Cap Question or Help Me, DVM, Your My Only Hope

[marnold]

Cap Question or Help Me, DVM, You're My Only Hope

I'm pondering this upgrade to my Charvel Tele. Since I will be gutting the electronics, I will need new caps for the tone pot (assuming I decide to put a tone pot back in) and for the Jerry Donahue mod. Is .047 the "standard" cap for a Tele/single coil tone control? Are the caps available at my local Radio Shack good enough for the project or would I be better off ordering them some place else?

 

[tot_Ou_tard]

You had me cracking up that title Princess Marnold!


Darth Voodoo?

 

[Spudman]

Darth Voodoo, Spud Vader, Tonebewankanobi, tOt the Hut, Princess Marnold, Carpc3po...where the heck am I?

 

[duhvoodooman]

Darth Voodoo?

That's Obi Wan Duhvoodoo, unless I go over to the Dark Side and start charging $300+ for my ZYS's...

Marnold, re: your question, the cap size most often associated with single coils is 0.022uf. It's really tied to the pot resistance that you use. Single coil guitars generally use 250K pots, and 0.022uf caps will maintain a nice bright tone, while 0.047 will filter filter out more high end and darken the tone. For the 500K pots used in most humbucker guitars, the 0.047's are about optimal and 0.022's will usually sound too bright. But there are no absolute "rules" and it depends upon the sound you're trying to achieve.

I'd recommend a decent quality polyester film cap. If your local RS carries them, fine. Otherwise I'd order them from someplace like Small Bear Electronics, who carry a nice assortment. FYI, many people consider Sprague Orange Drops to be the ne plus ultra of film caps (do you have any idea how long I've been waiting to use the term "ne plus ultra"??). They'll run you somewhere around $0.50 - $0.80 apiece, depending upon capacitance rating. I'd get a few .022's and a couple of 0.047's to have on hand for humbuckers. I'd stay away from ceramic caps, as they have a reputation for sounding somewhat harsh or grainy.

 

[marnold]

Thanks for the info, DVM. Well, I ran to the local RS and they have precious few caps in stock--none of the right size or type. Looks like I'll have to do some more planning before I do this.

Most places I've seen have the cap values reversed from what you said, .047 for single coil and .022 for humbuckers, viz Guitar Fetish.

Any more "princess" cracks and I might have to relocate a certain pointy headstock, if you get my drift

 

[Tone2TheBone]

Darth Voodoo, Spud Vader, Tonebewankanobi, tOt the Hut, Princess Marnold, Carpc3po...where the heck am I?

Tonebewankanobi......LMAO :R

 

[duhvoodooman]

I've seen this both ways. Some people say a Fender is too bright with .022's and some say a humbucker is too dark with .047's. Others say Fenders are supposed to be bright and 'bucker's should sound dark. That's what I mean about it being a matter of taste, and why it's a smart idea to have some of both sizes on hand. Go with what sounds best to you....

 

[Plank_Spanker]

When I modded my Strat, I went as far as to solder wires to the pots with alligator clip leads to clip on different caps and try them while I played.

The .022 cap sounded best to me with this particular guitar, but your mileage may vary.

 

[marnold]

When I modded my Strat, I went as far as to solder wires to the pots with alligator clip leads to clip on different caps and try them while I played.

The .022 cap sounded best to me with this particular guitar, but your mileage may vary.

Cool idea--I might just try that. I'm getting really itchy to start doing some of this, but I promised myself that I wouldn't buy anything beyond necessities until we get the credit cards paid off. So the bad news is that you'll probably get a bunch more stupid questions about this between now and then

In dealing with caps, using the English "u" to represent the Greek "mu" μ which is short for "micro" really throws me off. I studied (biblical/koine) Greek for seven years. It would make more sense to me to use mF than uF, although I understand why it's done.

 

[ShortBuSX]

Here is a nice supply of guitar specific caps: http://www.singlecoil.com/shop.html

 

[ShortBuSX]

I'd recommend a decent quality polyester film cap. If your local RS carries them, fine. Otherwise I'd order them from someplace like Small Bear Electronics, who carry a nice assortment.

But why such high voltage caps? 600v???

 

[duhvoodooman]

I guess 'cuz they use 'em in amps, too, where 400 - 500V DC is pretty commonly encountered.

 

[ShortBuSX]

So theres no issue of using a higher voltage cap as opposed to a lower 100v cap?

Would a 600v cap be much larger? Ive got a small control cavity(no pickguard) so size and space are an issue...but would like to experiment with caps(possibly with a set up like Plank Spankers).

 

[duhvoodooman]

So theres no issue of using a higher voltage cap as opposed to a lower 100v cap?

