Official Luthiers Forum!

I'd posted on this here before, but just put up a video with a demonstration and survey comparing ceramic tone caps against a vintage paper in oil Sprague bumblebee of the same tested value. Have a look / listen and let me know what you think -

http://youtu.be/817JHiYV_Po

[youtube]817JHiYV_Po[/youtube]

We're going to start putting up a lot more interesting videos as well, from tools and techniques to other tests and comparisons, so feel free to subscribe to our YouTube channel to get new clips as soon as we get them up.

Thanks!

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sheer rubbish.
all of the "holy grail" '50s and '60s guitar amps and guitars are full of ceramic disc capacitors.....in hifi, maybe there are positions in the circuit where ceramic disc is not the best choice, but electric guitars and hifi music reproduction are two different animals

Oil caps have a huge sonic difference where high voltage is present.
I use them on guitar tone pots, because they might have an effect on tone.
Not much money more,
unless yer building many!

Materials make NO difference in tone for electric guitar tone capacitors. Values do make a difference, and they usually are not exactly the specified value, manufacturing specs are frequently +/- 10% or even +/- 20%. If you're trying to match the tone from a particular guitar, measure the actual value of the tone cap, that's more important than the material from which it's made.

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A man hears what he wants to hear, and disreguards the rest. Paul Simon

If you want a really cool tone knob, replace the pot with a rotary switch with different value caps.

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wah
Wah-wah-wah-wah
Wah

Just out of curiosity, did anyone actually watch the video?

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Hi Dave,
I watched the video and filled out the survey. I like the way you set up the test, simple and straight forward. Can you hear a difference or not.
I don't have very good quality speakers hooked to my computer and could not really discern much of a difference except on test 5. In retrospect, perhaps it wasn't fair to take the survey since my listening conditions were not ideal. I will listen again at a friends house who has better equipment and see if it makes a difference in my results.

Steve

Thanks Steve.

Through a good set of speakers or headphones I can hear a pretty clear difference in test 5, but I can't say the same for the other four. I could guess on what I think I might be able to hear, but it would be a pretty shaky guess at best. Unfortunately I can't even check to see if my guesses are right because the records of the actual positions are sealed away where I can't look at them until survey results are closed and evaluated. I hope to have enough survey participants to close it and evaluate the results by 12/28, so I can employ my father-in-law's help in fair evaluation (math PhD, retired university statistics professor) at the family holiday gathering.

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i watched about half of the video. didn't notice a thing regarding changes in tone: you can make the finest recording in the best studio with the most exquisite microphones, but when you upload it to Youtube, all that painstaking detail gets squashed into a low quality MP3...so there's that. but i guarantee you, all these experiments were done back in the '40s, and there is good reason why the most revered electric guitar recordings in history, whether it be jazz, rock, fusion, whatever, were done using standard/production equipment- because it doesn't matter. excellent and timeless music has very, very little- i daresay zero- to do with boutique or rare electronics and instruments...i guess i have just grown weary of this school of thought, that it must be the equipment that is a barrier to success.....good musicians can play rubbish instruments/amps and produce wonderful music; poor musicians frequently play top shelf gear, and manage to produce crap. the holy grail thing just seems like a useless avenue to be walking down and it is a pet peeve of mine i guess. sorry for being abrasive; i seem to excel at it.

nyazzip, while I don't disagree with your points (aside from prior testing to this effect being done in the '40s, which I do not believe was ever considered for this context), I think you may be missing the point of the whole video.

It could be said that the underlying purpose of this test is not so much focused around capacitors at all, but rather challenging people's certainty of their own infallible objective accuracy of sensory perceptions. The YouTube compression really isn't all that bad in my experience, as I can record samples which demonstrate very tiny differences audible in full quality uncompressed playback, and if playing through a good set of monitors still hear those differences just as well after it goes through the youtube processing. So for something to be so small as to be lost in this compression completely, even when focusing on relative changes in real time comparisons (very key point here) rather than final ultimate tone quality, it would have to be an incredibly small effect indeed.

