finding rare capacitors

[corndog]

hi,

I have been wanting too replace the capacitor's in my beovox3800 crossover's for a while but i have not found anwhere i can get the correct capacitors

what i'm after are:
4 25v 40micro farad
2 50v 4.7 micro farad

the only ones that i have found that i thought might work are motor start capacitors which are much larger. does anyone have any clues where i could buy some in the uk or elsewhere?

i really appreciate any help because i'm really not that familiar with finding electronic's components. Thank you.

 

[cr0sh]

Are these electrolytic caps? The 40 uF sounds strange; the closest you are likely to find is a 47 uF - as far as the voltage is concerned, use a cap that is rated at or above that voltage, and it should work fine (higher voltage caps are typically physically bigger than lower voltage ones, so keep that in mind when replacing them).

You should be able to find such caps (47 uF and 4.7 uF) fairly easily - for instance, this source (in the US):

**broken link removed**

Has them; for the UK, I would think RS, Farnell, etc - would stock these values as well (then there is Mouser and Digikey, which will have them)...

 

[corndog]

thanks! i checked out farnell about a year back but that was for the 40uF. I'll give those a shot. thanks again

 

[Nigel Goodwin]

Why do you want to replace them?, it's VERY, VERY rare for crossover capacitors to fail.

 

[corndog]

There was a thread a while back on beocentral forum where a guy with the same speakers had his fail and he explained that it was the high end sounds that suffered. I dunno how bad his were but mine do not sound as good as they should considering they are seen as ok speakers. They are 30 years old so they may need replaced? I just hope i can improve them by replacing the caps.

 

[cr0sh]

The next "standard" value down from 47 uF is 33 uf, so you might also pick that value up too, and see which make it sound "better" (both are equally as far away from 40 uF)...

 

[bryan]

If the speakers are 30 years old it's more likely the speakers themselves are just plain worn out.

 

[corndog]

they might be but they don't even look that used. the 12 inch bass speakers are fine so if it meant getting new tweeters and midrange at some point i might try that. I found some on farnell that are a high voltage but small and cheapish. thanks for everyones input.

 

[tvtech]

Crossover Network...Likely Non polarised...

To solve your first question:

25v 40micro farad. Take two 100micro farad 25V or higher caps. Solder the Negatives together. Cut off the soldered Negatives (after the solder). Plug the remaining two Positives back in and Solder them back onto the board. That gives you one Bipolar cap that will read around 50micro farad and should handle @ least 25V.

50v 4.7 micro farad. Take two 10micro farad 50V or higher caps. Solder the Negatives together. Cut off the soldered Negatives (after the solder). Plug the remaining two Positives back in and Solder them back onto the board. That gives you one Bipolar cap that will read around 5micro farad and should handle @ least 50V.

You should be good to go

Cheers

 

[corndog]

thanks! that is great because they are actually bipolar capacitors. i ommited that before because i thought that would be standard. yesh i should finally be able to fix these beasts up. Thank you.