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DIY Stompboxes => Building your own stompbox => Topic started by: musiclikscreams on July 27, 2013, 02:22:34 AM

Title: Paper in oil caps
Post by: musiclikscreams on July 27, 2013, 02:22:34 AM
Been away from DIY stompboxin for about a year or so now and I'm lookin to start back up with an Em Drive clone (tagboardeffects.blogspot.com/2013/01/emerson-custom-guitars-em-drive.html)

I'm just having trouble finding PIO caps. Any help would be tremendously appreciated
Title: Re: Paper in oil caps
Post by: SmoothAction on July 27, 2013, 02:27:24 AM
Studiozey.com ...  ;)
Title: Re: Paper in oil caps
Post by: FiveseveN on July 27, 2013, 07:44:29 AM
It'll work and sound just as boutiquey with regular caps, you know.
Title: Re: Paper in oil caps
Post by: psychedelicfish on July 27, 2013, 08:21:02 AM
^but you won't get all that mojo noise...
Title: Re: Paper in oil caps
Post by: Fender3D on July 27, 2013, 09:30:11 AM
Here, in Italy I can provide gallons of pure extra virgin olive oil for cheap...
now if you only bring the paper...







 :icon_mrgreen:
Title: Re: Paper in oil caps
Post by: midwayfair on July 27, 2013, 10:26:34 AM
It'll work and sound just as boutiquey with regular caps, you know.

As long as boutiquey means crappy, which is what the Em Drive sounds like.
Title: Re: Paper in oil caps
Post by: Gus on July 27, 2013, 10:40:43 AM
I would build that simpe circuit with other caps to hear if you like it.

I looked at the tagboard site and noted the circuit is simple two caps 2 resistors and a transistor.  That type biasing can be troublesome.

Look at the following screenshot of a sim note how the collector voltage changes with different hfe transistors and bias/feedback collector to base resistor values I even have a emitter resitor that helps the em has a grounded emitter.

(http://www.aronnelson.com/gallery/main.php?g2_view=core.DownloadItem&g2_itemId=46374&g2_serialNumber=2)
Title: Re: Paper in oil caps
Post by: musiclikscreams on July 27, 2013, 10:49:54 AM
so PIO isn't really gonna make a huge difference in tone?  i wanted to build an em drive because i need a transparent drive in my chain and its mega simple.  i have a tendency to start big project and get burned out and never finish em. 

any alternative suggestions?  i got a bunch of vero layin round waiting to be used
Title: Re: Paper in oil caps
Post by: Jdansti on July 27, 2013, 11:26:14 AM
It'll work and sound just as boutiquey with regular caps, you know.

As long as boutiquey means crappy, which is what the Em Drive sounds like.

What do you recommend for a simple-ish drive that sounds decent?
Title: Re: Re: Re: Paper in oil caps
Post by: pappasmurfsharem on July 27, 2013, 11:32:30 AM
It'll work and sound just as boutiquey with regular caps, you know.

As long as boutiquey means crappy, which is what the Em Drive sounds like.

What do you recommend for a simple-ish drive that sounds decent?

The EM drive is fine for about 50% of the knobs travel after that it distorts like garbage.
Title: Re: Paper in oil caps
Post by: Gus on July 27, 2013, 11:58:04 AM
It'll work and sound just as boutiquey with regular caps, you know.

As long as boutiquey means crappy, which is what the Em Drive sounds like.

What do you recommend for a simple-ish drive that sounds decent?

The EM drive is fine for about 50% of the knobs travel after that it distorts like garbage.

If it sounds bad at 50%, one fix would be to use a 100k series resistor into the base with a  100K linear potentiometer this is about 1/2 of 250k
Title: Re: Paper in oil caps
Post by: smallbearelec on July 27, 2013, 01:02:46 PM
Build an Ursa Minor:

https://www.smallbearelec.com/Projects/UrsaMinor/UrsaMinor.htm

My PC board for it:

http://www.smallbearelec.com/servlet/Detail?no=1391

is less than $8.00. Leave the diode loop open and it is an adjustable clean boost.
Title: Re: Paper in oil caps
Post by: R.G. on July 27, 2013, 01:19:29 PM
But meanwhile, back at paper-in-oil caps.

I lucked into an old book entitled "Power Capacitors", which contained a history of capacitors used for power applications. It described the manufacture and materials and why those changed over time.

When electricity was just getting started as an industry, they needed caps for AC power line work, telegraphs, etc. They knew from the early experimenters that metal foils separated by an insulator worked, ala Leyden jars.

Glass was expensive, so they tried paper, which worked OK, and would normally withstand the voltage, except for two things. Paper absorbs moisture from the air, which lowers its withstanding voltage, and it contains particles which conduct, and voids. Depending on the paper's manufacture, the conductive particle probability per unit area could be reduced, but not eliminated. So they figured out that is so many square feet of paper had X probability of a conductive particle, then sandwiching two layers would mean that there was essentially no possibility that two conductive particles would line up. That meant that they could make capacitors from two layers of paper and metal foils. But the paper still absorbed moisture.

Someone figured out that they could fill the voids in the paper with insulating oil, and then moisture could not get in. This had the extra advantage of boosting the withstanding voltage and of increasing the capacitance because of the increased dielectric constant of the oil. And bango! Paper-in-oil capacitors were born. Strictly speaking, they are oil filled caps, the paper being mostly something to mechanically prop the metal foils from touching and the oil providing the dielectric constant and moisture immunity.

There were still issues. The paper was twice as thick as it needed to be, which made the capacitors big and heavy. So they waited around til polypropylene film was invented, and started using that instead of one layer of paper. This worked well, the paper still held the oil, and the polypro kept conductive particles from killing the cap. Eventually, when polypro film got better, they realized they didn't need the paper any more, and that the caps could be made smaller and cheaper with just the plastic film, so the film-in-oil capacitor was born. Even later, with better metal foils and films, they realized that the oil could be dispensed with, which was good since there were those nasty poly-chlorinated-biphenyls in the really good insulating oils.

From there it was thinner films and foils, different stacking, etc. to get modern film caps.
Title: Re: Paper in oil caps
Post by: Phorhas on July 27, 2013, 02:00:18 PM
Yes, all that science jive is nice - but what about tone ?!

PIO caps make me sound way better - equivalent to an extra 20 seconds of practice each day !

 ;)
Title: Re: Paper in oil caps
Post by: adstrum on July 27, 2013, 03:04:41 PM
The EM drive clone is pretty unimpressive. It would seem a waste put drop some expensive PIO caps into it. Those caps can add a nice touch to a great pedal, but it's not a magic panacea for ordinary sounding boards.
Title: Re: Paper in oil caps
Post by: Jdansti on July 27, 2013, 03:35:06 PM
Yes, all that science jive is nice - but what about tone ?!

PIO caps make me sound way better - equivalent to an extra 20 seconds of practice each day !

 ;)

Wow!  Think of how great you'd sound by practicing an extra whole minute every day! ;)
Title: Re: Paper in oil caps
Post by: musiclikscreams on July 27, 2013, 05:29:16 PM
The EM drive clone is pretty unimpressive. It would seem a waste put drop some expensive PIO caps into it. Those caps can add a nice touch to a great pedal, but it's not a magic panacea for ordinary sounding boards.

Thank you, I was looking for a straight forward answer. Thanks for all the input guys. I think I'll slap one together with just plain ol caps and see how it sounds
Title: Re: Paper in oil caps
Post by: tca on July 27, 2013, 06:12:26 PM
^ I've breadboard it with plain caps, it sounds as it should: good with a big boost.

Cheers.
Title: Re: Paper in oil caps
Post by: midwayfair on July 27, 2013, 06:40:55 PM
any alternative suggestions?  i got a bunch of vero layin round waiting to be used

Do you just need boost, or do you also need dirt from the pedal?

-The beginner project here is dead simple and nevertheless impressive sounding.
-Smallbear's Ursa Major that Steve linked to will have far, far better distortion than the Em Drive with only a couple extra parts.
-AMZ's Mosfet Booster or Micro Booster are both excellent transparent boosts (if you don't need more dirt). I also love the Madbean Fatpants.
-Shameless plug: the "Clipper Ship" project on my web site has gotten some good marks from a couple people I trust. It's a little more complicated than the other three but will do just boost or just dirt as well. (And there's a PCB for it.)
-Not that I condone such things, but there are layouts for certain legendary "transparent overdrives" that only use a single dual op amp and have good bass and treble controls. The parts count is also really low on that one.
Title: Re: Paper in oil caps
Post by: psychedelicfish on July 27, 2013, 08:11:34 PM
^ The AMZ MOSFET boost with its gain on full has some decent sounding dirt to it
Title: Re: Paper in oil caps
Post by: musiclikscreams on July 27, 2013, 08:57:02 PM
any alternative suggestions?  i got a bunch of vero layin round waiting to be used

Do you just need boost, or do you also need dirt from the pedal?

-The beginner project here is dead simple and nevertheless impressive sounding.
-Smallbear's Ursa Major that Steve linked to will have far, far better distortion than the Em Drive with only a couple extra parts.
-AMZ's Mosfet Booster or Micro Booster are both excellent transparent boosts (if you don't need more dirt). I also love the Madbean Fatpants.
-Shameless plug: the "Clipper Ship" project on my web site has gotten some good marks from a couple people I trust. It's a little more complicated than the other three but will do just boost or just dirt as well. (And there's a PCB for it.)
-Not that I condone such things, but there are layouts for certain legendary "transparent overdrives" that only use a single dual op amp and have good bass and treble controls. The parts count is also really low on that one.

ya i wanted a low part count transparent overdrive pedal.  kind of a first stage drive... something i can leave on that gives a little dirt.  something with a smooth break up.
'
now i've been outa the diy scene for quite a while now... can u clue me in a little more on these "legendary 'transparent overdrives'" you speak of?  transparent is what i'm going for and, well, legendary... i'm always down for some of that
Title: Re: Paper in oil caps
Post by: musiclikscreams on July 27, 2013, 09:02:17 PM
btw... i wanted to thank you guys for all the help.  i've been around here on and off for the past 5 years and i can't remember dealing with any attitudes... just a bunch of helpful fellow DIYers
Title: Re: Paper in oil caps
Post by: Jdansti on July 28, 2013, 12:18:00 AM
>ya i wanted a low part count transparent overdrive pedal.  kind of a first stage drive... something i can leave on that gives a little dirt.  something with a smooth break up.

If you're feeling tooby, there's the Valvecaster. Low parts count and easy to build.

Sample clip with neck pickup:
1) Clean-Bypassed
2) Gain= 0%
3) Gain= 50%
4) Gain= 75%
5) Gain= 100%
6) Clean-Bypassed

https://soundcloud.com/john-danna/valvecaster-clean-50-75-100/s-sg2cn

Beavis Audio Valvecaster: http://www.beavisaudio.com/projects/ValveCaster/

Forum: http://www.diystompboxes.com/smfforum/index.php?topic=63479.0 (Happy reading! ;))

Title: Re: Paper in oil caps
Post by: pappasmurfsharem on July 28, 2013, 12:56:20 AM
any alternative suggestions?  i got a bunch of vero layin round waiting to be used

Do you just need boost, or do you also need dirt from the pedal?

-The beginner project here is dead simple and nevertheless impressive sounding.
-Smallbear's Ursa Major that Steve linked to will have far, far better distortion than the Em Drive with only a couple extra parts.
-AMZ's Mosfet Booster or Micro Booster are both excellent transparent boosts (if you don't need more dirt). I also love the Madbean Fatpants.
-Shameless plug: the "Clipper Ship" project on my web site has gotten some good marks from a couple people I trust. It's a little more complicated than the other three but will do just boost or just dirt as well. (And there's a PCB for it.)
-Not that I condone such things, but there are layouts for certain legendary "transparent overdrives" that only use a single dual op amp and have good bass and treble controls. The parts count is also really low on that one.

ya i wanted a low part count transparent overdrive pedal.  kind of a first stage drive... something i can leave on that gives a little dirt.  something with a smooth break up.
'
now i've been outa the diy scene for quite a while now... can u clue me in a little more on these "legendary 'transparent overdrives'" you speak of?  transparent is what i'm going for and, well, legendary... i'm always down for some of that

Yes what is the legendary transparent overdrive you speak of?
Title: Re: Paper in oil caps
Post by: Phorhas on July 28, 2013, 02:51:18 AM
Yes, all that science jive is nice - but what about tone ?!

