Correct tone capacitor

[bongostealth]

I just installed a ceramic .047uF capacitor in a tone control in my bass. Is this a good capacitor? I know the guys at BestBassGear.com use .047mfd capacitors. I got mine at Radio Shack and they don't have the "mdf" kind. Just the uF. Is there much of a difference?

I don't know much about capacitors, or any other electronic components for that matter.

 

[ArtechnikA]

µF (microFarad) == mFd (microFarad).

Same thing. Some people use the real Greek-letter 'mu' (µ), some substitute lowercase 'u', and some use mFd for microFarad. All the same. You're fine.

 

[FunkMetalBass]

µF (microFarad) == mFd (microFarad).

Same thing. Some people use the real Greek-letter 'mu' (µ), some substitute lowercase 'u', and some use mFd for microFarad. All the same. You're fine.

This.

Man does it frustrate me when they use the "m", though. Granted, context is usually enough to get you through a schematic that does it, but if you're not paying attention and just blindly going through the conversions (especially a schematic that chooses to keep everything in microFarads instead of switching to nanoFarads or picoFarads), you could end up with a .001mF=1uF cap instead of the 0.001uF=1nF=1000pF cap that you should have gotten.

 

[line6man]

This.

Man does it frustrate me when they use the "m", though. Granted, context is usually enough to get you through a schematic that does it, but if you're not paying attention and just blindly going through the conversions (especially a schematic that chooses to keep everything in microFarads instead of switching to nanoFarads or picoFarads), you could end up with a .001mF=1uF cap instead of the 0.001uF=1nF=1000pF cap that you should have gotten.

I'm not sure where we got "mFd" from. A lowercase u works perfectly fine, in place of the proper Greek letter, Mu, but to make things confusing with the same prefix that denotes milliFarads? It's madness!

 

[SGD Lutherie]

I'm not sure where we got "mFd" from.

Older caps had MFD on them, probably because what ever they were using to print on the caps didn't have the µ character. It also wasn't widely written that way. I always saw it as "microfarad" or MFD.

The Wikipedia article on Farad states:

"Values of capacitors are usually specified in ranges of farads (F), millifarads (mF), microfarads (μF, or MFD in industrial use), nanofarads (nF) or picofarads (pF).[1]"

And: "In texts prior to 1960, mf rather than the modern µF frequently represented microfarads. Similarly, mmf represented picofarads."

1960 is when the International Bureau of Weights and Measures standardized it.

So "MFD" is correct usage in industrial fields, i.e., cap manufacturing. It's an abbreviation.

This chart:

http://www.justradios.com/uFnFpF.html

Also shows MMFD for pF.

 

[Aceonbass]

Ceramic caps can be microphonic, and caps from Radio Shack aren't that good to begin with. I use Cornell-Dubillier & Roederstein caps(metalized polyester I believe) as well as vintage Ajax Blue caps (paper in oil) when I can find them. Never go cheap on your bass's electronics. Even though I usually don't have more than a couple bucks in a cap, it doesn't take much, and it's way better than Radio Shack.

 

[SGD Lutherie]

Radio Shack sells perfectly fine polyester film capacitors. For the application of a tone control, they do exactly what they are supposed to do. They are 10% tolerance, but that shouldn't matter.

Why would you use a vintage paper in oil cap? What benefit do you think it has over any other cap, and even a ceramic?

The other thing about tone control caps in a passive instrument is the cap has very little affect on the tone until you have the control very close to zero. between 10 and maybe 4, you are heaving the resistance of the pot loading the pickup. The reason for this is the impedance of the capacitor in the range of the resonance is a less than the pot value, so it appears as a plain piece of wire. As the pot gets near zero the cap is more important.

But pretty much caps are caps when used in this context.

 

[Aceonbass]

Most of my basses, and the basses and guitars I've worked on have been fairly expensive instruments. While I don't subscribe to the snake oil that modern vintage repop tone caps at $20-$30 each are a noticeable improvement, I can't in good conscience put a fifteen cent cap in one of these instruments. A lot of the wiring I've done has been on vintage Rickenbacker instruments where sourcing original brand components was a priority. Hence the Ajax caps. In some cases, I have been able to tell the difference between different tone caps of the same value, as have the guys who I've learned from say they can.

 

[SGD Lutherie]

But caps are a 15 cent part. It doesn't matter the price of the instrument. Why pay for an over priced cap that is functionally the exact same thing.

If you hear a difference in tone at the same value, it's not the same value as what's marked. You have to measure the cap with a meter.

Personally I like these caps:

 

[Pimmsley]

I went down from a .1uF to .047uF metal poly when upgrading the pots in my CV Squier 50's P and got some extra edge back on flats when the tone is rolled off... I like that value cap.
I just bought a bag of 5 wima caps from Radio Spares for about $4.00 delivered to use on upgrades.

 

[Aceonbass]

I use a multi-meter to check my parts against their rated values before I build anything. I get my C&D caps, as well as most of my caps from Mouser, and find that they're within 5% of rated value even though they're 10% caps. Although it may not be something you can measure, I do hear a difference between tone caps sometimes.

 

[iiipopes]

I like Sprague orange drops because they are consistent in their manufacturing, relatively inexpensive, easy to work with, and easy to source in my preferred tone cap value of .033 microfarad.

Tonally? No more than a capacitor does in an electric bass or guitar circuit, the advantages of esoteric materials, higher voltage and heat ratings, or the disadvantage of microphonics just aren't there.