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Tone capacitors
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Author:  TonyM [ Sun Dec 02, 2012 3:21 pm ]
Post subject:  Tone capacitors

I know there is a great deal of debate concerning the different types of tone caps and their effect on tone when it comes to electric guitars. Certain types are hearlded as the best, Bumble Bees, Vitamin Q, Orange Drops, etc. I know it is difficult for me at least to hear tonal differences with different type capacitors of the same value. I have heard slight differences. I can hear the difference in tone for sure when it comes to cap value. Would there be a way to wire up mutiple tone caps of different values inside the guitar full time for different tones?

Like a five way selector with a different type or value cap at each spot on the selector. Say if I coil tapped I could also switch to different tone cap. It would seem to be a novel way to get different sounds out of one guitar. I have not messed with different tone caps brands or values personally at all, but have listend A/B examples and can tell a difference. Would this be practical or worth the trouble?

Author:  nyazzip [ Sun Dec 02, 2012 3:40 pm ]
Post subject:  Re: Tone capacitors

heres a pretty good link, but part 2 i did not find.

http://www.premierguitar.com/Magazine/I ... itors.aspx

in my opinion, beyond selecting the right voltage and capacitance values, and maybe avoiding electrolitic caps, everything else is cork sniffery BS.
it might make more of a difference in the hifi world, but not in the guitar world. for example, most vintage guitars(and amps!), which are now "Holy Grails", used ceramic disc capacitors in the tone circuits, which modern day self-declared tube gurus all turn their noses up at.
to put it politely, electric guitarists are not a very objective bunch...and don't get me wrong, i consider myself an electric guitarist!

Author:  B. Howard [ Sun Dec 02, 2012 4:20 pm ]
Post subject:  Re: Tone capacitors

I think you'll find most tone junkies prefer to get their fix from front end signal processing rather than at the source. It allows far more flexibility in shaping the tone and can make the choice of instrument almost a non issue which can be real important at a gig when that guitar is on the fritz. A stomp box EQ can be had for as little as $30 and even nice rack mount gear is not all that expensive today.

Now I will say that switching out the coupling caps in my tube amp for some silver-mica ones definitely made a big change. Much more sparkle, noticeably brighter.

Author:  klooker [ Sun Dec 02, 2012 8:10 pm ]
Post subject:  Re: Tone capacitors

TonyM wrote:
...Would this be practical or worth the trouble?


I think that's up to you. If you take the time to understand the circuits, I'm sure you can make it work.

If you hear significant differences going from different cap values, then I think it would be worth your time.

Kevin Looker

Author:  Rodger Knox [ Mon Dec 03, 2012 12:13 pm ]
Post subject:  Re: Tone capacitors

In a guitar circuit, you can hear a difference from different cap VALUES, but not from different cap TYPES, at that current and voltage they all behave exactly the same. That's not true in a tube amp circuit.

Author:  JEguitars [ Mon Dec 03, 2012 5:01 pm ]
Post subject:  Re: Tone capacitors

I make my own oil capacitors, very easy to do and a lot of fun actually.

Author:  RogerC108 [ Mon Dec 03, 2012 5:03 pm ]
Post subject:  Re: Tone capacitors

The old Esquires did a version of what you're wanting to do. They had 1 pickup with a 3-way selector. 1 position was dedicated to a high-value cap to give it a really dark tone.

Image

Author:  Steve Davis [ Mon Dec 03, 2012 6:42 pm ]
Post subject:  Re: Tone capacitors

http://www.bigdguitars.com/varitone.html

The varitone 5 way switch standard on 335's was something like this'
This guy makes one that is super easy to install at a very reasonable price.

Author:  TonyM [ Sat Dec 08, 2012 8:13 pm ]
Post subject:  Re: Tone capacitors

I should have figured it had been done by someone before. Might try it. There is also an interesting new volume pot that when you turn all the way up it then clicks bypassing the pot totally sending full output straight to the output jack. They claim it's like an 11 switch for instant more output.

Author:  nyazzip [ Sat Dec 08, 2012 8:53 pm ]
Post subject:  Re: Tone capacitors

Quote:
There is also an interesting new volume pot that when you turn all the way up it then clicks bypassing the pot totally sending full output straight to the output jack.

you could achieve the same with a toggle switch, but i guess its kind of nice to have it built into the pot....

Author:  TonyM [ Sat Dec 08, 2012 9:15 pm ]
Post subject:  Re: Tone capacitors

Yep switch would work, but just swaping pot out like you said keeps you from drilling extra holes. The only thing I dont like about the varitone is the caps he uses, all ceramic. I would at least go higher quality.

Author:  Chameleon [ Sat Dec 08, 2012 10:19 pm ]
Post subject:  Re: Tone capacitors

Just get a rotary switch with as many positions as you want capacitors. They're cheap on ebay. Lots of people use this instead of a tone pot, but you could also wire it to a pot if you want, but it will be another knob on your guitar. Note: The really cheap rotary switches take some muscle to turn, and you'll need to bolt them super tight if you don't want to loosen it switching caps.