Would a 600v cap be much larger? Ive got a small control cavity(no pickguard) so size and space are an issue...but would like to experiment with caps(possibly with a set up like Plank Spankers).

They'll work fine. The only potential issue is the one you mentioned--size. 600V caps will certainly be larger than 100V's. If the cap's physical dimensions aren't listed, try it looking up on one of the big electronic component websites, like Mouser or DigiKey. They pretty much always have dimensional data....

 

[ShortBuSX]

try it looking up on one of the big electronic component websites, like Mouser or DigiKey. They pretty much always have dimensional data....

I keep going back to that Mouser site...very easy to find EXACTLY what you want.(you just gotta know what values you want). So thank you for your previous link to Mouser!

What about same cap values...but differnt materials? Like there are about 5 differnt "Poly" type caps such as polyester, polystyrene or polypropylene...or mica and ceramic...are there any tonal differences between materials as with values?

 

[duhvoodooman]

I keep going back to that Mouser site...very easy to find EXACTLY what you want.(you just gotta know what values you want). So thank you for your previous link to Mouser!

Yeah, Mouser's pretty amazing. It can be overwhelming with the sheer volume of stuff, but they have pretty much everything under the sun there! Helps to have their catalog, too. Often quicker to find stuff in that, if you don't know exaclty what you want.

What about same cap values...but differnt materials? Like there are about 5 differnt "Poly" type caps such as polyester, polystyrene or polypropylene...or mica and ceramic...are there any tonal differences between materials as with values?

Wow, this answer could stretch on for pages! You're better off Googling around and reading several references on capacitor types used in guitars and audio applications. Suffice it to say that the different types have their uses, based upon voltage and current requirements, capacitance ratings, temperature limits, and many other factors. In general, you're probably going to be best off with polyester (cheaper) or polypropylene (more expensive) film or metal film types. Tighter tolerances (e.g. 5% vs. 10 or 20%) will be more expensive but give more consistent & predictable performance. Ceramics tend to be electrically noisy and sharper in sound, and micas are usually only used for very low capacitance values. Electrolytics are noisy, also, and usually high in capacitance rating. Most of them are polarized, too, which means that they can explode if installed backwards. I avoid them whenever possible.

Keep an eye out on the capacitance ratings, 'cuz it can be confusing. Most are rated in either microfarads (uf) or picofarads (pf). 1 uf = 1,000,000 pf, so there's a HUGE difference between the two! Make sure you're getting the correct rating.

 

[ShortBuSX]

Wow, this answer could stretch on for pages! You're better off Googling around and reading several references on capacitor types used in guitars and audio applications.

The best reference Ive found so far has been http://www.diyguitarist.com/ ...click on the "MISC" tab at the top of the page and then "Capacitor Field Guide" is what you wanna read...Id give a better link or cut and paste if it were an option...but none the less very informative!

Keep an eye out on the capacitance ratings, 'cuz it can be confusing. Most are rated in either microfarads (uf) or picofarads (pf). 1 uf = 1,000,000 pf, so there's a HUGE difference between the two! Make sure you're getting the correct rating.

Yeah Ive been checking and double checking before ordering, and Im still getting all my questions out before I install what Ive got(from Mouser)...and Im likely to try something different again soon cause caps are sooo damn cheap even the low tolerances.

Okay back to volts...are there any advantages or disadvantages to using higher or lower volt caps? Like higher volts giving the ocassional tinker'er a heavier jolt while working on his controls than a lower volt cap?

Also the previously mentioned article keeps mentioning temperatures and performance...Im not good with Celsious, so theres my confusion...but is there any kinda real world temp issues with caps in guitars? Remember I live in Florida.

Sorry for all the cap questions...Im really just trying to grasp more of what Im doing...Im good with just about everything, except electronics where numbers are concerned.

 

[duhvoodooman]

Electric guitar controls applications are about the mildest use conditions conceivable--tiny voltages & currents, room temperature, etc. So don't sweat that stuff. Re: voltage ratings, as I said previously, the only real impact is physical size--higher V ratings, bigger caps (assuming you're staying within the same type). No, you don't have to worry about shocks. Electric guitar pickups generate tiny currents and voltages. That's why you need an amp!

 

[ShortBuSX]

Yeah, I just know caps store energy and just wanted to make sure I wouldnt take on 600v trying to swap out caps while chasing tone.

 

[marnold]

Just to resurrect this thread slightly, on the Telecaster forums I found a link to this capacitor test where ceramic, polyester film, and paper in oil caps were tested both by switching through them and listening and also on a meter. Cool stuff. Basically, the differences are there but they are very minor. Thankfully caps are cheap so you're not talking about a ton of cash either way. It sounds like the differences could be far greater in a situation where more "juice" is applied, viz, an ampf.