PIO caps make me sound way better - equivalent to an extra 20 seconds of practice each day !

 ;)

Wow!  Think of how great you'd sound by practicing an extra whole minute every day! ;)

You mean 5x the PIO caps !
Title: Re: Paper in oil caps
Post by: Jdansti on July 28, 2013, 02:54:15 PM
 ;D ;D ;D
Title: Re: Sv: Re: Paper in oil caps
Post by: Johan on July 28, 2013, 03:15:40 PM
Yes, all that science jive is nice - but what about tone ?!

PIO caps make me sound way better - equivalent to an extra 20 seconds of practice each day !

 ;)

Wow!  Think of how great you'd sound by practicing an extra whole minute every day! ;)

You mean 5x the PIO caps !
...i think it would take no more than 3 pio's to get him to the level of one minute...one pio=20sek, 1 minute=60sek..but how many pio's does it take to become a master?...1800000 if we are to believe another recent thread...j
Title: Re: Paper in oil caps
Post by: tca on July 29, 2013, 07:32:19 PM
You can get some good OD sounds out the Ursa Minor circuit:

(http://www.diale.org/img/mix.png)
Title: Re: Paper in oil caps
Post by: kingswayguitar on July 29, 2013, 08:26:22 PM
>ya i wanted a low part count transparent overdrive pedal.  kind of a first stage drive... something i can leave on that gives a little dirt.  something with a smooth break up.

If you're feeling tooby, there's the Valvecaster. Low parts count and easy to build.

Sample clip with neck pickup:
1) Clean-Bypassed
2) Gain= 0%
3) Gain= 50%
4) Gain= 75%
5) Gain= 100%
6) Clean-Bypassed

https://soundcloud.com/john-danna/valvecaster-clean-50-75-100/s-sg2cn

Beavis Audio Valvecaster: http://www.beavisaudio.com/projects/ValveCaster/

Forum: http://www.diystompboxes.com/smfforum/index.php?topic=63479.0 (Happy reading! ;))


sweet at 75%
Title: Re: Paper in oil caps
Post by: Jdansti on July 29, 2013, 10:07:33 PM
Thanks. I was recording direct, so I imagine it would sound much better driving a toob amp. :)
Title: Re: Paper in oil caps
Post by: Thecomedian on July 30, 2013, 12:43:27 AM
It'll work and sound just as boutiquey with regular caps, you know.

http://www.youtube.com/watch?feature=player_embedded&v=92G-jw4TqS4#at=601

material of guitar caps do have a sonic impact on sound, via how they pass the frequency ranges. I find PiO caps to be fuller in the mid-2nd harmonics coming from the low fundamentals being a little meatier with PiO, or is it the high frequencies die out slightly faster..
Title: Re: Paper in oil caps
Post by: Thecomedian on July 30, 2013, 12:57:40 AM
if current and wattage used are no object, I seem to get some good value taking the Orman Mini-booster, switching the fets to 2n3819, and taking the Rs and Cs feedback components off the bottom resistor and connecting the source of the 2n3819 on bottom direct to ground.

It has a very wide range of input voltage into a softer distortion/clip, but it costs 11mA instead if 0.9mA-6mA of current like the original mini-booster design.

any alternative suggestions?  i got a bunch of vero layin round waiting to be used

Do you just need boost, or do you also need dirt from the pedal?

-The beginner project here is dead simple and nevertheless impressive sounding.
-Smallbear's Ursa Major that Steve linked to will have far, far better distortion than the Em Drive with only a couple extra parts.
-AMZ's Mosfet Booster or Micro Booster are both excellent transparent boosts (if you don't need more dirt). I also love the Madbean Fatpants.
-Shameless plug: the "Clipper Ship" project on my web site has gotten some good marks from a couple people I trust. It's a little more complicated than the other three but will do just boost or just dirt as well. (And there's a PCB for it.)
-Not that I condone such things, but there are layouts for certain legendary "transparent overdrives" that only use a single dual op amp and have good bass and treble controls. The parts count is also really low on that one.

ya i wanted a low part count transparent overdrive pedal.  kind of a first stage drive... something i can leave on that gives a little dirt.  something with a smooth break up.
'
now i've been outa the diy scene for quite a while now... can u clue me in a little more on these "legendary 'transparent overdrives'" you speak of?  transparent is what i'm going for and, well, legendary... i'm always down for some of that

Yes what is the legendary transparent overdrive you speak of?

im piqued as to the term "transparent overdrive". Is it an electrical term meaning it doesn't modulate the signal in any other form than distorting/clipping, as in no frequency losses or gains? I've made something similar to that in a Spice file somewhere..
Title: Re: Paper in oil caps
Post by: FiveseveN on July 30, 2013, 08:36:36 AM
http://www.youtube.com/watch?feature=player_embedded&v=92G-jw4TqS4#at=601

Come on, there's a 34-page thread about the issue on the other forum and from all the capsniffers' arguments you decide to pick the least scientific "test" out there?! Make an effort, man!

Quote
frequency ranges
Caps don't understand "frequency", they only know about "impedance".

Quote
I find PiO caps to be fuller in the mid-2nd harmonics
Are you basing this on what you think you hear or some measurement? How do they know how to distinguish 2nd harmonics from fundamentals? Do your caps have DSP? Or is it ESP?
Title: Re: Paper in oil caps
Post by: midwayfair on July 30, 2013, 10:06:01 AM
Quote

Yes what is the legendary transparent overdrive you speak of?

im piqued as to the term "transparent overdrive". Is it an electrical term meaning it doesn't modulate the signal in any other form than distorting/clipping, as in no frequency losses or gains? I've made something similar to that in a Spice file somewhere..

Go look up the term on TGP if you want to know what pedal I'm talking about. I'm not going to post about it and encourage someone to clone it. Let's just say it's a pretty famous pedal and the designer builds them himself and charges an extremely fair price for them.
Title: Re: Paper in oil caps
Post by: Thecomedian on July 30, 2013, 11:11:39 PM
http://www.youtube.com/watch?feature=player_embedded&v=92G-jw4TqS4#at=601

Come on, there's a 34-page thread about the issue on the other forum and from all the capsniffers' arguments you decide to pick the least scientific "test" out there?! Make an effort, man!

Quote
frequency ranges
Caps don't understand "frequency", they only know about "impedance".

Quote
I find PiO caps to be fuller in the mid-2nd harmonics
Are you basing this on what you think you hear or some measurement? How do they know how to distinguish 2nd harmonics from fundamentals? Do your caps have DSP? Or is it ESP?

your snark not withstanding, you can capture images and verify the frequency specific behaviors of the caps side by side. Caps aren't intelligent objects. No, they don't understand frequency. Yes, they work on impedance. Yes impedance is Frequency dependent. Yes, caps do work on frequencies. Yes, hysteresis exists. Im basing it on what I think I hear, and then comparing what I think Im hearing to his live frequency charts.

Quote

Yes what is the legendary transparent overdrive you speak of?

im piqued as to the term "transparent overdrive". Is it an electrical term meaning it doesn't modulate the signal in any other form than distorting/clipping, as in no frequency losses or gains? I've made something similar to that in a Spice file somewhere..

Go look up the term on TGP if you want to know what pedal I'm talking about. I'm not going to post about it and encourage someone to clone it. Let's just say it's a pretty famous pedal and the designer builds them himself and charges an extremely fair price for them.

Im not sure what TGP is.
Title: Re: Paper in oil caps
Post by: FiveseveN on July 31, 2013, 12:35:06 AM
you can capture images and verify the frequency specific behaviors of the caps side by side.
Sure you can, but that is not the way to do it. Where the "test" goes wrong:
1. Variations in playing, which accounts for most of the error and completely nullifies the point of the experiment.
2. Constructive tolerances and drift. You can see the actual measured values of the caps in part 3 (http://www.youtube.com/watch?v=S7Hod21pIUI).
3. The Bode plot is a joke. Not enough resolution or peak hold time (which is hard to read anyway).
4. The signal suffers further filtering and distortion (from the ampsim, though it's a "clean" model, from the speaker and mic) which obfuscates the caps' influence.
Of course 2, 3 and 4 become irrelevant because of 1.
Also you can't compare 7 sounds by just stringing 3 second samples one after the other. By the time you've heard the third you would have forgotten the first.

So yes, caps, like any other parts, have nonlinearities and parasitics, and they can and are measured (see a datasheet/app note/white paper). We can also devise rigurous tests to determine if these effects have an audible impact in a certain application. Sadly no such rigurous tests actually exist, probably because nobody takes capsniffers seriously.
Title: Re: Paper in oil caps
Post by: psychedelicfish on July 31, 2013, 12:39:36 AM
you can capture images and verify the frequency specific behaviors of the caps side by side.
Sure you can, but that is not the way to do it. Where the "test" goes wrong:
1. Variations in playing, which accounts for most of the error and completely nullifies the point of the experiment.
Surely if you were testing frequency specific behaviours of various caps you'd be using a sine wave generator, thus eliminating variations in playing?
Title: Re: Paper in oil caps
Post by: Thecomedian on July 31, 2013, 12:49:24 AM
On the other hand, you're thoroughly convinced, on complete lack of any evidence, that caps DONT cause audio differences, when you're saying that no such rigorous test exists to either prove or disprove it. Maybe you didn't watch or listen at the point where he had visual simulation of signal strength for bands of frequency. Those aren't bode plots. I'm more inclined to believe at least some evidence rather than believe in the opposite case when there is no evidence proving or disproving the opposite case. Your position is an argumentum ad ignorantiam, wrapped up in question begging.
Title: Re: Paper in oil caps
Post by: Thecomedian on July 31, 2013, 01:00:21 AM
you can capture images and verify the frequency specific behaviors of the caps side by side.
Sure you can, but that is not the way to do it. Where the "test" goes wrong:
1. Variations in playing, which accounts for most of the error and completely nullifies the point of the experiment.
Surely if you were testing frequency specific behaviours of various caps you'd be using a sine wave generator, thus eliminating variations in playing?

Quote
We can also devise rigurous tests to determine if these effects have an audible impact in a certain application. Sadly no such rigurous tests actually exist, probably because nobody takes capsniffers seriously.

Even if you proved that various caps have differences, such as the hysteresis tests done by some people, it's still not enough evidence for him because it doesn't prove beyond a shadow of a doubt that such differences are sonically noticeable by human ears. Anyone who hears differences in sound is obviously delusional, despite the fact that tone deafness is a real thing which exists, in the form of neurological disorders or brain damage, or lack of training and fine tuning.

http://health.howstuffworks.com/human-body/systems/ear/tone-deaf1.htm

If we suppose that he is personally crusading against the idea of caps making a sonic difference, because he cannot hear difference himself, we could conclude that he is tone deaf and committing an argument from incredulity. Again, there is no evidence to support his claims or condemn the claims of proponents of cap "mojo" types, however, there is evidence that cap material and even the voltage rating has an effect on the way it modifies the signal.

It's unthinkable to consider that caps have such huge effects on frequencies of a signal due to the mere capacitance factor, and yet have absolutely no effect, not even minimal effects, due to all the other small differences in caps. It's like Boolean logic: if it's not 1, it must be 0. We don't live in a digital world.
Title: Re: Paper in oil caps
Post by: Gus on July 31, 2013, 06:27:11 AM
So yes, caps, like any other parts, have nonlinearities and parasitics, and they can and are measured (see a datasheet/app note/white paper). We can also devise rigurous tests to determine if these effects have an audible impact in a certain application. Sadly no such rigurous tests actually exist, probably because nobody takes capsniffers seriously.

http://www.scribd.com/doc/2610442/Capacitor-Sound (http://www.scribd.com/doc/2610442/Capacitor-Sound)

Title: Re: Paper in oil caps
Post by: amptramp on July 31, 2013, 10:19:50 AM
If you are talking about testing capacitors for distortion, there is a simple test for dielectric absorption:

1. Charge a capacitor to a fixed voltage value.
2. Short out the capacitor.
3. Remove the short.
4. Measure capacitor voltage.

