Are film capacitors directional?

Thanks, Al! Very helpful. I bought a better meter today, so I will try the procedure you described tomorrow and report back.

Bryon

Thanks Rodman. I don't have an oscilloscope. Any other way to measure?

Bryon

Thank you, Al. My multimeter doesn't go to AC millivolts. I will borrow a better meter from a friend. Please forgive my ignorance, but once I have the meter, what exactly do I do?

bc

Okay, Al, I think I'm following your instructions exactly, but I'm not getting consistent results. I've tried several different capacitors, and I get a different reading every time. Don't know what I'm doing wrong...

-I checked the outlet and it is definitely grounded.
-I've drained the capacitors by connecting a wire between the two leads and then taken readings.
-I'm using clips to ensure that I have a good connection.
-I've draped power cords from 2 different devices over the caps.

...and still I get constantly changing results. Some of the time, the meter WILL come to rest on a specific number. But when I remove the meter's leads and check again, the number is different. Sometimes the number is positive, sometimes negative, even for the SAME end of a cap. I'm confused. Any ideas?

Bryon

Are you using a setting for AC (not DC) volts? Not sure how you could sometimes be getting a negative number for AC volts.

I had it set for DC. My only defense to the charge of idiocy is that the meter is new to me as of yesterday, and I accidentally threw away the instructions with the packaging, and the manufacturer's website has been down all day. Even so, I find myself guilty as charged. I am an idiot.

The meter is a Gardner Bender GDT 3190. I don't think it's sensitive enough to perform this test. So I need to go out and buy another meter. For the love of...

bc

Hi Al,

I borrowed a Fluke 115 from a friend. Here is the owner's manual. I tried the procedure again, and again I got confusing results. I think I should seek medical assistance for a severe multimeter learning disability.

At the risk of testing your considerable patience, can you try to walk me through this?

Bryon

Since Al's valiant effort to help me determine the directionality of these caps has failed to produce an answer, I emailed Parts Connexion, who sold me the Mundorf caps. They said this...

Regarding the caps...while caps aren't polarized.....some people "feel" they sound better, if the outer foil is connected to the INPUT side....and the input side is on the left, when reading the case printing from left to right.

.

But this seems to contradict what I read on the auricap website, which said...

The idea is to always have the outside foil connected to the lower impedance to provide outside foil shielding to noise. Circuit OUTPUTS are always lower impedance than inputs and should be connected to the outside foil.

So does the outer foil connect to the INPUT or the OUTPUT?

You can see a picture of the crossover I'm building, prior to soldering, here. The + outputs, which haven't been added yet, are marked "OUT" in red. Assuming the outer foil is connected to the LEFT lead of each Mundorf cap in the photo, do I have the caps oriented correctly?

Thanks,
Bryon

Thanks guys.

R2 = 10W 3.3Ω
R4= 5W 3.9Ω

bc

Thanks, Al!!