Capacitor Selector Switch

Discussion in 'Tele Home Depot' started by Binx, Sep 19, 2019.

  1. Binx

    Binx TDPRI Member

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    Hi guys, I ran across this article and thought it was kind of a cool idea:
    https://www.electricherald.com/tonecap-selector-mod/
    I know it's not a varitone or tonestyler (though I have always been a varitone fan, even though some of the positions are useless, a few give some cool options I think). And I have kind of been drawn to putting something like this in a build.
    Has anyone had experience with a cap switch like this? With so much debate over cap values, would it be useful to have a cap switcher rather than being stuck with one cap? Or just something good for initially choosing the right cap....
     
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  2. Geo

    Geo Friend of Leo's

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    I have a Fender Vibrolux that was modded most likely in the late '70s. It has a variable rotary
    mid range selector with different caps (and think combined with resistors). It was neatly done by
    a company in LA for a fairly known studio musician and producer. Doubt I would use on a guitar
    though but could be a good way to find a likeable taper on a guitar tone control.
    Seems there is a video of a guy using an external one wired to a guitar on youtube.
     
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  3. Steve 78

    Steve 78 Friend of Leo's

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    It would be handy to find the cap value that works best but I wouldn't have it as a permanent mod myself. What I would do is have a switchable RC circuit as a bass cut for the neck pickup.
     
  4. Ronkirn

    Ronkirn Doctor of Teleocity Vendor Member

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    here's something rarely mentioned in these cap and pot discussions and how they impact the tone...

    the actual difference between the "standard" issue in either caps or pots, results in a real useable difference that is relatively subtle... by that I mean take the typical Tele, swap the normal 250 K pot and .047mf cap for what some think of as extreme, 500k and .022mf and most wouldn't notice it as a slap in the face difference... Many wouldn't notice any difference at all..

    Further complicating the issue is, other factors can completely negate any difference heard.. by that I mean, the random tonal contribution that the wood is making, or that of the Bridge, Pickups, the Neck, etc., all are working on the tone at any given moment too, and doing so while the pot and cap are chugging away working too.

    this is why sitting down with pencil, paper and a slide rule (remember those?) and working out the math expecting specific specific sonic results is not possible... such can ONLY move your sound in a generic "direction" toward a sound..

    Think of it as ya wanna go to NYC... ya take whatever route suggested as the best... well, ya may wind up in the Bowery, Harlem, The Bronx, Queens, Lower Manhattan, the Upper East Side... All are most certainly New York City, but all completely different.. The "route" was good, you are certainly in NYC.. but you aren't anywhere near where ya wanted to go...

    Similarly, the “math” may be good, the execution perfect, but ya just don’t sound anything near like what the math said ya would..

    Similarly one can do "all the math" necessary to result in a guitar that makes ya sound like Stevie Ray, and in reality, it comes sounding like Froggie the Gremlin..

    So how do you determine what's best for you.. you try various components until you hit the bull's eye... and that my friends is the ONLY method that actually works…

    And NOTHING sounds “best” except as it pertains to your personal preferences… a 50.00 pot is Not gonna sound better than a 5.00 CTS . . unless you like the resulting sound.. same with the difference between a 3 cent Ceramic cap or a 600 Esoteric Gold Foil PIO…. YOu gotta like it for it to be better than whatever it replaced..

    Another analogy… there’s a meal of a 170.00 Chateaubriand tar-tar.. or a “Whopper”.. if ya hate raw beef and love a Hamburger… ya just saved 165.00 bux.. it’s all in what ya like..

    Now, a well seasoned luthier has a better chance of winding up with the sound you want, but that's simply because after a few thousand guitars, one develops a "sense" as to what will do what to the overall voice... But "you" can negate that.. all you have to do is insist on a list of specific Parts you want to see in your guitar... doing so removes the most effective tool the luthier has to "steer" the sound.. i. e. a choice of what can do what.

    Oh yeah. the cap selector switch is an excellent way to determine what ya like... but ya gotta remember.. having all that "stuff" in the signal path has an effect on the sound too, by virtue of just being there 'in the way"..


    rk
     
  5. Ripthorn

    Ripthorn Tele-Afflicted

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    I built a tele with all controls under the sun. I had 5 different caps, an inductor, and switches to put the caps and inductor in series or parallel, forming low pass, high pass, band pass, and band-stop filters with all kinds of different corner frequencies. It was a bunch of fun calculating out all the necessary component values to get filters in the guitar band and such, but in practice, it really didn't get used much. I also had wiring for series/parallel with the pickups and that was much more usable. Caps tend to have a 20% tolerance, and you have limits where some values can't be discerned from having no cap and others turn the signal to useless mud. Then factor in the fact that in an RC circuit, the product of R and C determines your cutoff frequency, so changing C doesn't mean you are getting new responses that you can't get from a different cap except at the very low frequencies, where things will get muddy anyway. It all adds up to not being worth it in my experience.
     
