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Quick question with Film Capacitor - Polarity

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Per the datasheet, the caps are film and non-polarised. If it were me, I'd check that the caps I'd received were the caps I'd ordered, just to make sure there wasn't some mixup and I'd received polarised caps.

If they're the right ones, the + probably indicates the side with the outer foil. If so, it doesn't matter which way around they go.
 
DaveVoorhis said:
the + probably indicates the side with the outer foil. If so, it doesn't matter which way around they go.
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Well it seems it would work with them either way round in this case, but there is a school of thought which says 'outer foil goes nearest the output'. ;)

(The outer foil thus providing some shielding for the input signal side of the capacitor).
 
Recap all done! Going to update my BOM thread soon. All power board + Tone board + filter caps replaced. Works and sounds fantastic.

Here is an example of what I was using the Kemet Film caps for. Notice the + sign. Pretty sure this was one of the blue water drop looking components (had a plus sign on it too).

SX-650 Power Board GWH-101

C1 and C2: 1uF 25v CSZA

Suggested but out of stock: 667-ECQ-V1H105JL5 1uF 50v

Used: MMK5105K50J02L4BULK

Capture2.PNG Capture.PNG
 
That does appear a polar mark. Is it possible it was tantalum .
Back in the day you'd never be able to get a small film that size in that value. For larger ones you still can't. I'd like to see the pull. There's no harm in installing a film where and elytic was. it generally is an improvement (not necessarily audible).
If i understand the markings it was 1uF @ 25v. I see similar silk screening for 220uf @ 6v on the board. You can clearly get a 1uF in that space. Definitely not a 220uF. It could be a mis print on the silk screening as well. Happens all the time.
 
nj pheonix said:
That does appear a polar mark. Is it possible it was tantalum .
Back in the day you'd never be able to get a small film that size in that value. For larger ones you still can't. I'd like to see the pull. There's no harm in installing a film where and elytic was. it generally is an improvement (not necessarily audible).
If i understand the markings it was 1uF @ 25v. I see similar silk screening for 220uf @ 6v on the board. You can clearly get a 1uF in that space. Definitely not a 220uF. It could be a mis print on the silk screening as well. Happens all the time.
Click to expand...

Here is the post I made with some photos: https://audiokarma.org/forums/index...any-further-suggestions.868114/#post-12728295

BOM Post: https://audiokarma.org/forums/index.php?threads/is-this-a-good-capacitor-bom.868235/#post-12713551

20190511_172526.jpg 20190511_212914.jpg
 
The very small blue eggshaped ones likely were in fact Tantalum. (bottom right, right picture). Likely a line or a dot by one lead of those.
 
Interesting question and good answers that have come up. Watch this videowhere he tests caps on his scope, may want to skip much of it but it shows that they can be polarized. Some I've tested at home don't have any effect but others do.
 
That's been posted before. Changing from tantalum to a film doesn't equally equate to that video. Most films have no polarity. The small difference may be measureable but I tend to doubt audible . Also I imagine few fall into this realm at all. There are plenty of cap threads. So civil some not so much. The last one I remember was by Choffman. It was very good. Sort of off topic in this instance.
 
AnalogueBen said:
Interesting question and good answers that have come up. Watch this videowhere he tests caps on his scope, may want to skip much of it but it shows that they can be polarized. Some I've tested at home don't have any effect but others do.
Click to expand...
The first ten minutes or so are very interesting, while not demonstrating voltage polarity, it does indicate some noise reduction position preference. Once he starts into constructing his test box it quickly degrades into (IMHO) excess complexity. Still, I did learn something new about the lines marked on some caps.
I also must note that the nominal input impedance of a scope plug-in is probably about 1MΩ, much greater than most audio circuit input impedances, so the amplitude of the capacitively coupled 60 Hz signal from his fingers would be much greater than that from a more distant higher frequency noise source into a lower impedance. I think this noise source should be considered as a possible source of difficulty but I am not going to go and check and mark every film cap I come across. Feeding a signal to a tube grid or an op amp input or an FET gate might be of some concern, but not many other places.
 
Glad to know that you gained something from it. Your knowledge of circuitry here appears much broader than mine, so this is why I only used this test method for simpler work such as coupling pairs or when used in crossovers. Best of luck the OP with the recap.
 
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