If you look around the interwebs, you'll find no shortage of videos and sound samples posted where scores of listeners do hear a difference between cap materials, and hold absolute certainty that these differences are a direct result of differing capacitor types, completely dismissing the possibility of the player's attack and/or the listener's perception being unknowingly affected by their knowledge of a component being changed. This video offers an honest opportunity for them to reinforce their position by demonstrating that they can identify the difference they so easily seem to peg in other YouTube videos, but in a blind test where neither the player nor the listener knows which cap is engaged at any time.

Like you, I have a pretty clear position on this based on my own knowledge and experience of the issue, but I did my best to protect the test results from my own predispositions, and instead offer an honest and idealized opportunity for others to prove me wrong. If I'm wrong I have the right to know, but from the results so far I don't see it likely that I will have to concede my original position or follow up with any more testing.

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Hi David,

Based on my experiences the value of a capacitor is the deciding factor for tonal variances.

I don't believe youtube is a very good source for a critical listening evaluation so I won't be spending
time with it. Good luck with it though.
( I do have a very nice recording DAW and have spent 50+ years with guitars/recording so bull-headed about my audio opinions LOL)

I did watch some of the video, but when I couldn't hear any difference in the first three or four tests, I quit since I didn't expect to be able to hear any difference. If I can hear a difference, there usually isn't much of a debate, everybody can hear it!

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A man hears what he wants to hear, and disreguards the rest. Paul Simon

Right, never mind. This group may not be the ideal audience for things such as this.

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David, the problem is that except for some very subtle issues...like the dissipation factor...you are going to hear more differences due to capacitance tolerances among caps than due to materials. Tone control caps pass what you are NOT hearing, not what you are hearing. They drain highs to ground. This is much different from how coupling caps work in audio circuits where the material is very important.

A great way to test this, though, would be to use a single recording of a guitar and run it through an active circuit that has a passive tone control in the circuit...in other words, take the "live" playing out of the test entirely. Then you would have exactly the same signal source material to which you could listen and make the cap substitutions. Also, you simply must accurately measure the caps and match them within 1% if any test is to be valid. With typical + & - 10% parts, you could very well have a swing of 20% between two equally rated parts, and that would indeed be very audible.

The D-TAR "Eclipse" circuit that I use in my Model 1 guitars has a buffered passive tone control circuit, and it would be possible to take out the SMD cap on the board and solder in a test box. Using something like this would help isolate variables.

Thanks Rick. I agree that running a recorded sample through a passive tone circuit would affect greater consistency and more reliable sample measurements, but this test was targeted toward a particular audience which remains in denial, believing that anything other than an unadulterated guitar being played through a decent tube amp somehow alters or obscures the mojo that happens in real application. You know the ones I'm sure - "you can show me all the graphs you want, but they must be missing something because I know what I hear with my ears when I put a bumblebee in my guitar". Of course I've seen several tests by others clearly demonstrating no change in this application in 'lab tests' with sweeps and samples and frequency analysis, but no reliable blind listening surveys to address the "my ears are better than your scopes" crowd.

Of course I know there is no convincing many of these people, but this was something of a "well show me then" demonstration. Of course the survey results appear completely random so far, and I'm sure believers will blame it all on youtube compression (never mind that they all seem to hear differences in other non-blind youtube comparisons), but I thought it was a fair chance for them to prove me wrong none the less.

As an honest skeptic I had to design the test to protect it from my own bias (regardless of how logical and evidence based it may be), so I did my best to provide ample and ideal opportunity for listeners to identify a difference if there were any, while also protecting the test from me sabotaging it to favor failure.

I met with my statistician father-in-law yesterday, and am comfortable that there are enough results in to yield fair analysis. In the coming weeks I will do a follow up video focusing on more on why people often hear differences when no real electrical effect has occurred, yet loose their ability to identify a difference when the test is done blind.

