Tone Cap Polarity Revisited
I’ve been asked a number of times whether the polarity makes any difference when connecting the common guitar tone cap, and I always answer No.
Electrolytic caps are polarized, and can fail or explode if you connect them up backwards. But we don’t use electrolytics for guitar tone – the caps we typically use (polyester film, paper-in-oil, etc) have no significant polarity.
Now, film and foil caps (like Orange Drops and Mallorys) do have an outside foil-wrapping which is used for shielding and is connected on one of the leads of the cap. Ceramic and silver mica caps aren’t built with an outside foil wrap.
Apparently, according to this article by Dirk Wacker in the new issue of Premier Guitar, it may actually make some difference to the sound which way you connect the outside foil of a cap.
I haven’t noticed it myself, but it obviously depends on the guitar, pickups, amp, wire, capacitors, and the ears 🙂
Caps aren’t typically marked for which is the outside foil end- and I don’t know of any way to tell which is which. So, in short, try your tone cap both ways and if you hear that one way sounds better than other, then go for it. If you don’t hear a difference, don’t worry about it!
July 30, 2010 @ 7:03 am
OK. Fascinating.
But what in Jeebas does he mean by “high voltage”!?
I hate unimaginative slang… why not just say what you mean with shorter or fewer words… *sigh*
Does he mean Capacitors manufactured with a High Tolerance? As in, that bit on a Cap where it says blah blah blah 100V or 400V etc.
I have Orange Drop caps, bought before seeing your Crazy Tone Thing and after decidedly decent. They’re marked 400V. Does that mean I need to care what Dirk Wacker said or can I make fun of his name and not care about his informative yet contentious article?
😀 I don’t mean to sound rude towards Mr. Wacker but he seems to of presented me with another potential barrier to get over. I’ve had plenty with all these Guitar shenanigans, I’d appreciate a better thought out answer than “turn around because it might be the wrong way round”. I really don’t see why he couldn’t of thought about the fact that it’s still a fair bit of soldering and that one may have to buy crocodile clip wire connectors of something to test the circuit; all of which will be a waste if it is irrelevant to my current project.
WTf does “”High Voltage”” mean!?
August 4, 2010 @ 3:37 am
I’m totally with you on the skepticism here 🙂 One of the reasons I set out on all these videos, was that I read people claiming that just changing out their brand X pots for brand Y pots miraculously improved their guitar tone. And I just wasn’t comfortable with that 🙂
Re: “high voltage”: If you run too much voltage across a capacitor, the dialectric will break down and short circuit. The voltage rating of the cap tells you at what voltage this will happen.
This is mostly irrelevant for a guitar, since the electronics in a guitar are operating at tiny voltages. 400v rated caps are massively overkill here 🙂
I say “mostly” irrelevant, because I suppose that they manufacture the cap differently to achieve such high voltage ratings, and this different manufacturing technique may change the overall characteristic of the cap, and therefore change the tone…
I still argue that a set of cheap alligator clips should be mandatory in any tinkerer’s tool-box. Just get some! Then it becomes trivial to experiment and try out things like this.
But of course, it also must be said that none of this is really that critical. It’s just a guitar, and it should be fun to play. If you’re happy with the sound, then great. If not, it’s undoubtedly easier to tweak your amp settings or pedals than it is to start tearing down the guitar’s electronics. But, if you like to tinker like me, then go for it 🙂
-John
August 9, 2010 @ 1:54 pm
Thank so very much!
Forgive me if my language was unjust even though abbreviated in one instance.
I think I’ll just consider the Croc clips and dismiss the article as 99% marketing twist in some way or other. My current project is pretty much finished wiring wise but I’m still considering what size cap to use for the Bridge. It’s a Hot Ceramic Mini-HB Rail configuration. I’m using all 500k pots and initially I figured all .047uF caps would be fine but I’m still considering all my options… though I’m 100% on what I’m looking for so I might want to experiment as you have done.
April 7, 2023 @ 4:25 am
The signal from the pickup is AC so please explain how polarity matters. The signal will change polarity 82 times per second if you pick the low E string for example. What am i missing here?
April 7, 2023 @ 11:35 am
I don’t think you’re missing anything. I agree, cap polarity doesn’t matter for guitar tone circuits!