  6. Binx

    Binx TDPRI Member

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    I agree with rk that the sound you want is unique to what you hear and like. On Brian Wampler's podcast, Chasing Tone, they were talking about how they had always used curly cables to plug in, and one day had to use a magomi or something like that and hated, just because it was a sound they were used to.

    Unique switches on a guitar generally look awesome in my opinion, but I guess there is a reason you dont see a ton of other brands using things like a varitone. With all the options you have between pedals and amp controls, it probably isn't a significantly inspiring mod.

    But as a tool for builds, it might be good to do an external one.
     
  7. SuprHtr

    SuprHtr Tele-Meister

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    I like the ideal of an external box with a rotary switch (or two) to test different cap and resistor values, especially if I'm experimenting with different pickups. It might be worth it if I planned to build many guitars, but for now I'll probably just play with the alligator clips. Building something into the guitar seems unnecessary once you figure out what works well with the pickups.
     
  8. Ronkirn

    Ronkirn Doctor of Teleocity Vendor Member

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    anything placed in the signal path beginning at the pickup and ending with the speaker cone moving erodes the signal from a technical aspect. Nothing added to that signal path can "improve" the "precision" of the generated signal except as it pertains to your preferences.

    "Stuff" placed in the signal path can do only two things..take something away.. or "distort" what is already present..

    that includes anything.. I mean anything like cable (a necessary evil), caps, pots, switches, wire of any kind, all your favorite pedals, and the accumulated crud on the plug ends. Everything leaves its sonic "footprints" all over the signal. then the amp does its thing and sprays it out of the speaker..

    my point is, component myopia is a relevant factor in those engaging any kind of a tone chase, it's best avoided.


    rk
     
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  9. Freeman Keller

    Freeman Keller Tele-Afflicted

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    David Collins at Ann Arbor Guitars has put together a number of videos comparing different electronic components under controlled conditions. They are worth watching (with an open mind). Here is one discussing the results of comparing capacitors with the same values but different dielectric materials (ceramic vs paper in oil "bumblebees")



    Here is the study itself



    David has a number of other vids discussing other components in the signal chain as well as a very good discussion on why the human ear (and brain) hears the things it thinks its hearing.
     
  10. Ronkirn

    Ronkirn Doctor of Teleocity Vendor Member

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    yep. David and I are on the same page... here's another made by an engineer, simply disciussing the quality of different caps...



    This guy doesn't have a "dog in the hunt" as far as guitars go.. its just purely from a electrical engineering aspect... so it's devoid any preconceived notions about tone.. all ya need to know is in the first 5 minutes or so.. but the rest of the video is also quite informative...
     
    Last edited: Sep 20, 2019
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  11. jkingma

    jkingma Super Moderator Staff Member

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    I built a single pickup bass many years ago that really had a short range of tone. I added a mini toggle switch and a second capacitor to cover "the other end of the spectrum" and It work out well enough to justify the effort. But that was just a fix for a problem.

    I wouldn't do this intentionally from scratch.
     
  12. Freeman Keller

    Freeman Keller Tele-Afflicted

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    I happened to be an electrical engineer in a previous life and I agree with both David and this guy. I do find it a bit ironic that people pull out perfectly good ceramic caps from their new les paul and replace them with an old bumblebee from some 1950 radio because "that's what the '59 'bursts had". I also saw bumblebee's on a Gibson web site at 60 bucks each....
     
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  13. Suproman

    Suproman Tele-Meister

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    I have a couple of guitars wired with a 4 position rotary switch instead of a tone pot. I like it, it works well for me but you need to find the right capacitor values for the pickups you are using.

    Using any more than 3 or 4 different caps is overkill in my opinion. I had a Tonestyler once that had about 16 different caps, I couldn't hear the difference between most of the settings.
     
  14. Zepfan

    Zepfan Poster Extraordinaire

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    My avatar guitar came with an extra switch for tone cap switching. It was labeled "R" for usual Rhythm tone cap and "S" for a lower value tone cap for Soloing.

    After putting Firebird/Minibucker combo in it, I took the tone circuit a bit further. I replaced the old 2-way switch with a 3-way on/off/on switch. One side has a .033 cap, the other side has a .022 cap and middle is like having a no-load pot.

    I usually use the .022 and no-load choices the most. The .033 choice is noticeably darker, but not too dark. Some people don't notice the little changes and that may be because of venue size, amps or just the guitar it's installed in. These circuits are more likely noticed at home.
     