This test can be done at uninstrumented measurement speeds.  You can do it with a battery, a piece of wire and a voltmeter.

What happens intenally is that the dielectric material is polarized so its molecules line up in the direction of the applied field.  When it is shorted, the voltage disappears, but there is no mechanism to restore the dielectric molecules to a random position and they naturally tend to stay oriented positive to negative.  When the short is lifted and the voltage is measured, you get the effect of polarized molecules lined up.  This is an effect similar to an electret, the permanent electrostat device that corresponds to a permanent magnet.  Electrets are commonly used in microphones and capacitors that use similar dielectrics may be microphonic.

I am not aware of any other distortion mechanism which is as important.  Obviously, if dielectric molecules line up under an applied field, the capacitance will be larger because of the proximity of the positive side of one molecule with the negative side of another.  This may explain why some capacitors sound good if they are coupling a plate to a grid with a consistent high voltage between them, but may add distortion at an input or a tone control stage where there is little DC bias across the terminals.  With a liquid dielectric like paper in oil, the randomizing effect of fluid flow may trump the electrostatic effect as long as the temperature of the capacitor is high enough. 
Title: Re: Paper in oil caps
Post by: induction on July 31, 2013, 11:46:47 AM
If we suppose that he is personally crusading against the idea of caps making a sonic difference, because he cannot hear difference himself, we could conclude that he is tone deaf and committing an argument from incredulity.

That's not what 'tone deaf' means. This part of your argument would be classified as an appeal to ridicule.

Quote
there is evidence that cap material and even the voltage rating has an effect on the way it modifies the signal.

Empirical signal analysis tests are not very convincing to me.  The question isn't whether differences exist, it's whether they are audible.  The only way to examine this is tightly controlled double-blind listening tests.  If you can find someone who can consistently tell which cap is which in such tests, you prove your academic point that the differences are, in principle, detectable.

Then you move on to the real-world scenario: are the differences audible in a musical context?  Another set of double-blind listening/playing tests. 

How many caps in the signal chain does it take to tell the difference?  More tests. If you test enough people and enough scenarios, you'll end up with a distribution of cap detection abilities of the given population. People on the upper end of the spectrum (assuming anyone passes the tests) get to spend more money on components.

I suspect that the differences, if they exist, are so small that they are overwhelmed in influence by the rest of the signal chain/air temperature/humidity/etc, and that the first experiment will make the rest unnecessary.  But I haven't actually done the controlled experiments, so I could be wrong.

The likelihood that anyone in the audience cares is certainly much lower.  Whether or not that's important is more of a personal thing.
Title: Re: Paper in oil caps
Post by: FiveseveN on July 31, 2013, 12:56:33 PM
http://www.scribd.com/doc/2610442/Capacitor-Sound (http://www.scribd.com/doc/2610442/Capacitor-Sound)
Yes, that's exactly what I said: distortion can be measured. But...

The question isn't whether differences exist, it's whether they are audible.
Bingo! Everyone can see that even in the worst-performing example in the article, the highest-amplitude distortion product is 65 dB down, right? So it's not Scribd messing with me or my apparent overwhelming bias against the golden-eared. Yes, some people claim to be able to hear 100 ppm of distortion. Some people claim to have been kidnapped by aliens. Want to guess which group is more numerous?

My skepticism on the matter is rooted in our growing knowledge about the immense gap between what we percieve and what we imagine, what our brain assumes in order to save resources.
Title: Re: Paper in oil caps
Post by: Bill Mountain on July 31, 2013, 01:02:29 PM
I'm not a cap apologist but there is something special about big fat orange drops in a Fender-ish amp.

Why not put some big "mojo" components in a pedal if it makes you feel good?
Title: Re: Paper in oil caps
Post by: FiveseveN on July 31, 2013, 01:15:18 PM
Hey, that's a completely different story. I've hoarded a bunch of "mojo" parts myself, because, you know, they're quirky and pretty.
If it makes you or your customers feel better, I say go right ahead, as long as you're not disingenuous.
Title: Re: Paper in oil caps
Post by: wavley on July 31, 2013, 01:30:04 PM
I'm not a cap apologist but there is something special about big fat orange drops in a Fender-ish amp.

Why not put some big "mojo" components in a pedal if it makes you feel good?

I can't tell you how many silverface fenders I've pulled the poo brown caps out and replaced with orange drops for a remarkable improvement.  To paraphrase Morrissey "Some caps are better than others, yes some caps are better than others.  Some cap's mothers are better than other cap's mothers"  The poo brown caps have always sounded worse, so it's not a new cap vs. old cap thing. It lifts the final veil off of the upper mid range in my audiophool voice ::)  But seriously, it does make a difference.  I just fixed a friend's 62 Vibrolux which is pretty magic.  I had it and my somewhere around 69 or 70 dead stock one sitting right next to it and slowly in stages I brownfaced mine.  I started with supply caps, tested, coupling caps, tested (it made a great but not earth shattering difference), and then started making all the circuit changes one by one and testing.  I haven't gotten to the trem mod yet because I have to order  a pot, but I have certainly gotten it close enough that I consider my amp (which I thought was decent sounding before) to be pretty magic.  Was it scientific?  Not exactly, but I did take pretty good care to understand everything that was changing.

There is a point where mojo gets out of hand and I really would like to see some science to back it up though.  I don't really begrudge somebody some mojo unless it turns into some real cork sniffing elitism and blanket statements, because so often it's about application.  Isn't it R.G. that proved if you used old brown resistors over 100 volts that it actually does create desirable harmonic content, although it may be negligible?  So 9 volts=noise 150 volts=magic?  Is this true of caps too?

Particularly in a dirt box I have my doubts about the extra fidelity of a certain kinds of caps running at low voltage, although I don't care for regular disc ceramics in just about anything, but anything other than orange discs might just be mojo when it comes to low voltage dirt.

If the mojo makes you feel better, then cool, it's your rig.  Let's just realize that sometimes it's just mojo and don't rationalize it so much.


Title: Re: Paper in oil caps
Post by: Bill Mountain on July 31, 2013, 02:29:00 PM
I'm not a cap apologist but there is something special about big fat orange drops in a Fender-ish amp.

Why not put some big "mojo" components in a pedal if it makes you feel good?

I can't tell you how many silverface fenders I've pulled the poo brown caps out and replaced with orange drops for a remarkable improvement.  To paraphrase Morrissey "Some caps are better than others, yes some caps are better than others.  Some cap's mothers are better than other cap's mothers"  The poo brown caps have always sounded worse, so it's not a new cap vs. old cap thing. It lifts the final veil off of the upper mid range in my audiophool voice ::)  But seriously, it does make a difference.  I just fixed a friend's 62 Vibrolux which is pretty magic.  I had it and my somewhere around 69 or 70 dead stock one sitting right next to it and slowly in stages I brownfaced mine.  I started with supply caps, tested, coupling caps, tested (it made a great but not earth shattering difference), and then started making all the circuit changes one by one and testing.  I haven't gotten to the trem mod yet because I have to order  a pot, but I have certainly gotten it close enough that I consider my amp (which I thought was decent sounding before) to be pretty magic.  Was it scientific?  Not exactly, but I did take pretty good care to understand everything that was changing.

There is a point where mojo gets out of hand and I really would like to see some science to back it up though.  I don't really begrudge somebody some mojo unless it turns into some real cork sniffing elitism and blanket statements, because so often it's about application.  Isn't it R.G. that proved if you used old brown resistors over 100 volts that it actually does create desirable harmonic content, although it may be negligible?  So 9 volts=noise 150 volts=magic?  Is this true of caps too?

Particularly in a dirt box I have my doubts about the extra fidelity of a certain kinds of caps running at low voltage, although I don't care for regular disc ceramics in just about anything, but anything other than orange discs might just be mojo when it comes to low voltage dirt.

If the mojo makes you feel better, then cool, it's your rig.  Let's just realize that sometimes it's just mojo and don't rationalize it so much.




I agree with everything you've said.  I don't have a rational reason for disliking the ceramics that I use for breadboarding (but never build with).  But how can we claim that science proves one type of part is not better than others but then say this part is better than this part.  What would you or anyone say to someone who said brown caps in a Fender sound just as good???

I hate mojo (and most ad copy for that matter) but the attitude we have about proving without a shadow of a doubt why something should be done as certain way is the reason why some people get driven off of this board.  It's also the reason I'm afraid to show all of my experiments because I know I can't back up why I did something a certain way and why it's better than other ways of doing it.  None of this is against you personally.  Your post just provided me a segue to get some things off of my chest.

As the internet matures I see more and more scientific pissing contests on almost all the forums I visit.
Title: Re: Paper in oil caps
Post by: R.G. on July 31, 2013, 02:43:20 PM
You want *good* caps?

Go to a welding supply store and buy some of the 2" x 4?" glass plates used for the front of a welder's helmet. Then to the metal-foil supply store for some tin (not aluminum) foil, thin as you can get it.

Supplies in hand, begin stacking. Lay down a plate of glass. Then a rectangle of foil, with 1/8" to 1/4" spacing on three edges of the glass, and lapping outside the glass on the fourth side. Then a plate of glass, and another foil, but this time the section outside the glass is on the opposite side of the stack from the foil just below it. Repeat. Do as many layers as you want capacitance. The capacitance is pretty easily calculable from junior-physics parallel plate equations. When you have enough, solder the foils on each side (hence the tin, not aluminum) of the stack. Put on a top glass for passivation, bind the stack and passivate/glue it with something like varnish or epoxy on all sides.

This makes a very, very high quality, linear capacitor with quite a high voltage rating.

It's just big, heavy, and fragile.  :)
Title: Re: Paper in oil caps
Post by: bluebunny on July 31, 2013, 03:28:34 PM
^^^ Let's see Jon Patton squeeze *that* into one of his 1590A builds!  :D
Title: Re: Paper in oil caps
Post by: wavley on July 31, 2013, 03:35:52 PM
First of all, let me say that my use of the word magic to describe amps was meant to describe how great they sound.  After sitting down with two amps, two schematics, comparing, and changing components and circuits one by one in order to analyze that part of the circuit's contribution to the sound.  Yeah, it sounds magic now, but I absolutely know how I got there.  Of course it wasn't perfectly controlled, I wasn't going to sit down and record a riff and then play it back so that the nuances of my playing didn't influence the sound or anything, it's pretty absurd to do that just for myself.  I took an amp that sounded pretty blah and made it sound great, while comparing it to a known great sounding amp.

Second, please nobody take it as an attack on any of them.  Honestly, I dig mojo components (although I personally refrain from calling them that) if I have them around and I feel they'll do a good job in the circuit, or I just want it to look cool just for me.  I don't dig disc caps because on a bunch of occasions I've found them to be little microphones, I prefer not to invite that into my circuits because after all in the quantities in which I build the cost for a component that I know isn't going to be a little microphone is worth it to me.

I will on occasion ask for some sort of science to back something up that makes me roll my eyes, and sometimes that science backs up what the person was saying and it's great, you've convinced me.

What would I say to someone that like the sound of brown caps in a Fender?  Well, what folks think sound good is totally subjective for one, I like 13-56 flatwound strings on a Jaguar, not really what a lot of other folks consider great tone.  So it really depends on how condescending they were when they said it as to what my response would be.  BUT, in MY experience, and all of the techs I used to work with at the shop, poo brown caps sound worse than the older blue ones or orange drops, but honestly the real night and day differences between the brown, black, and silver fenders are the circuits... there is a pretty big difference in sound between using the 12ax7 phase inverter of a brown fender and the 12at7 of the black and silver.  They have different PI values, different tone stacks, and different negative feedback and when you combine all of those things it made the amp sound magic to my ears.  When I was a kid I and rode BMX I had a friend that was always concerned with shaving an ounce or two off his bike here and there, when I asked him why he said "One ounce here, two ounces there, pretty soon you get up to a pound or two.  A pound or two can be the difference between winning and loosing the race."  So yes, I will take the caps I think sound a little better as part of the equation

And Bill, I actually thought I was backing your last post up up, I didn't mean to offend you and I'm not the most eloquent person so it may be my fault. The fact that I work in radio astronomy R&D, I tend to be required to back my findings up with science at work the IEEE fellow I work for tends to like that kind of stuff so sometimes the skeptic in me wants to see some science.  At home... not so much, but I still tend to use the same methods.  I'm no RG or PRR, and wouldn't pretend to be, I'm certainly not going to attack anybody for not completely understanding a circuit, if it sounds good then it sounds good... awesome.
Title: Re: Paper in oil caps
Post by: Bill Mountain on July 31, 2013, 03:43:02 PM

And Bill, I actually thought I was backing your last post up up, I didn't mean to offend you

You were backing me up and you didn't offend me.