You know I've got some extra holes in one guitar I have, I might do this just to fill the space. Happy wiring.

Author:  David Collins [ Sun Dec 09, 2012 2:26 am ]
Post subject:  Re: Tone capacitors

I have some unique experience here, so I'll chime in on this one.

This topic never ends, and like many things which border on the metaphysical (seemingly undeniable effect by those who experience it, complimented by quasi-scientific explanations which give some air of plausibility), it will never cease to stir debate. So I've done some testing, and tried my honest best to be impartial and prepared to accept the possibility of the seemingly inexplicable to be supported by evidence.

First step, tests have to be well controlled and well thought out. Psychosomatic effects exist. The McGurk effect exists. The same aroma makes people salivate when they are told it is a French cheese yet vomit when told it is a body odor, and the most expert wine tasters will often rate the same wine higher when they see it poured from a more fancy bottle or one with a higher price tag.

All this stuff is hardwired in to us, so if you want to test direct influence your tests need to be blind. Double blind. Super Extreme Mega Blind. I've studied many published and academic psychoacoustic testing methods and tried my best to remain true to their models. Few testers bother with this, so few tests should be viewed as having much (if any) merit in my opinion.

Step two - drop the metaphorical descriptors. No asking which is warmer, or muddier, or brighter, or more spicy or oozy or fruity. Best bet is to go with the "odd one out" test, like Sesame Street. Several examples of one type, one different, which one of these things is not like the other?

So I started by dumping out a bunch of caps -

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Test them all and group them in to consistent tested ranges -

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Then I wire them (ceramics vs PIO) in to a test arrangement on a Strat with a few rotary switches. A series of four tests correlating to four positions on the first switch, one simulating a tone on 10, the next simulating tone on 3, next tone on 3 with the caps rearranged, and finally with tone on 0. In each test phase players were to switch between 3 positions on a second switch, and answer which one was different from the other two.

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Results? Random. Complaints by believers about flaws in the tests? Innumerable. So I go back to the drawing board.

Cap test 2.0. Polyester (if I recall correctly) vs boutique PIO. External box, 6 different test sessions, five selections in each (each time four of one type, one of another, all tested at consistent values). Tests 1-3 disengaged the pot and substituted a fixed capacitor simulating a pot at full value, with the "odd one out" being a straight wire (soldered staple actually) rather than a cap in at least one of these "tone on 10" tests. Tests 4-6 allowed use of the tone pot to test at lower values all the way down to 0.

Image

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Again, survey results random, hypothetical concerns of interference abundant.

On to the next test. To allow for any arrangement of pots, cap types, values, tapers, coil vs output loading, etc, I made the ultimate versatile test box. You name it, this can simulate it (for one vol/tone line at a time anyway).

Image

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Internal adjustable range cap, and up to 3 external caps, plus I can even test signal running through the cap as a bass cut rather than conventional tone. Results, as far as I've fiddled with it, still nada.

Of course there's a lot going on here, so it's better to go back to basics. On to the next version.

This time it's a new box that's easy to switch out to different guitars, switch out for different caps, is designed and tested for extremely minimal residual capacitance and resistance (less than a foot of typical guitar cable), and easy to use.

Image

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Get out the bumblebees, waxies, etc, and pick out a pair of good ol' true Gibson PIO .022µf's.

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Then test and match them to some cheapo ceramics and install them in random order.

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Now just remove the tone cap from any guitar, clip this box in in it's place, and you can switch between caps in real time, as the player is playing without missing a beat and listening in person, and all they have to do is tell you which one is different from the other three positions, A, B, C, or D. Open the box, have a third party randomly rearrange the caps out of sight, close it up, play, listen, repeat.

Results - I'll get back with you when I can find anyone able to consistently pick an odd one out between different cap types of the same tested value in a traditional passive guitar tone circuit. I've drilled some pretty good ears, and haven't found anyone who can do it yet.

This is a brief summary, and I obviously haven't expounded on all the details here. I've tested many more variety of caps than shown here, I've kept tolerances incredibly close, I've taken steps to include tested leakage (intentionally introduced to favor possibility of positive results), I've closely monitored residual capacitance and resistance and effectively ruled them out as potential interference - if you have a concern of the reliability of the tests or results, I've heard it from others and taken it in to account in successive test designs and evaluations. I've argued this topic enough (obviously), and I'm not going to argue it any more. If anyone has a better approach which is equally reliable and repeatable, by all means go for it and post your results. As a skeptic, I still hold pledge to be open to contradictory results if they meet basic standards of reliability, but I've just not seen any yet.

Until then I can say with confidence - to the best of my knowledge, it's all hogwash. Stick a Power Balance bracelet in your control cavity and it will yield results greater or equal to a boutique cap.

Thanks, and I'll take my answers off the air.

Author:  nyazzip [ Sun Dec 09, 2012 2:56 am ]
Post subject:  Re: Tone capacitors

Quote:
Results - I'll get back with you when I can find anyone able to consistently pick an odd one out between different cap types of the same tested value in a traditional passive guitar tone circuit. I've drilled some pretty good ears, and haven't found anyone who can do it yet.

