment with quieter guitar part in the playlist only ONCE, not twice as we agreed. And it was the last one in the playlist, only 5th mix played had quieter guitar part.

    P : This is impossible. We'll do this again ...

    We did it actually 2 times more, the second test was with 6 segments (2 were quieter) in the playlist and the third and the last one was with 7 segments in the playlist (5 were quieter). Both times I did not know how many times he would use quieter guitar mix in the playlist, but it did not matter - I've answered correctly both in the second and in the third test. He gave up after the third test. He was in disbelief, thought that I've cheated somehow - but he apologized to me in the end.

    And what happened to that guitar part? We’ve just let it out of the mix eventually, as it was quite obsolete there.

    ( Even if off-topic, some might find this entertaining ... )
     
    4 people like this.
  20. freefrog

    freefrog Senior Member

    Messages:
    1,185
    Likes Received:
    628
    Joined:
    May 21, 2011
    I've sent you a PM about this request. To the whole community, I'll just say that I'm a mere human being who has to deal with the same limits than everybody: lack of free time due to a daily job, irony of life and events, and so on. Thx for your understanding and patience.


    I understand that it shouldn't make any difference. Simply, IME of player, the massive resistance of a pot is not a rock wall.
    An interesting test about it is to go back and forth between a regular tone pot with a regular cap and the same tone pot + a kind of Q filter/ Torres mid control (IOW: a 1H inductor in series with a cap in // with a small resistor). Even with the tone full up, the difference is there (the Q filter adds sparkle).


    I've not the power to decide if it's serious or not. I just know that this idea of resonance cooperates well with my feelings and thoughts of empirical hobbyist.
     

Share This Page