I should not have quoted you.  It was just some stream of conscience typing.

I enjoyed your post very much.  It just made me evaluate myself.  I crave the scientific backing for my reasoning but I also have a soft spot for certain types of components.  I was just trying to point out that I find it difficult to judge anyone when I'm not in control of my own feelings.  I was trying to have an open discourse so I provided an alternate viewpoint.

No one should feel the need to defend themselves to me.  For that I am sorry.
Title: Re: Paper in oil caps
Post by: wavley on July 31, 2013, 03:53:51 PM

And Bill, I actually thought I was backing your last post up up, I didn't mean to offend you

You were backing me up and you didn't offend me.

I should not have quoted you.  It was just some stream of conscience typing.

I enjoyed your post very much.  It just made me evaluate myself.  I crave the scientific backing for my reasoning but I also have a soft spot for certain types of components.  I was just trying to point out that I find it difficult to judge anyone when I'm not in control of my own feelings.  I was trying to have an open discourse so I provided an alternate viewpoint.

No one should feel the need to defend themselves to me.  For that I am sorry.

It's cool, I like me some spirited discourse about electronics.

Honestly, most of my emotional response was to R.G.'s new signature "Magic: any technology you do not understand", which I felt was a dig on why I felt my amp sounded like magic and that I didn't understand how it got there.  Which it may or may not have actually been, so I probably shouldn't get emotional so quick.  So here's a preemptive "Sorry R.G."

[edit] RG, I realize that you may have taken offense to the example of the resistors.  I was trying to make a point that sometimes there is science to back up "mojo" in certain applications, but the mojo doesn't work in the wrong application.
Title: Re: Paper in oil caps
Post by: defaced on July 31, 2013, 04:27:30 PM
Quote
R.G.

Magic: any technology you do not understand
I just noticed this.  I just finished a project where I had to take pre weld and post weld distortion evaluations of the test I was welding.  I set up two tables, before and after, on the same sheet of paper and separated them by a big white area with text in the middle that reads "Magic Happens".  I know no one will ever ask for that piece of paper, but if anyone ever reads it besides me, I hope they see the humor in it. 

Humor aside, I'm on a quest for the least expensive, legitimately sourced (no eBay BS) coupling caps I can find.  Currently Epcos are winning out with the B32529 series caps (which Mouser stocks many values of, thankfully).  In a very unscientific way I am going to see if I notice any deleterious effects of these vs the 225P Sprague caps I use now (literally the least and most expensive 400v 0.022u cap stocked on Mouser right now, $1.43 vs $0.18). 
Title: Re: Paper in oil caps
Post by: wavley on August 01, 2013, 11:53:52 AM
Quote
R.G.

Magic: any technology you do not understand
I just noticed this.  I just finished a project where I had to take pre weld and post weld distortion evaluations of the test I was welding.  I set up two tables, before and after, on the same sheet of paper and separated them by a big white area with text in the middle that reads "Magic Happens".  I know no one will ever ask for that piece of paper, but if anyone ever reads it besides me, I hope they see the humor in it. 

Humor aside, I'm on a quest for the least expensive, legitimately sourced (no eBay BS) coupling caps I can find.  Currently Epcos are winning out with the B32529 series caps (which Mouser stocks many values of, thankfully).  In a very unscientific way I am going to see if I notice any deleterious effects of these vs the 225P Sprague caps I use now (literally the least and most expensive 400v 0.022u cap stocked on Mouser right now, $1.43 vs $0.18). 

Cap technology has come so far in the last 20 or so years that I bet the difference between a "good" cap and a "bad" cap today is much less than those of yesteryear.
Title: Re: Paper in oil caps
Post by: tubegeek on August 01, 2013, 07:32:03 PM
"And all this science, I don't understand
It's just my job five days a week
A rocket man, a rocket man

And I think it's gonna be a long, long time ‘til touchdown brings me round again to find I'm not the man they think I am at home
Oh no, no, no, I'm a rocket man
Rocket man, burning out his fuse up here alone."

-Bernie Taupin
Title: Re: Paper in oil caps
Post by: wavley on August 02, 2013, 10:24:53 AM
You want *good* caps?

Go to a welding supply store and buy some of the 2" x 4?" glass plates used for the front of a welder's helmet. Then to the metal-foil supply store for some tin (not aluminum) foil, thin as you can get it.

Supplies in hand, begin stacking. Lay down a plate of glass. Then a rectangle of foil, with 1/8" to 1/4" spacing on three edges of the glass, and lapping outside the glass on the fourth side. Then a plate of glass, and another foil, but this time the section outside the glass is on the opposite side of the stack from the foil just below it. Repeat. Do as many layers as you want capacitance. The capacitance is pretty easily calculable from junior-physics parallel plate equations. When you have enough, solder the foils on each side (hence the tin, not aluminum) of the stack. Put on a top glass for passivation, bind the stack and passivate/glue it with something like varnish or epoxy on all sides.

This makes a very, very high quality, linear capacitor with quite a high voltage rating.

It's just big, heavy, and fragile.  :)

You mean a little like this?
(http://fbcdn-sphotos-a-a.akamaihd.net/hphotos-ak-frc3/972105_10201182426658844_1375154623_n.jpg)

When we need a "good" coupling cap in the femtofarads for GHz work we use custom made parallel plate caps, of course we use quartz instead of glass and the plates have bondable gold.  These particular ones are 25x6x3 mils.

Excuse the blurry pic through a microscope using my cell camera.
Title: Re: Paper in oil caps
Post by: R.G. on August 02, 2013, 10:48:06 AM
Honestly, most of my emotional response was to R.G.'s new signature "Magic: any technology you do not understand", which I felt was a dig on why I felt my amp sounded like magic and that I didn't understand how it got there.  Which it may or may not have actually been, so I probably shouldn't get emotional so quick.  So here's a preemptive "Sorry R.G."

[edit] RG, I realize that you may have taken offense to the example of the resistors.  I was trying to make a point that sometimes there is science to back up "mojo" in certain applications, but the mojo doesn't work in the wrong application.
No apology necessary. I'm mildly amazed at this. I was not following this thread to any significant extent. I had not read your comment about your amp sounding like magic. And yes, I can see where you might have a response to that, justifiably so if I was being snippy.

So, I'm sorry for the unintended slight - it really was an accidental confluence. I knew nothing your post at the time I put that up. 

The quip had its roots in the saying that "Any sufficiently advanced technology is indistinguishable from magic." and the derivative "Any technology distinguishable from magic is insufficiently advanced."

I was profoundly affected by reading the question about what would happen if a true scientific genius from the 1800s was examining and trying to understand and operate a nuclear power reactor. The technology base to avoid a disaster is simply not there - and he would have undoubtedly have believed that the reactor was indistinguishable from magic.
Title: Re: Paper in oil caps
Post by: davent on August 02, 2013, 11:52:48 AM
You'll need something bigger then an "A" for a few of these PIO's. http://www.partsconnexion.com/DUELUND-74523.html
Title: Re: Paper in oil caps
Post by: induction on August 02, 2013, 12:55:46 PM
You'll need something bigger then an "A" for a few of these PIO's. http://www.partsconnexion.com/DUELUND-74523.html

And maybe a mortgage.
Title: Re: Paper in oil caps
Post by: Bill Mountain on August 02, 2013, 01:16:11 PM
You'll need something bigger then an "A" for a few of these PIO's. http://www.partsconnexion.com/DUELUND-74523.html

I like how the MSRP and the sale price are the same.
Title: Re: Paper in oil caps
Post by: davent on August 02, 2013, 01:17:51 PM
You'll need something bigger then an "A" for a few of these PIO's. http://www.partsconnexion.com/DUELUND-74523.html

And maybe a mortgage.

I'm sure it can be arranged but you need to move fast as they show only ten in stock! Other mojorific values available.
Title: Re: Paper in oil caps
Post by: musiclikscreams on August 03, 2013, 11:10:52 AM
Wow this got a lot more attention that I realized. I got a bunch of components off eBay and once they get here Ill let you know how it turns out
Title: Re: Paper in oil caps
Post by: Thecomedian on August 05, 2013, 01:18:26 AM
If we suppose that he is personally crusading against the idea of caps making a sonic difference, because he cannot hear difference himself, we could conclude that he is tone deaf and committing an argument from incredulity.

That's not what 'tone deaf' means. This part of your argument would be classified as an appeal to ridicule.

Quote
there is evidence that cap material and even the voltage rating has an effect on the way it modifies the signal.

Empirical signal analysis tests are not very convincing to me.  The question isn't whether differences exist, it's whether they are audible.  The only way to examine this is tightly controlled double-blind listening tests.  If you can find someone who can consistently tell which cap is which in such tests, you prove your academic point that the differences are, in principle, detectable.

Then you move on to the real-world scenario: are the differences audible in a musical context?  Another set of double-blind listening/playing tests.  

How many caps in the signal chain does it take to tell the difference?  More tests. If you test enough people and enough scenarios, you'll end up with a distribution of cap detection abilities of the given population. People on the upper end of the spectrum (assuming anyone passes the tests) get to spend more money on components.

I suspect that the differences, if they exist, are so small that they are overwhelmed in influence by the rest of the signal chain/air temperature/humidity/etc, and that the first experiment will make the rest unnecessary.  But I haven't actually done the controlled experiments, so I could be wrong.

The likelihood that anyone in the audience cares is certainly much lower.  Whether or not that's important is more of a personal thing.

Uh, pretty sure "tone deaf" would mean he wouldn't be able to consciously recognize sonic differences. You'd be surprised how far a person can "fine tune" their brain to hear the most subtle differences. That's why they tell you to expose your baby to music and words from an early age, because it develops those processes that are important in understanding things which rely on "air vibrations". Pretty clear.

Additionally, you're arguing for his own tired point. Go ahead and check out the simple test in the members only page of a contest on hearing the difference between a klon pedal and some other pedal. Someone in there got the pedals 100% correct, someone else got them 100% accurately tracked, but inverted their choice of which were the klons and which were the other pedal. Both indicate that people CAN actually hear such subtle differences.

It is my personal experience, that most music was mostly listening to the melody section of music, and the notes and subtleties coming from the harmony and rhythm sections were not recognizable consciously to myself, until I actually spent time practicing "listening" to pick out the individual instruments.

Tone deaf people can't be taken seriously when they ignore logic. Can you hear bats squeaking outside your window at night using their echolocation? I can. Maybe if you say you can't bats are clearly "mojo" devices and anyone who believes they can hear something you can't is an alien abductee or something, because they must be the crazy one, not you.
Title: Re: Paper in oil caps
Post by: induction on August 05, 2013, 01:41:48 AM
Tone deaf means 'unable to recognize differences in musical pitch.' Not relevant here.

As for Joe Gore's experiment, the fact that people can recognize the difference between two different pedals in no way indicates that anyone can hear the difference between different types of the same value of capacitor.

Again, I'm not saying that it's impossible, just that it hasn't been demonstrated, and I'm skeptical. You'd be surprised how far a person can "fine tune" their brain to hear the most subtle differences that aren't actually there, if they expect those differences to exist. Lot's of people on this forum and others can transcribe music just by listening to it, and can very easily separate all of the instruments, but can't hear the difference between different types of the same value of capacitors.
Title: Re: Paper in oil caps
Post by: mistahead on August 05, 2013, 01:55:55 AM
Tone deaf means 'unable to recognize differences in musical pitch.' Not relevant here.

As for Joe Gore's experiment, the fact that people can recognize the difference between two different pedals in no way indicates that anyone can hear the difference between different types of the same value of capacitor.