I knew coming in to this forum that I'd be preaching to the choir that expensive boutique caps are snake oil, but I was just trying to get the video out as widely as possible to increase survey participation.

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Only because it sounds so negative; If I were building a guitar and the owner wanted "snake oil" for whatever reason(s) and would make him/her that much more pleased then I would be the last one to try and convince them otherwise.
I personally don't see the cost of caps at such a premium that trying to change anothers opinion worth it, for them or myself. If they spend a few more dollars for their "snake oil" and IF the only benefit is their belief that all is better...well good for them.

Those that want to know the funtioning and costing factors can easily learn the details and make their own determination. I feel I must add that those that can't...well snake oil may be exactly what works best for them and who am I to argue with that?

Just my take David and still wish you well with your trip and have fun.

You may want to post this over on AGF, the membership there may be a better sample since they're mostly players, and they get a lot of traffic.

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A man hears what he wants to hear, and disreguards the rest. Paul Simon

AGF for advice on an electric guitar issue?

Roger. Unfortunately their rules do not allow the likes of me unless I either go anonymous or pay a very hefty ransom. Most forums will encourage or require disclosures of association with any business. The AGF however, required a $300/mo sponsor fee if I chose to list my credentials or business name in my signature. After my counter offer for them to in turn pay me $301/mo for the professional consulting I would be providing their members was rejected, we kindly parted ways.

Michael, I'm sorry, but I must say that I disagree quite strongly. If something doesn't do what it's said to do then it's BS, and I don't think I'm doing anyone a disservice by demonstrating it as such (save for perhaps the snake oil salesmen). There's nothing wrong at all with wanting fancy parts in your guitar which serve no function beyond bling and pride, but if they're sold with the promise of affecting a change which they can't deliver unless you really want to believe in it, then I'll call it for what it is - snake oil.

The follow up video will be a public service announcement for anyone seeking honest, accurate, and transparent information, you're welcome in advance.

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[quote="David Collins"]Michael, I'm sorry, but I must say that I disagree quite strongly. If something doesn't do what it's said to do then it's BS, and I don't think I'm doing anyone a disservice by demonstrating it as such (save for perhaps the snake oil salesmen). There's nothing wrong at all with wanting fancy parts in your guitar which serve no function beyond bling and pride, but if they're sold with the promise of affecting a change which they can't deliver unless you really want to believe in it, then I'll call it for what it is - snake oil.

quote]

David, no need to apologize because we see this differently.

It should be noted that you refer to marketing and specifically of false claims but unless I misunderstood, your test is for those that purchase the goods- not sell them although now I'm not really sure...

If your test is to challenge vendors for false advertisement then good for you. But if there is truely false advertisement then why not just sue them and put a stop to it?
If your test is to prove to those that believe spending a few dollars more for something they believe works best for them- then that is where we are very different.

I don't care if the athelete that wears the same pair of socks every game thinks it brings good luck...so why would I care if those that believe a few dollars more buys them a cap that helps give the sound they may think is better?
Most of all, why would I want to change their minds? I wouldn't....but I think that you would.

Wow. Okay, I give up.

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Hope it helps and don't feel bad. Coke tried to teach the world to sing in perfect harmony and from what I hear..it didn't go so good either.
Hey David...still wish you good luck with it FWIW even if I don't get your point(s).

With all due respect, this much is quite obvious.

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I believe what is obvious is that you think there are people selling caps with false advertisements and people that
believe caps have tonal characteristics and you are going to put them to the test.
The point I don't get is simply, why?

I've dealt with musicians most all of my life and when one believes that a certain piece of equipment has that special something...you're not going to change a thing. That's just my opinion though and I can see you're going to be banging your head a lot more before all is said and done.

Sorry I have such a different view...it's obvious that you don't like that so I'll trouble you no more about it.

For those interested, here's the follow up summary and review of last month's survey.

http://youtu.be/M7Hu52vmxE0

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