  15. LowCaster

    LowCaster Tele-Holic

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    I found interesting that this video is saying to avoid the old PIO, not because of the actual capacitance change over time, but because the paper becomes acidic and that is the cause of current leakage. He says that it is as if there was a resistor in parallel (or bypassing it). I didn’t know that. But what does that do to the tone?

    I know very little about electronics and now I start thinking... would it be a good idea to put a resistor in parallel with the tone cap to replicate those old caps?
     
  16. fasteddie42

    fasteddie42 Tele-Holic

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    I love when RK starts up spit'n truths in a thread.
     
  17. Ronkirn

    Ronkirn Doctor of Teleocity Vendor Member

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    that question is the problem... guys trying to quantify what does what... It doesn't work that way . . it can't work that way, because there are so very many other factors also and always contributing to the voice of the guitar...

    The point with the PIO . . . a cap is supposed to work a certain way.. if it becomes "leaky", it can no longer function correctly, so while that will result in some kind of change, exactly what kind is impossible to predict.. Suffice it to say if a cap is faulty, you do not want it in your guitar.. at least I would think so.. I've never had anyone request a faulty cap in a custom I'm building for 'em.. :p

    Man that would be terrible.. think of the threads discussing how flawed a cap should be to produce the "best" tone... And the ads .. "Our PIO Caps are so faulty. . ." :rolleyes:

    r
     
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  18. Freeman Keller

    Freeman Keller Tele-Afflicted

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    Basically what he is saying in that video is that there are two parts of the way a capacitor functions. The first is that it will bypass frequencies above a certain value (usually to ground but that depends on how it is wired). Th cutoff frequency isn't a hard number (say 5000 hz) the point where it rolls off. The tone potentiometer is a voltage divider that decides how much to roll off (not change the frequency). This is pretty basic freshman 101 RLC circuit theory. The capacitance in farads (or micro farads) determines that frequency working with the inductance of the coil and is determined by the way the cap is built - size and spacing of the "plates", dielectric material.

    Capacitors are supposed to block all the frequencies below that cutoff, most importantly zero hertz, or DC. That allows us to bias various components in an amplifier for example, the grids and plates of tubes, and still pass the frequencies that we are interested in. That is the function of the dielectric material in the cap - the insulator between the "plates". Old caps used paper impregnated with oil and what the guy in the vid is saying is that the insulation can break down and pass the DC. That is less of a problem in a guitar tone circuit but can be a huge problem with the 250 volt DC bias in a tube amplifier. One of his points was that you can measure the capacitance in farads and it is what is marked on the cap (thats what the stripes on the bumblebee signify), but there is some finite resistance (that is what we measure at zero hz).

    So in summary, as Ron said, passive components like capacitors cannot add anything to the signal, it can only remove something. In the normal wiring scheme that is higher frequencies which are removed to ground. The frequency is determined by the capacitance, the type of capacitor determines its suitability for that particular application. What David's video shows is that there is no difference between the types of capacitors as long as they are the same value.

    Back to you, Ron....
     
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  19. Ronkirn

    Ronkirn Doctor of Teleocity Vendor Member

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    that says it superbly ..

    there are many of ya that may find some of the information beyond your scope of interest.. that's not a problem... caps are inexpensive... as are pots... and learning to solder is a good thing...

    just "Hot wire" a couple of leads,, one to ground.. the other to where the original cap was connected to the tone pot... let them hang out of the control cavity... now you can assemble the guitar and just connect cap after cap, trying them until you find what ya like.. No math, no circuit theory, pretty much no thought :D... when ya find what ya like.. open the guitar again, solder it in, close it and ride long and hard into a rockin' future ... you have found your personal sonic panacea..

    and if anyone criticizes your choice, just tell them, "It's there because its what I want dawggonnit..." and that is really the only reason you need for anything you choose to do to your guitar..

    and... remember.. If you can play well, it pretty much doesn't matter a hoot how the guitar sounds (within reason), your talent will completely eclipse any sonic indiscretions the guitar may be guilty of.. and if you cannot play.. its doesn't matter a hoot either... everyone just wants ya to stop making noise. :p

    r
     
  20. 24 track

    24 track Doctor of Teleocity Silver Supporter

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    I built this little dickie to prove exactly what Ron said so eliquently, I used 11 of the common cap values on the A chanel and set up where I could try any other cap I wished to independantly at the same time monitor to ensure the cap was with in reasonable tolerences , also I could select what value pot 250K/500K the caps I used were of different compositions from Bumble bees, PIO, chicklets, tropical fish, Orange drop, ceramic, Mylar, etc and with this arrangement it was brutally appearent that the cap value was more important than the composition , for tone IMHO although this device is overkill it was very exacting in its findings ( Plaus it allowed me to select the values that worked for me and my projects

    P1011396.JPG P1011398.JPG
     
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