Again, I'm not saying that it's impossible, just that it hasn't been demonstrated, and I'm skeptical. You'd be surprised how far a person can "fine tune" their brain to hear the most subtle differences that aren't actually there, if they expect those differences to exist. Lot's of people on this forum and others can transcribe music just by listening to it, and can very easily separate all of the instruments, but can't hear the difference between different types of the same value of capacitors.

Gotta step into it a little methinks...

Can you accept that in applications PIO will operate or function differently to another type of cap? (There is plenty of solid data from enthus's and manufacturer's to support that this is the case.)

Can you accept that in small audio circuits there are too few parts (and too little "active" band) for a "faulty" part to hide? (Subjective - needs to be answered to bother with discussion at all.)

There is logic behind... well logic - take away enough of the good sense and you end up with a bunch of subjective crap - we know the operation of the parts is different, we know that circuits we use can be "coloured" by parts in key positions, so pure logic tells us we could be in that range where the parts are affecting "tone" audibly...

Wait... Are you suggesting that the conversation is reaching a point where people are saying if I threw a "black box" TS clone to a "trained listener" they could tell me by listening to it (isolated into their rig) which MATERIALS C1-CX were made from? I think one of us is taking the wrong amount away here... not EXACTLY the right amount out of the same words.

Edit: missed a key word, cleaned up the formatting.
Title: Re: Paper in oil caps
Post by: induction on August 05, 2013, 11:03:24 AM
Gotta step into it a little methinks...

Can you accept that in applications PIO will operate or function differently to another type of cap? (There is plenty of solid data from enthus's and manufacturer's to support that this is the case.)

I do not accept that the method of their operation is fundamentally different.  They do roughly the same thing (store charge separation in two conductors separated by an insulator) with different materials. I do accept that the different materials may have different response functions that are measurable by an oscilloscope. In all cases that I've seen, these differences were detected in connection with voltages, frequencies, and/or intensities that made them irrelevant to stompbox operation. I accept that they could, in principle, be detected by ear. I am skeptical that they are detectable by ear.

Quote
Can you accept that in small audio circuits there are too few parts (and too little "active" band) for a "faulty" part to hide? (Subjective - needs to be answered to bother with discussion at all.)

Yes. We are not talking about faulty parts. We are talking about different types of caps with the same value.

Quote
There is logic behind... well logic - take away enough of the good sense and you end up with a bunch of subjective crap - we know the operation of the parts is different, we know that circuits we use can be "coloured" by parts in key positions, so pure logic tells us we could be in that range where the parts are affecting "tone" audibly...

We know that circuits can be colored by different values in key positions. Whether 9V circuits can be audibly colored by using the same value but different materials is the claim that I am skeptical about. Pure logic does not tell us that differences between caps seen in an oscilloscope that fall outside of the range of operation of the part and circuit in question can cause an audible difference in a pedal.

Quote
Wait... Are you suggesting that the conversation is reaching a point where people are saying if I threw a "black box" TS clone to a "trained listener" they could tell me by listening to it (isolated into their rig) which MATERIALS C1-CX were made from? I think one of us is taking the wrong amount away here... not EXACTLY the right amount out of the same words.

I am not suggesting any such thing. I'm not sure what you're talking about here.

I'll say it again because I believe I've been misinterpreted: I am not claiming that it is categorically impossible for people to hear differences between different types of caps with identical values in certain circuits. I am saying that I have seen no evidence for this except for self-reports under uncontrolled circumstances, so I am skeptical. The only way this can be demonstrated conclusively is tightly controlled, double-blind listening/playing tests.

Insults ("tone deaf", "tired point", "neurological disorders or brain damage, or lack of training and fine tuning") are not logic, and are not persuasive.

Analogies ('I can hear bats' (so can I), 'I can hear instruments even when they aren't playing a melody', 'some people can tell the difference between a Klon and a tubescreamer') are not persuasive.

Straw men ("anyone who believes they can hear something you can't is an alien abductee or something, because they must be the crazy one, not you",  "Anyone who hears differences in sound is obviously delusional") are not persuasive.

Controlled, double-blind tests are persuasive.
Title: Re: Paper in oil caps
Post by: midwayfair on August 05, 2013, 11:27:51 AM
Additionally, you're arguing for his own tired point. Go ahead and check out the simple test in the members only page of a contest on hearing the difference between a klon pedal and some other pedal. Someone in there got the pedals 100% correct, someone else got them 100% accurately tracked, but inverted their choice of which were the klons and which were the other pedal. Both indicate that people CAN actually hear such subtle differences.


While I don't have the data or the inclination to jump in on the cap side of this argument, I do need to point out that an isolated case of a single individual getting the answers to Joe's quiz correct is a poor choice to support your argument. This is not useful data because we can't rule out chance. You would need to test the same individual multiple times in a double blind test with multiple types of sound differences and against a control population. In a nutshell, this is the same issue with anecdotal evidence (minus the additional possibility of anecdotal evidence just being made up).

We do have overwhelming evidence that different people can hear different frequency spectra, because things like hearing loss exist. That's really it.

But here's the real barrier to testing "golden ears." You need to know a huge amount of data on the person before you can begin to test them at all: What's their total range of frequency? What role does experience and ear training play in their ability to perceive differences? What role does chance play? Are they experiencing any ear fatigue during the test? Are their sinuses acting up that day? Is psychoacoustics playing a role in their answers? How many times do you need to test them to get a baseline? How many times do you need to test a control group to get a baseline? It becomes very much like measuring pain. At some point you simply have to resign yourself to self-reporting on a purely subjective scale with few useful reference points.
Title: Re: Paper in oil caps
Post by: induction on August 05, 2013, 02:42:28 PM
But here's the real barrier to testing "golden ears." You need to know a huge amount of data on the person before you can begin to test them at all: What's their total range of frequency? What role does experience and ear training play in their ability to perceive differences? What role does chance play? Are they experiencing any ear fatigue during the test? Are their sinuses acting up that day? Is psychoacoustics playing a role in their answers? How many times do you need to test them to get a baseline? How many times do you need to test a control group to get a baseline? It becomes very much like measuring pain. At some point you simply have to resign yourself to self-reporting on a purely subjective scale with few useful reference points.

If the goal of the test is to demonstrate whether it is possible for someone to hear the difference, then you don't need to know all of this to get a positive result.  If any test subject can consistently identify the difference, the point has been made (assuming proper controls on the setup of the test and proper statistical analysis of the result).  If no one ever passes the test, it still won't be proven that it is impossible, but after enough test without a positive result you can generalize to 'even if the effect exists, it's too small to matter in any practical situation', and none of the above questions matter. If, on the other hand, you get even a few positive results, you can start to make rough estimates of the number of people in a population who can detect the difference. Then you can start to modify the tests to start examining your questions, and dig deeper into the details, if you were interested.

I'd settle for a single positive result.
Title: Re: Paper in oil caps
Post by: artifus on August 05, 2013, 03:04:02 PM
here is a guitar solo as played by mr. jimi hendrix:

*use your imagination*

here is a guitar solo as played by mr. jimmy page:

*use your imagination*

compare and contrast

*use your imagination*
Title: Re: Paper in oil caps
Post by: mistahead on August 05, 2013, 07:10:55 PM
Gotta step into it a little methinks...

Can you accept that in applications PIO will operate or function differently to another type of cap? (There is plenty of solid data from enthus's and manufacturer's to support that this is the case.)

I do not accept that the method of their operation is fundamentally different.  They do roughly the same thing (store charge separation in two conductors separated by an insulator) with different materials. I do accept that the different materials may have different response functions that are measurable by an oscilloscope. In all cases that I've seen, these differences were detected in connection with voltages, frequencies, and/or intensities that made them irrelevant to stompbox operation. I accept that they could, in principle, be detected by ear. I am skeptical that they are detectable by ear.

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Can you accept that in small audio circuits there are too few parts (and too little "active" band) for a "faulty" part to hide? (Subjective - needs to be answered to bother with discussion at all.)

Yes. We are not talking about faulty parts. We are talking about different types of caps with the same value.

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There is logic behind... well logic - take away enough of the good sense and you end up with a bunch of subjective crap - we know the operation of the parts is different, we know that circuits we use can be "coloured" by parts in key positions, so pure logic tells us we could be in that range where the parts are affecting "tone" audibly...

We know that circuits can be colored by different values in key positions. Whether 9V circuits can be audibly colored by using the same value but different materials is the claim that I am skeptical about. Pure logic does not tell us that differences between caps seen in an oscilloscope that fall outside of the range of operation of the part and circuit in question can cause an audible difference in a pedal.

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Wait... Are you suggesting that the conversation is reaching a point where people are saying if I threw a "black box" TS clone to a "trained listener" they could tell me by listening to it (isolated into their rig) which MATERIALS C1-CX were made from? I think one of us is taking the wrong amount away here... not EXACTLY the right amount out of the same words.

I am not suggesting any such thing. I'm not sure what you're talking about here.

I'll say it again because I believe I've been misinterpreted: I am not claiming that it is categorically impossible for people to hear differences between different types of caps with identical values in certain circuits. I am saying that I have seen no evidence for this except for self-reports under uncontrolled circumstances, so I am skeptical. The only way this can be demonstrated conclusively is tightly controlled, double-blind listening/playing tests.

Insults ("tone deaf", "tired point", "neurological disorders or brain damage, or lack of training and fine tuning") are not logic, and are not persuasive.

Analogies ('I can hear bats' (so can I), 'I can hear instruments even when they aren't playing a melody', 'some people can tell the difference between a Klon and a tubescreamer') are not persuasive.

Straw men ("anyone who believes they can hear something you can't is an alien abductee or something, because they must be the crazy one, not you",  "Anyone who hears differences in sound is obviously delusional") are not persuasive.

Controlled, double-blind tests are persuasive.


Just read through the above, I appreciate the tutorial in discussion at the end (makes me sure I'm speaking with someone who knows "The Rules" of discussion - game on), and the clarification of your point just prior to that - it seemed off however I was, resulted in an apparent strawman - sorry about that.  Additionally love the word "skeptical" up there and the good semantics being played, dubious outcomes will result... anyway back at the plot.

Regardless of what TYPE of component we are referring to. We can in fact shake out a couple of key points, by stepping through it.

1. Despite manufacturers statements, 'scopes, and other (generally accepted as reliable sources) stating that component behaviour could be (or is) different due to the way it operates you are "skeptical" that it could have an impact on the output sound of a circuit.

2. We can accept key components qualities (such as 'raw' component values) can influence the output sound of a circuit if used in key positions of many circuits, in fact we measure the "secondary" traits to select components for some applications (eg. leakage)

3. Controlled double blind tests are SUBJECTIVE and not persuasive - physics, maths and logic do not lie.

Without going all "MOJO PARTS MAKE ALL THE DIFFERENCE" on you, I don't value that sh*t either, I am happy to accept that the way a component is made an functions, can in fact impact on its operation when compared to another similar component that is made and functions differently. If this operational difference occurs in an portion of a circuit that has influence on the output sound of a circuit, and in a portion of the signal that is audible at output, why would it NOT impact on the sound?

Actually - just went back and re-read your post, don't bother responding to the above, semantics games are all we are going to get here. Kthxbai.

Title: Re: Paper in oil caps
Post by: Thecomedian on August 06, 2013, 12:24:55 AM
Additionally, you're arguing for his own tired point. Go ahead and check out the simple test in the members only page of a contest on hearing the difference between a klon pedal and some other pedal. Someone in there got the pedals 100% correct, someone else got them 100% accurately tracked, but inverted their choice of which were the klons and which were the other pedal. Both indicate that people CAN actually hear such subtle differences.


While I don't have the data or the inclination to jump in on the cap side of this argument, I do need to point out that an isolated case of a single individual getting the answers to Joe's quiz correct is a poor choice to support your argument. This is not useful data because we can't rule out chance. You would need to test the same individual multiple times in a double blind test with multiple types of sound differences and against a control population. In a nutshell, this is the same issue with anecdotal evidence (minus the additional possibility of anecdotal evidence just being made up).

We do have overwhelming evidence that different people can hear different frequency spectra, because things like hearing loss exist. That's really it.

