Need help finding replacement caps for home speakers

[markusm]

I have a pair of Avid 102 speakers made in 1976. While discussing a different issue with my system, someone commented that I should probably replace the caps if they haven't been already. They look to be the original caps and have the following markings:

T.I.(Texas Instruments?)
203
7uf 30VNP (Seems I remember NP is Non Polar)
65 deg. C 7602
Mexico

I don't have a firm grasp of how capacitors are used in various applications, and since I can't find an exact replacement with those values I'm not sure what to go with for an audio application on crossovers. Here's a picture of the cap:

[paulnetv]

Re: Need help finding replacement caps for home speakers

My guess, Search for "Bi-Polar" rather than non polar.

I would think the caps in the PSU are more important than this one but I know next to nothing on audio equipment if I'm honest.

With a quick search on Ebay I just found a number or possible replacements, mainly 10uf and 4.7uf but with more searching I'm sure you'll find something to replace your cap with. Again I am not sure in an audio application that this would work, but it might be worth trying a couple of 3.3uf in parallel if you can't get an exact 7uf match? I'm sure someone more in the know will reply if this is not satisfactory for an audio application such as yours.

[mariushm]

Re: Need help finding replacement caps for home speakers

6.8uF 50v : http://www.digikey.com/product-detai...3-1-ND/4333106

10uF 35v: http://www.digikey.com/product-detai...1187-ND/227628
10uF 50v: http://www.digikey.com/product-detai...1280-ND/228282

Lots more here: http://www.digikey.com/product-searc...=0&pageSize=25

ps. 6.8uF is close enough to 7uF. Alternatively, you could put two regular 15uF capacitors in series (with negative or positive leads tied together) and you get your 7.5uF . Use higher voltage rated caps in this case, let's sa 63v or better.

[markusm]

Re: Need help finding replacement caps for home speakers

My guess, Search for "Bi-Polar" rather than non polar.

I don't need any crazy components in my system. Seriously though, thanks for that... I did see bipolar noted on one of the sites, but didn't realize that was the same as non-polar. I thought it just meant two poles, as in polar.

I would think the caps in the PSU are more important than this one but I know next to nothing on audio equipment if I'm honest.

Well they're not powered speakers so there's no PSU.

[markusm]

Re: Need help finding replacement caps for home speakers

6.8uF 50v : http://www.digikey.com/product-detai...3-1-ND/4333106

10uF 35v: http://www.digikey.com/product-detai...1187-ND/227628
10uF 50v: http://www.digikey.com/product-detai...1280-ND/228282

Lots more here: http://www.digikey.com/product-searc...=0&pageSize=25

ps. 6.8uF is close enough to 7uF. Alternatively, you could put two regular 15uF capacitors in series (with negative or positive leads tied together) and you get your 7.5uF . Use higher voltage rated caps in this case, let's sa 63v or better.

Ok thanks, I wasn't sure if higher voltage or other specs would negatively affect the sound.

As for running them in series, I read a post in another forum that said to never run them in series in speakers, although I don't think he said why, and I have no idea if he's correct in that.

[stj]

Re: Need help finding replacement caps for home speakers

that's a crossover from inside the speaker i think.
so it should be polyester not electrolytic.

[markusm]

Re: Need help finding replacement caps for home speakers

that's a crossover from inside the speaker i think.
so it should be polyester not electrolytic.

Yes it is a crossover... I was looking at a couple of threads on another forum, and people seem to think they're non polar electrolyte caps.

If they're not electrolytes is there even a reason to bother changing them?

*Edit*
I also came across this in a post: "(only electrolytics typically are labeled as non-polar, since for electrolytics that is a special type)"

Is that true?

[stj]

Re: Need help finding replacement caps for home speakers

no, only electrolytics have fluid in them.
a good foto of each end of the cap may be usefull.
if it's a film cap the ends will look the same,
but if it's electrolytic then one end will be welded to the can, the other going through a bung or some resin.

[stj]

Re: Need help finding replacement caps for home speakers

7uf exists.
http://www.rapidonline.com/electroni...acitor-49-9062

not sure if it's not overkill - 600v!

[markusm]

Re: Need help finding replacement caps for home speakers

no, only electrolytics have fluid in them.
a good foto of each end of the cap may be usefull.
if it's a film cap the ends will look the same,
but if it's electrolytic then one end will be welded to the can, the other going through a bung or some resin.

I can upload pics if needed, but each end looks identical. It looks to be sealed by some type of red resin on both ends.

[budm]

Re: Need help finding replacement caps for home speakers

I would upgrade them to Polypropylene: Using two in parallel to get close to 7uF
http://www.parts-express.com/dayton-...citor--027-422

http://www.parts-express.com/dayton-...citor--027-218

The electrolytic you have there probably decreased in the value by now.
Parts-express is a good source for speakers and parts to build your own speakers and X-Over network.

[markusm]

Re: Need help finding replacement caps for home speakers

I would upgrade them to Polypropylene: Using two in parallel to get close to 7uF
http://www.parts-express.com/dayton-...citor--027-422

http://www.parts-express.com/dayton-...citor--027-218

The electrolytic you have there probably decreased in the value by now.
Parts-express is a good source for speakers and parts to build your own speakers and X-Over network.

So you agree that it's an electrolytic? stj's comments have gotten me confused as to whether it is or not...

As far as running them in parallel... How do you go about that? Should I solder the 1st cap into the board and then solder the second cap to the leads of the 1st cap?

[markusm]

Re: Need help finding replacement caps for home speakers

Someone on another forum identified it as an old Callins wax seal electrolytic capacitor.

[budm]

Re: Need help finding replacement caps for home speakers

"So you agree that it's an electrolytic?" Yes, that is why it has + on the ends of the caps, internally there are two caps are connected in series with - tied together to form non-polarized cap.

Parallel, series connection of the capacitor.
http://www.engineeringtoolbox.com/ca...es-d_1388.html

[markusm]

Re: Need help finding replacement caps for home speakers

"So you agree that it's an electrolytic?" Yes, that is why it has + on the ends of the caps, internally there are two caps are connected in series with - tied together to form non-polarized cap.

Ah ok... I wondered why they put a + on both ends since it already said NP.

Parallel, series connection of the capacitor.
http://www.engineeringtoolbox.com/ca...es-d_1388.html

Thanks, but I already know parallel vs serial... I was just asking how to go about doing it. I guess I should solder one cap in place, and then solder the leads of the second cap to the 1st?

[stj]

Re: Need help finding replacement caps for home speakers

why not find a 6.8uf cap?

[markusm]

Re: Need help finding replacement caps for home speakers

why not find a 6.8uf cap?

Well, that's what I planned on doing. But after finding some threads on another forum, I've noticed most people seem to go with running 2 in parallel to get the same rating.

Is that a waste of time if I'm only .2 off?

Also if I do run them in parallel, since the poly caps are so much bigger, I figured on the soldering part I'd just the leads together and solder them to the pads on the back side of the PCB.

[stj]

Re: Need help finding replacement caps for home speakers

interesting point - what is the distance in mm between the 2 holes for that cap?

[markusm]

Re: Need help finding replacement caps for home speakers

I'll have to pull the crossovers back out to check when I have a chance, but if you're referring to my comment about them being bigger, I'm more concerned about the height as a bigger diameter cap would probably not fit under the spade connectors going to the fuze.

[stj]

Re: Need help finding replacement caps for home speakers

that'a a valid point.
polyester boxes are pretty tall

can you relocate the pcb away from the holder?