....and there ya go. :D
Quote:
I can say with confidence - to the best of my knowledge, it's all hogwash. Stick a Power Balance bracelet in your control cavity and it will yield results greater or equal to a boutique cap.

...good luck convincing the electric guitar players who are desperate to blame anything other than themselves for not being the next (submit name of '60s-'70s rock guitar god here)!

Author:  B. Howard [ Sun Dec 09, 2012 5:48 am ]
Post subject:  Re: Tone capacitors

Here is a great article from Seymore Duncan's web site, talks about different caps and has soundclips of them. Real informative.
http://www.seymourduncan.com/tonefiend/ ... your-caps/

Author:  Stuart Gort [ Sun Dec 09, 2012 1:18 pm ]
Post subject:  Re: Tone capacitors

I suppose you could take an eye out changing strings, drop a guitar on your foot, or electrocute yourself...but since the structural integrity of an electric guitar is not critical to your health and therefore, thorough engineering is not required, the subject will attract all manner of mystics....and does. :)

Harry Houdini spent most of his life discrediting mediums and mystics...a man after my own heart.

Test all assumptions.

Way to go David. That's how it's done!

Good link Brian.

Author:  John Coloccia [ Sun Dec 09, 2012 2:03 pm ]
Post subject:  Re: Tone capacitors

FWIW, I use cheap ceramic caps. IMHO, there's no reason in the world to hog up control cavity space with anything else. If you really want to splurge and get +/-5%, spend $.70 each and buy Mica capacitors.

Author:  Rodger Knox [ Mon Dec 10, 2012 11:05 am ]
Post subject:  Re: Tone capacitors

Rodger Knox wrote:
In a guitar circuit, you can hear a difference from different cap VALUES, but not from different cap TYPES, at that current and voltage they all behave exactly the same. That's not true in a tube amp circuit.

I'm pretty sure the first part of this is based on a previous post of David's research.

Author:  Chameleon [ Mon Dec 10, 2012 4:45 pm ]
Post subject:  Re: Tone capacitors

Bravo.

Author:  TonyM [ Thu Dec 13, 2012 10:32 am ]
Post subject:  Re: Tone capacitors

Thanks much for your post Dave. That's the kind of hard proof I like to see. Very well done and thought out test.

Author:  dzsmith [ Sat Dec 15, 2012 9:34 am ]
Post subject:  Re: Tone capacitors

Peavy has an interesting tone pot wiring scheme for humbuckers:
The pot is between the coil tap and ground. The pot wiper goes through a cap to the ouput.
The theory is that in one direction the pot will ground out the tap and give a single coil output, the other direction will cut off the high frequencies in humbucker mode. Kind of a tone control from single coil to humbucker.
Never tried it, but I don't use tone pots.

Author:  hugh.evans [ Sun Dec 16, 2012 4:28 am ]
Post subject:  Re: Tone capacitors

David- fantastic work to say the least. It's unfortunate that dispite thoroughly disproving any mystical properties of capacitance, many guitarists who believe in their golden ears will claim there is still a difference. It reminds me of a story my father told me from his days working at Baldwin piano conducting listening tests with professional musicians. Invariably the only predictor of the preferred instrument was volume: the loudest was always perceived as the best.

I look forward to seeing the results from the active pickup/state variable tone circuit I've designed. The amount of flexibility borders on absurd. It could prove entertaining to run a double blind test telling players that it is an advanced new passive system vs active, or any number of other explanations. My hypothesis is that the information gathered would be more useful for marketing purposes than product design. I recall reading a study of people's preferences in tone between a recording of a mic'd amp in a studio and the same setup simulated with a POD. The POD was judged to be superior, and even more so when listeners were told the recorded POD was the real vintage tube amp.

Even in science I've seen the brain's desire to find rational patterns obscure objectivity. Once I spent over two hours explaining to a former boss that his perceived anomaly in a data set could be ruled out as noise due to statistical insignificance. Despite science being on my side he refused to accept that something that consistently appeared to be a pattern could be noise and demanded further review of additional variables present in test conditions. The scary thing is that he has a BS in chemistry and should be expected to have well honed scientific objectivity.

Enough of my rambling. Needless to say: the human mind is a baffling thing.

Author:  alan stassforth [ Sun Dec 16, 2012 3:04 pm ]
Post subject:  Re: Tone capacitors

Thanks David!
My thoughts on caps go like this.
I don't think the type has much to do with tone in a guitar.
I do use oil filled caps there,
because I think they look cool,
and you can tell people it's in there, ha!
I think the difference is heard when higher voltage runs through them.
I believe the oil caps pulsate, so you get a boingier tone in an amp.
A friend gave me 2 amps to work on.
Without looking inside this old tube Univox,
I played through it, and thought "this has oil filled caps".
Sure enough, every cap was oil filled.
Then I played through his little Gretsch amp and thought
"this thing sounds like it has ceramics".
Sure enough, every cap was ceramic.
The Univox sounded more musical,
and the Gretsch sounded more spikey, cold,
and nastier.

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