But here's the real barrier to testing "golden ears." You need to know a huge amount of data on the person before you can begin to test them at all: What's their total range of frequency? What role does experience and ear training play in their ability to perceive differences? What role does chance play? Are they experiencing any ear fatigue during the test? Are their sinuses acting up that day? Is psychoacoustics playing a role in their answers? How many times do you need to test them to get a baseline? How many times do you need to test a control group to get a baseline? It becomes very much like measuring pain. At some point you simply have to resign yourself to self-reporting on a purely subjective scale with few useful reference points.

I agree about "small sample sizes", however, the point was that it's extremely telling that one person got the answers PERFECTLY 100% backwards, indicating that they could differentiate between the two, although they didn't know which was which. I could definitely tell one version was more "mid/low-mid".

Tone deaf means 'unable to recognize differences in musical pitch.' Not relevant here.

As for Joe Gore's experiment, the fact that people can recognize the difference between two different pedals in no way indicates that anyone can hear the difference between different types of the same value of capacitor.

Again, I'm not saying that it's impossible, just that it hasn't been demonstrated, and I'm skeptical. You'd be surprised how far a person can "fine tune" their brain to hear the most subtle differences that aren't actually there, if they expect those differences to exist. Lot's of people on this forum and others can transcribe music just by listening to it, and can very easily separate all of the instruments, but can't hear the difference between different types of the same value of capacitors.

While it's true people can be subject to priming and even auditory hallucinations, I tend to trust my ears when it comes to listening and picking out sounds which are clearly there. I can turn my head and hear the buzzing and high pitched whine that comes out of my LCD tv, provided the rest of the environment is quiet enough. You'd be surprised how annoying a laptop's AC adapter can be at night, when it's in sleep mode. It sets the block into a pulsing mode, so you can hear whenever it switches on and off, and I can verify that it was indeed coming from that block because at the same time it pulses, the LED/power indicator turns green and then turns off again. I remember the first time I heard it and had to dig around trying to figure out wtf was making that annoying noise. Now I just unplug my lappy before I sleep.


The point of the story is that under proper or improper settings, subtle differences can be masked or exaggerated, which definitely would account for some people not considering "different parts of the same farad values make a sonic difference".

As for tone deafness and it's relevance to the conversation:

http://en.wikipedia.org/wiki/Tone_deafness

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The ability to hear and reproduce relative pitch, as with other musical abilities, is present in all societies and in most humans. The hearing impairment appears to be genetically influenced, though it can also result from brain damage. Someone who is unable to reproduce pitches because of a lack of musical training would not be considered tone deaf in a medical sense. Tone deafness affects the ability to hear relative pitch changes produced by a musical instrument.

Suppose a cap DID affect a suble tonal difference? A medically tone deaf person, the same as a non-musically trained person, would both be unable to hear that.

A medically tone deaf person, even with medical training, would still be unable to hear subtle tonal differences.

let me ask you a simple question. Do you believe the mid/bass/treble boost/cuts implanted in a guitar actually make a tonal difference when playing with them? Or what about the pickup selection/blend?

When I first started playing I couldn't really hear any difference at all. I learned to hear the difference by messing around with it forever, and eventually fine tuning myself. Other non-trained people often say the same thing on youtube videos: They don't hear any perceptual difference between selecting neck or bridge pickup in a video. if we really want to get nuts with this conversation, we can say that since those people cant tell the difference, then even IF there is scope/oscillator/output evidence that there ARE changes to the signal, all of that data is meaningless, because it could all just be perception. This is the same logic as people who claim that, despite scope differences and clear variations with the same values of farad caps, there "isnt a statistically valid study to prove the "mojo parts" actually impart a sonic difference".

Maybe all the people who believe they hear a tonal difference when picking 100% neck or 100% body pickup are really all victim to a mass delusion, just like those people who hear sonic differences between caps of different manufacture/material/internal design, but same farad. I mean, both the cap differences and the tone knobs DO produce variations in the signal's output on scopes, but we could all just be "expecting" to hear that difference, and deluding ourselves into perceiving it even though it's not there, right?

I'm suggesting that this entire discussion is silly, because measuring instruments don't lie, but people are too individual to agree on something as "subjective" as audio sounds. Some people love the sound of one fuzz face over another. some people hate the fuzz face but love overdrive. Some people love dubstep and some people think it sounds awful. Isn't it possible that people crusading against "mojo parts" may not have the "ear"/dislike the tonal quality, and so deny any tonal variation exists?


Tone deafness can still be relevant to this discussion, btw.

http://jakemandell.com/tonedeaf/

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In our research, we were looking for neuro-anatomical correlates of tonedeafness (called "congenital amusia" in the scientific literature. The test you are about to take was used as a screening test to roughly characterize a patient’s pitch discrimination and musical memory abilities. Even though musical memory is strongly tested here, we have found that people who are tonedeaf tend to have normal musical memories.

That could be important for discerning subtle qualitative differences caps make.

There's a rule that if the cap is in the AC signal traffic, it's important, but anywhere else, such as DC only, it doesn't matter what it is, almost. We even put a 100uf and .01 uf caps on the DC power bus, because the different size of the farad (and material) will help cover the high and low frequencies of power introduced hum and interference into the AC signal.

http://www.npr.org/programs/atc/features/2002/jan/tonedeaf/020116.tonedeaf.html

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   Monica is a perfectly healthy middle-aged woman. She's normal in every way -- except that she's tone deaf. And as NPR's Joe Palca reports for All Things Considered, she's helping Canadian researchers discover why it is that some people can't carry a tune to save their life. They say genes might be the answer.


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At Peretz's lab in the University of Montreal, testing showed that Monica was off the bottom of the scale in her ability to recognize melodies. Peretz then tested Monica's ability to hear changes in pitch. She played her several sequences of five tones, with the fourth tone in each either rising or falling in pitch. In one of the sequences Monica listened to, most people -- even babies -- could detect the change, says Peretz. Monica couldn't.

Monica could detect some dramatic shifts, but sometimes even those weren't enough. And for some reason, she couldn't identify tone differences that were lower than the surrounding tones. 


Consider the following in light of the previous quote: There is very rarely any "black and white" "on or off" behavior in brains. THere are "degrees of expression". Some people may be "partially tone deaf", such as not having the ability to recognize tonal shifts if the surrounding tones are dB louder, as in the case of Monica. However, they may be able to recognize subtle shifts, even when mixed with other tones, if that tone is of equal or greater strength.

this starts to sound reasonably close to the concept that some people can record the frequency differences of caps of different design and identical farad, and other people can claim that the repeated differences could be due to "playing style" and "less rigorous scientific method", simply because they fail to hear the difference, and are convinced such difference can't exist.

If you'd asked me 1 year ago if such difference were possible, I would also have said no. I've seen discovered I can discern the difference between all neck or all bridge pickup selection, however, so I can't believe that the answer of different caps of identical farads causing tonal differences will be a definitive no.

http://www.sciencedaily.com/releases/2007/08/070823214755.htm

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 In a study comparing amusics to people with normal musical ability, researchers used a brain imaging and statistical technique to measure the density of the white matter (which consists of connecting nerve fibers) between the right frontal lobe, where higher thinking occurs, and the right temporal lobes, where basic processing of sound occurs. The white matter of the amusics was thinner, which suggests a weaker connection. Moreover, the worse the tone deafness, the thinner the white matter.


 Well, I guessed at the possibility of "tone deafness" being a continuum, and apparently the density of white matter correlates to "how tone deaf someone is".

http://www.theatlantic.com/health/archive/2013/05/tone-deafness-a-broken-brain/275470/

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It's been difficult for researchers to get over the idea that, with enough exposure to music, people born with amusia might somehow learn to listen. But even as music has become even more pervasive (think iPods), the condition persists. Last year, Peretz and her team looked into the potential to train young people with amusia, who they reasoned might have enough brain plasticity to be somewhat remediated. They gave 14 amusic 10- to 13-year-olds their basic test for music-hearing ability, then sent them home with MP3 players loaded with popular music (200 songs they found on the Internet, such as "No One" by Alicia Keys), which they were instructed to listen to for 30 minutes a day. Four weeks later, they were retested.

The kids tried. They ended up listening to their MP3 players for closer to 45 minutes a day. But at the end of the month, not only did they fail to improve on the tests, how poorly they scored correlated with how much music they reported listening to.

A new study published in the journal Brain takes it back a step by trying to figure out exactly where the brains of people with amusia go wrong. While subjecting participants to  a basic melody-recognition test, researchers in Lyon, France studied their brain activity using magnetoencephalography (MEG) scanners. They found that amusic people's difficulties on the test stemmed from delayed or otherwise impaired functioning of two areas of the brain, the frontal and auditory cortexes, during the early encoding of melodic information. What's more, the researchers detected physical abnormalities in those brain areas. For example, they had more grey matter and less white matter than is usual in the frontal cortex. This "convergence of functional and structural brain differences" appears to explain people with congential amusia's inability to both process pitch and retain short-term memory of melodies.


There's at least enough science out there to conclude that it's very likely that "the golden ear" is a real thing.
Title: Re: Paper in oil caps
Post by: gritz on August 06, 2013, 07:11:07 AM
"These capacitors are so special that only the most musical of listeners will be able to fully appreciate the richness of their sound, the tight bass, sparkling treble and clean transient response. Special offer, only $20 each while stocks last."

Would anyone admit (even to themselves) to having a tin ear after blowing a bunch of money on esoteric hardware? Or perhaps what the super-sensitive listener might be detecting is not "perfect" reproduction, but a flaw (albeit a not-unpleasant one)? Why else would so many audiophiles like valve amps?

Arguing about this kind of stuff is like discussing religion - everybody has their beliefs and they care not a jot for the opposing point of view. A lot of what is presented as "fact" (on both sides) is offered by people with a vested interest, or is harvested by way of confirmation bias. Let people make up their own minds (just so long as they don't drone on endlessly about it).

I guess what irks the "non believers" is that an awful lot of obvious BS is put out there by people who are either trying to sell something, or to appear smart / superior, or who wish to otherwise exploit the naivete of others. Of course there are also evangelists who actually believe what they are spouting, but that doesn't automatically make it true.

Suggestion for newbies: Focus your efforts on the nuts and bolts, like Ohm's law. Invest in the most blameless components, tools and test gear that you can reasonably afford - and be prepared to do plenty of research. Keep an open mind, but remember that there will be people who will try to pull the wool over your eyes, or who will accidently mislead you. It's a long road, but try to get the basics down. There will be plenty of time for the "paranormal" stuff later and you'll be in a better position to understand it, or at least to ask the right questions.

Magic is just science that we don't understand yet.
Title: Re: Paper in oil caps
Post by: Thecomedian on August 06, 2013, 08:12:18 AM
While that's true, the opposite effect must also be avoided, yes? The non believers professing their faith just as wildly, and with just as little (or LESS) evidence. I'm all against either side snake-oiling the masses.

We actually have some scientific backing to explain why the very subtle tonal shifts caused by different types of capacitors might actually be audible, after all, don't we unanimously agree that ceramic caps don't sound as good "in the signal path" as other types of caps like film? Clearly, there are differences that can not only be measured but heard, when dealing with a two caps of mfd value and of different material, or even just different mfg method with a same material, such as a multilayer vs a single layer, etc.

I think one of the reasons people assume it wouldn't make a difference may not only relate to their own inability to perceive it (just as someone with a tin ear may not want to admit they cant hear a difference in their prized buy item, so, too, will the tin ears who do not use the "mojo" parts will refuse to acknowledge they may have been doing it wrong as well) is that these devices are also so physically small, which trips them up. If we were talking about the bore size of an 8 cylinder car, a few mm makes a noticeable difference, yet in contrast to the actual size of the engine, this difference is extremely miniscule (and remember, we're amplifying the most subtle differences into big noises!).

Taking the same thing down to the scale of capacitors, why should we not hear a difference? And then again, we have not only repeated tests performed by multiple independent people at different times, we also have hysteresis charts, scientific study on the white matter in the brain that can determine our "auditory acuity", and so on, while the nay-sayers have... what? A gut feeling? A claim that they don't hear a difference themselves, and there has been no rigorous testing to prove without a shadow of a doubt that such differences are audible to people? Where's their logic or scientific or even amateur evidence to support their claims? Smoke. Vanished.

Furthermore, while at the same time claiming that a much more controlled test needs to be done, the nay-sayers have gone to great lengths to avoid performing these tests themselves and providing the double blind study in a youtube or vocaroo clip that once and for all could put the matter to rest, by drawing up huge sample sizes and comparing them to statistical probabilities.

It would be advisable that mojo parts are "the last thing" you get, comparable to buying a BMW shift knob for a volkswagon bug. It's not going to add much to that car as it would to a legitimate BMW. it may be a poor analogy, but I'm running out of F's to give for the moment, like a honey badger.

I've thought of a test, now.

Find two identical mojo and non-mojo parts, as per MFD, but not as per mfg or possibly even not as same material. The capacitances are identical. Insert a switch into the guitar to select for treble bleed of either one or the other. Turn the guitar as low as possible in volume, and turn any intermediary pedals, the gain, and the volume of the amp up to 10. Record that. See if there's a noticeable audible difference, and get some scope data on it. To strum the guitar strings and eliminate "user inaccuracy/not playing right in both tests", get one of those auto-strummer motors that someone posted on these forums before, so that the motor provides a consistent test behavior.

If we can scope out measurements of different frequency responses, like the guy micing his amp and graphically representing the outputs over the frequency ranges, and if we can or can NOT hear a difference before and after pulling back the curtain on the wizard a la the graphic charts in side by side comparisons, then we should be able to consider the matter settled once and for all.

All that has to be done is put the test parts at the quietest part possible in the signal chain (low volume guitar), and amplify it over and over with a number of units, to be sure that any differences are clearly audible to even the person with the most Tinny of ears.

That's my proposal if one of you debunkers would like to get working on it.
Title: Re: Paper in oil caps
Post by: FiveseveN on August 06, 2013, 08:42:34 AM
while the nay-sayers have... what?

I'll tell you what they don't have: the burden of proof.
Title: Re: Paper in oil caps
Post by: midwayfair on August 06, 2013, 08:54:04 AM
I agree about "small sample sizes", however, the point was that it's extremely telling that one person got the answers PERFECTLY 100% backwards, indicating that they could differentiate between the two

No, you still can't make that determination. It's not necessarily an unreasonable assumption, but it still can't rise above assumption with the data available. You have no baseline or comparative tests to determine that they were able to do so beyond mere chance.

Disclaimer: Math ahead. I suck at math. But I'm pretty sure the calculations are correct.

There were 10 sound samples total, divided into two pairs. That's 5 coin flips. The probability of guessing all five in a row is 3.125%. It's not an unreasonable assumption that they guessed and happened to get it right: each contestant is posting in public, and it does no good to post the same answers as another person who posted before you,* so each answer can be treated as unique. You only need 32 people to guarantee both a correct answer and a 100% wrong answer, and in a sample size of 16 contestants the probability to get either a correct answer or a 100% wrong answer is essentially a coin flip. There were about 20 "contestants." That means that the probability of getting either was greater than chance (62%). In other words, a group of 20 deaf people could have reproduced this result, and a group of 32 deaf people would have produced a winner.

Again, I don't have a horse in the cap race, but as a former science editor I think it's important for people to look critically at data and how they're used in an argument.

*Let's just assume that the people posting were smart enough to do this ... I'm not going to catalog the answers to find out if they were, and even if they weren't it doesn't necessarily invalidate the argument.
Title: Re: Paper in oil caps
Post by: Thecomedian on August 06, 2013, 08:56:51 AM
while the nay-sayers have... what?

I'll tell you what they don't have: the burden of proof.

anyone who makes a claim has a burden of proof. There is at least some scientific evidence supporting the theory that audible differences are possible. There is no scientific evidence supporting the fact that there are no audible differences. Do you understand that both sides have a burden of proof?

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each contestant is posting in public, and it does no good to post the same answers as another person who posted before you,* so each answer can be treated as unique.  

That's an incorrect assumption. You need to get the answer right, not to have your answer differ from others. There were as many prizes possible as correct answers given by the posters, up until the cut-off date where it was all tallied. The trick to this particular shell game was correctly calling the klon from the other pedal, which is where the real "coin flip of the game" was.

so, no, you can't treat all answers as unique. It'd be like having a math problem on the board for kids to do and get a reward after each kid does the problem in front of the rest of class and everyone has already done it, and then all the kids try to get different results to "randomly win". It doesn't make sense compared to actually trying to answer accurately.
Title: Re: Paper in oil caps
Post by: midwayfair on August 06, 2013, 09:17:30 AM
There were as many prizes possible as correct answers given by the poster

No, just three:

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The first three contestants to submit perfect scores

In either case, do you have any data to prove that any given poster was doing anything other than guessing each round? No, you don't. We know nothing about the contestants because they're anonymous posters on the internet. You can't even prove than they listened to the samples. You picked the least important aspect of my paragraph and dismissed the main point, that 20 different answers provides a greater than chance probability of producing either a correct or 100% wrong answer.
Title: Re: Paper in oil caps
Post by: Thecomedian on August 06, 2013, 09:26:41 AM
There were as many prizes possible as correct answers given by the poster

No, just three:

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The first three contestants to submit perfect scores

In either case, do you have any data to prove that any given poster was doing anything other than guessing each round? No, you don't. We know nothing about the contestants because they're anonymous posters on the internet. You can't even prove than they listened to the samples. You picked the least important aspect of my paragraph and dismissed the main point, that 20 different answers provides a greater than chance probability of producing either a correct or 100% wrong answer.

Quote

ontestant is posting in public, and it does no good to post the same answers as another person who posted before you,* so each answer can be treated as unique. You only need 32 people to guarantee both a correct answer and a 100% wrong answer,

If the latter logically follows from the former, I think it's a major point, since it indicates that "you only need 32 people" which inflates the probability into "acceptably plausible". that doesn't sound like chicken feed to me when the premise of your argument is that it has a high statistical probability there will be two perfect 100% or 0% scores.


again, you say 20 different answers, but are they 20 different answers? You ask us to treat each answer as unique, but the reasoning there is flawed because people don't want to give a unique answer, they want to give the right answer.
Title: Re: Paper in oil caps
Post by: induction on August 06, 2013, 11:58:31 AM
You ask us to treat each answer as unique, but the reasoning there is flawed because people don't want to give a unique answer, they want to give the right answer.

For his logic to work, they don't really need to be unique answers, they just need to be causally uncorrelated with previous answers.
Title: Re: Paper in oil caps
Post by: FiveseveN on August 06, 2013, 12:17:01 PM
anyone who makes a claim has a burden of proof.
Exactly. What you seem to ignore is the fact that tere are no "negative claims". Skepticism is just the reasonable default position where there is insufficient evidence to support a claim.
See Bertrand Russell et al for more information.
Title: Re: Paper in oil caps
Post by: midwayfair on August 06, 2013, 01:23:41 PM
I've thought of a test, now.

Find two identical mojo and non-mojo parts, as per MFD, but not as per mfg or possibly even not as same material. The capacitances are identical. Insert a switch into the guitar to select for treble bleed of either one or the other. Turn the guitar as low as possible in volume, and turn any intermediary pedals, the gain, and the volume of the amp up to 10. Record that. See if there's a noticeable audible difference, and get some scope data on it. To strum the guitar strings and eliminate "user inaccuracy/not playing right in both tests", get one of those auto-strummer motors that someone posted on these forums before, so that the motor provides a consistent test behavior.

If we can scope out measurements of different frequency responses, like the guy micing his amp and graphically representing the outputs over the frequency ranges, and if we can or can NOT hear a difference before and after pulling back the curtain on the wizard a la the graphic charts in side by side comparisons, then we should be able to consider the matter settled once and for all.

All that has to be done is put the test parts at the quietest part possible in the signal chain (low volume guitar), and amplify it over and over with a number of units, to be sure that any differences are clearly audible to even the person with the most Tinny of ears.

This is almost a good experiment.

You also need a random-ish method of alternating sound samples in under 2 s with an A/B button (or hand raising) for the test subject to press to identify each sound sample, with a large enough sample size to eliminate chance. You could ask a person, "did these sound different" and get a "yes" if the person doesn't want to give the impression that they couldn't hear something they were supposed to.

I'm not convinced that an auto-strummer sufficiently isolates the capacitor as the only change in each sound sample, but a large enough sample size should make that a wash. But since I'm not trained in research methodologies, I couldn't tell you how large a sample size per test subject is sufficient. You'd need preliminary scope data to determine how close the the auto-strummer can get.

Another problem: What is the test subject comparing to? You can tell them, "This is Sound A and this is Sound B" but they can't remember a baseline sound for more than 2 seconds, so any choice beyond the first switch will give no comparison for them to decide on pressing A or B. You need a way to run a double blind test and obtain a sample size that can rule out subject bias or chance while dealing with the human brain's inability to remember sound for longer than 2 seconds. The best I can come up with is: Every test is always "Sound A" first. The subject must press a button when Sound B is different. Do that several times over multiple sessions (to eliminate ear fatigue) with multiple people and you should have a decent set of data that can be testing in repeat experiments. That would be a robust experiment.
Title: Re: Paper in oil caps
Post by: induction on August 06, 2013, 02:16:37 PM
Slightly more robust, I think, would be to prepare several pedals with nothing in them but coupling caps hooked to dpdt stompswitches.  Some have two identical-value caps being switched, others have only one, and the switch does nothing.  In some of the pedals with two caps, both caps will be the same type, in others, different types.  Instead of just listening, let the test subject play through the pedals, switching at will. Then they state whether they think the caps are being switched or not. Answers are simple yes/no.

You generally want experiments to be as simple as possible, and I think playing instead of recording removes a lot of extra complications.  Youtube would be much worse because of the way they compress the audio.

The statistics wouldn't be hard once the numbers are in place. The test is designed to see if anyone tested can tell cap types apart, even if they can't identify which are which.  If you try to extrapolate the results to a population distribution, it gets a little harder, but if you just want to see if anyone can pass, sample size isn't a big concern.

The downside is you can't be both the subject and the person who prepares the boxes, which means it takes at least two people to do the test, and it can't be done remotely.
Title: Re: Paper in oil caps
Post by: wavley on August 06, 2013, 03:27:48 PM
You'll need buttons for all of these things if you truly want an audiophile quality blind test: "deeper lows and higher highs", "it was as if a veil was lifted", "more air around the performers", "enhanced micro-dynamics", "three-dimensional soundstage", "reach-out-and-touch the performers", "preserves the musical flow with a fabulous sense of body and an extremely tuneful midrange.", "Pitch certainty was superb.", "fast bass", "The lows are incredibly lush and defined", "Hateful tizzyness in the top end", "There was an absence of a sweet midrange colouration", "Transients increased at the expense of midrange texture and air", "The deep fundamentals leave you gasping for breath", and my personal favorite "The lack of multiple crystals should prevent inter-crystal diode effects".

And this...

To be completely honest, I don't care if the guy makes up stuff about his gear or not when it's your average interview, tell people that your amp has caps filled with dragon's blood for all I care or don't talk about your gear at all, but when it's a serious nuts and bolts talking shop with a peer interview at least keep it realistic.

I want some "formed" dragon's blood caps in my amp. How much do they cost?!  :icon_lol:

$100 each   I build them in the old Mallory toilet paper tube cap bodies so that they look 100% vintage, some of the leads are clipped a bit short and please ignore the bulging because it's hard to tame dragon's blood.  They will give your amp glassy highs, haunting mids, chewy low-mids, bell like attack, and a huge tight bottom end.

edit: I would also like to add this nugget of me being a jerk from the same thread

"You're being interviewed by a guy that can tell the difference between a Pre-CBS Fender and Vietnam era knock off guitar and you know it, but you still keep up the charade.  That would be like if I got famous and one of you guys interviewed me and I insisted that my fuzz face with two extra knobs built on cardboard had extra special mojo because the tone comes from the cardboard, and more specifically from Vintage Ikea cardboard from the Lagan countertop and while I was making it I had 2001 a space odyssey on betamax playing on a 1964 tube tv while druids danced around my living room drinking the dew of the first spring day.  When you know full well that electrons just don't work that way."
Title: Re: Paper in oil caps
Post by: gritz on August 06, 2013, 10:04:12 PM
You'll need buttons for all of these things if you truly want an audiophile quality blind test: "deeper lows and higher highs", "it was as if a veil was lifted", "more air around the performers", "enhanced micro-dynamics", "three-dimensional soundstage", "reach-out-and-touch the performers", "preserves the musical flow with a fabulous sense of body and an extremely tuneful midrange.", "Pitch certainty was superb.", "fast bass", "The lows are incredibly lush and defined", "Hateful tizzyness in the top end", "There was an absence of a sweet midrange colouration", "Transients increased at the expense of midrange texture and air", "The deep fundamentals leave you gasping for breath", and my personal favorite "The lack of multiple crystals should prevent inter-crystal diode effects".

And this...

To be completely honest, I don't care if the guy makes up stuff about his gear or not when it's your average interview, tell people that your amp has caps filled with dragon's blood for all I care or don't talk about your gear at all, but when it's a serious nuts and bolts talking shop with a peer interview at least keep it realistic.

I want some "formed" dragon's blood caps in my amp. How much do they cost?!  :icon_lol:

$100 each   I build them in the old Mallory toilet paper tube cap bodies so that they look 100% vintage, some of the leads are clipped a bit short and please ignore the bulging because it's hard to tame dragon's blood.  They will give your amp glassy highs, haunting mids, chewy low-mids, bell like attack, and a huge tight bottom end.

edit: I would also like to add this nugget of me being a jerk from the same thread

"You're being interviewed by a guy that can tell the difference between a Pre-CBS Fender and Vietnam era knock off guitar and you know it, but you still keep up the charade.  That would be like if I got famous and one of you guys interviewed me and I insisted that my fuzz face with two extra knobs built on cardboard had extra special mojo because the tone comes from the cardboard, and more specifically from Vintage Ikea cardboard from the Lagan countertop and while I was making it I had 2001 a space odyssey on betamax playing on a 1964 tube tv while druids danced around my living room drinking the dew of the first spring day.  When you know full well that electrons just don't work that way."


Post of the week! :icon_lol: :icon_lol: :icon_lol:

I see that the "son of noise gate" thread has just been locked - a few days after the parent thread got deleted. I guess that this is just further evidence that the World Of Pedals revolves around just two questions:

1) Which capacitor will make me sound like Hendrix?

2) How do I bias a transistor? And btw which transistor will make me sound like Hendrix?

Ok, that's three questions, but you get the point. It's getting old.

Regarding listening tests - it's tough to prepare a meaningful double blind test for internet consumption - and what's the point anyway? People on the two extremes of the argument tend not to be motivated by facts, but by faith:

"I want to believe"

"I don't want to believe what you believe"

It's not a new conflict and the "reasonable majority" who look for research from reliable sources, read datasheets and select components for pragmatic reasons + personal experience and the advice of people who actually know what they're talking about tend to just walk away becausethey know that if they interject they'll get grief from the extremists on both sides. These are people that communities can't afford to lose because they aren't controlled by dogma. Seriously.

If some people spent as much time practicing guitar as they did arguing about stuff that may not make any tangible difference then perhaps their tone would improve tangibly! And perhaps we would see some original ideas rather than the same old fifty-year-old gruel reheated.

As you were.

Title: Re: Paper in oil caps
Post by: intripped on August 07, 2013, 12:09:23 AM
premise 1: english is not my native language, so please excuse me if i express myself in a bad way
premise 2: i'm not an electronic engineer - actually i know electronics very little

why instead of trying to organize a consistent listening test which could provide reliable results, don't you just begin with some measuring around and see if there is actually any difference between two (or more) capacitors, with same capacitance and different dielectric\technology?

i'm thinking about a procedure using white noise and a spectrum analyzer, in order to obtain directly and easily comparable diagrams.
As you surely know, white noise is already used to make such measuring: you inject white noise at the input of a device and plot the frequency response at the output
doing this we could actually see the frequency responses of different capacitors, and we could also define if: there are differences - these differences are theoretically audible

i know, this is kind of a poor measure, because it doesn't consider the transients and the real dynamic situation, but anyway it could be interesting and maybe revelatory: i've never seen something like this properly done before

 ... and only as a subsequent step introduce a listening test, with all the subjective and unpredictable variables that this procedure inevitably provides.

Title: Re: Paper in oil caps
Post by: mistahead on August 07, 2013, 12:29:01 AM
I believe that the argument had, somewhere up there, descended into the idea that:

'scope measurements indicating a different waveform impact / secondary component value, in a range which is audible for a given application, where two components use different tech/methods to reach the same primary component values are not indicative of what the real world outcome will be.

Science is leaking.
Title: Re: Paper in oil caps
Post by: Jdansti on August 07, 2013, 12:39:20 AM
I was going to try to get caught up on the thread, but I don't want to make my headache worse. Without reading the last two pages, I'll just say that I agree with everyone.  ;)
Title: Re: Paper in oil caps
Post by: mistahead on August 07, 2013, 12:40:57 AM
Still the golden rule will always prevail - does it sound better in the build in front of you in the rig you're playing through, with the folks you're playing with, to the folks you're playing to?

If yes - well that is it.

If no... get new folks to play with and to.
 ;D
Title: Re: Paper in oil caps
Post by: induction on August 07, 2013, 01:17:46 PM
I believe that the argument had, somewhere up there, descended into the idea that:

'scope measurements indicating a different waveform impact / secondary component value, in a range which is audible for a given application, where two components use different tech/methods to reach the same primary component values are not indicative of what the real world outcome will be.

Science is leaking.

Pure logic does not tell us that differences between caps seen in an oscilloscope that fall outside of the range of operation of the part and circuit in question can cause an audible difference in a pedal.

Obvious strawman is obvious.

Oscilloscopes can tell you if two waveforms are different, but they can't tell you if anyone can hear that difference. For example, an oscilloscope can tell you that one waveform is inverted relative to another, but I doubt anyone could tell that by listening. The only way to know whether a difference is audible to someone is a hearing test. The question is itself subjective, but the test can be performed objectively.

In science, experimental data trumps theory, assuming the experiments were performed rigorously. If the question is about what you can hear, the answer is given by a hearing test. In any case, we have no physical theory that delimits what can be heard by humans. If we want to make predictions, we use guidelines that are based on hearing tests, not on physical theory.

Theory exists to describe and explain phenomena. In this case, the phenomenon is a human hearing a difference between two caps. Before using theory to explain how this happens, we need to know whether it actually happens at all. Otherwise, there's no phenomenon to explain.

I don't have a horse in this race. When I say I'm skeptical, I'm only saying that I haven't seen any evidence of the phenomenon in question, and therefore don't have a positive belief in its existence. That is the default position in science. It doesn't mean I have a positive belief in its nonexistence, though such a belief could be developed if I search for it and fail to find any evidence of it. All it takes is one counterexample to demonstrate that it exists, and I would modify my position. (That's how science works.) That counterexample will have to take the form of a hearing test.

I don't understand why this bugs you. Maybe you prefer your arguments between true believers and absolute deniers who make up their minds in advance of any evidence. That's not how science works.

Science is doing just fine, thanks.
Title: Re: Paper in oil caps
Post by: mistahead on August 07, 2013, 07:14:22 PM
I believe that the argument had, somewhere up there, descended into the idea that:

'scope measurements indicating a different waveform impact / secondary component value, in a range which is audible for a given application, where two components use different tech/methods to reach the same primary component values are not indicative of what the real world outcome will be.

Science is leaking.

Pure logic does not tell us that differences between caps seen in an oscilloscope that fall outside of the range of operation of the part and circuit in question can cause an audible difference in a pedal.

Obvious strawman is obvious.

Oscilloscopes can tell you if two waveforms are different, but they can't tell you if anyone can hear that difference. For example, an oscilloscope can tell you that one waveform is inverted relative to another, but I doubt anyone could tell that by listening. The only way to know whether a difference is audible to someone is a hearing test. The question is itself subjective, but the test can be performed objectively.

In science, experimental data trumps theory, assuming the experiments were performed rigorously. If the question is about what you can hear, the answer is given by a hearing test. In any case, we have no physical theory that delimits what can be heard by humans. If we want to make predictions, we use guidelines that are based on hearing tests, not on physical theory.

Theory exists to describe and explain phenomena. In this case, the phenomenon is a human hearing a difference between two caps. Before using theory to explain how this happens, we need to know whether it actually happens at all. Otherwise, there's no phenomenon to explain.

I don't have a horse in this race. When I say I'm skeptical, I'm only saying that I haven't seen any evidence of the phenomenon in question, and therefore don't have a positive belief in its existence. That is the default position in science. It doesn't mean I have a positive belief in its nonexistence, though such a belief could be developed if I search for it and fail to find any evidence of it. All it takes is one counterexample to demonstrate that it exists, and I would modify my position. (That's how science works.) That counterexample will have to take the form of a hearing test.

I don't understand why this bugs you. Maybe you prefer your arguments between true believers and absolute deniers who make up their minds in advance of any evidence. That's not how science works.

Science is doing just fine, thanks.

Are you arguing with me over one of the points we agree upon?

Don't start lecturing on science son.
Title: Re: Paper in oil caps
Post by: FiveseveN on August 07, 2013, 07:49:03 PM
But it isn't at all clear what you do agree on. Someone seems to be playing the "it takes more faith to be skeptical" game.
Allow me to rephrase the "should it be audible" question in a way that I hope to give a new perspective on your argument: Do you agree that we have test instruments (scopes, spectrum analyzers) that outperform the auditory system of any human (in bandwidth, dynamic range, distortion, noise etc.)?
Title: Re: Paper in oil caps
Post by: gritz on August 08, 2013, 02:15:57 AM
But it isn't at all clear what you do agree on. Someone seems to be playing the "it takes more faith to be skeptical" game.
Allow me to rephrase the "should it be audible" question in a way that I hope to give a new perspective on your argument: Do you agree that we have test instruments (scopes, spectrum analyzers) that outperform the auditory system of any human (in bandwidth, dynamic range, distortion, noise etc.)?

It's possible to measure lots of stuff that is absolutely inaudible to the human ear - the most obvious one being volume differences of much less than 1 dB. Unfortunately, simply knowing that two signals are different is enough to change our perception of them. I've fooled myself like that plenty of times! That's why it's important that all tests are best done under controlled supervision, where people like me can't try to cheat - just putting samples out on the interwebz is open to all kinds of abuse. It's also possible that the person preparing a comparison demo of two different bits of hardware might modify their playing (even subconciously) according to which piece of hardware they're playing through. The power of suggestion is strong. A better test might be to pre-record guitar samples and then reamp each piece of hardware with the same samples. This does however make it easier for people with analysis hardware to spot (perhaps inaudible) differences, which is why tests should be supervised. The particular hardware under test might "prefer" being plugged into a real guitar too (as classic fuzzes and wahs tend to be).

These threads are generally a bit flawed in that people end up arguing about vanishingly small differences that are only perhaps audible to a very select few (assuming in a particular case that there is any difference at all), whilst mojo-hounds often claim night-and-day differences. They can't all be right, yet it's treated by many as a black and white argument. People who sit on the fence and say "prove it" get stick from extremists on both sides, 'cos it's basically a religious argument. "I do / do not believe. Ergo you are a heathen savage / slave to dogma." *Delete as applicable.

And without putting people in MRI scanners, or giving 'em brain implants how can anybody be certain of what another person actually does "hear" (perceive)?

As far as I'm concerned people can believe what they like as long as they don't mislead newbies. But they do.

Edit: one very good source of information on human hearing / perception is research regarding hearing aids. There's a lot of it available on the web, but it's deep stuff. Psychoacoustics is complicated, but it's not magic!
Title: Re: Paper in oil caps
Post by: wavley on August 08, 2013, 09:43:19 AM
(http://www.rane.com/jpg/pi14fp.jpg)

(http://www.rane.com/jpg/pi14ch.jpg)

http://www.rane.com/pi14.html (http://www.rane.com/pi14.html)
Title: Re: Paper in oil caps
Post by: gritz on August 08, 2013, 01:13:26 PM
(http://www.rane.com/jpg/pi14fp.jpg)

(http://www.rane.com/jpg/pi14ch.jpg)

http://www.rane.com/pi14.html (http://www.rane.com/pi14.html)

That is the coolest thing I have ever seen - do you have a verified schematic?

It reminds me a little of this software gem:

(http://bram.smartelectronix.com/images/room.png)