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I'm doing a cap replacement on 4 wharfedale airedale sp speaker crossovers.I would like to change all the caps with film caps.there are 7 caps per board and I don't want to go broke or over spend on the quality.I hope you can give me a little guidance and tell me if I should change the resistors as well. thank you for any help. Scott
If the capacitors don't have a voltage "NP" after the capacitance, they are not electrolytic capacitors. electrolytics are aluminum bottles, filled with aluminum foil etched by chemical slime. the water in the slime evaporates through the elastomeric seal. There were two brands of epoxy sealed caps that did not leak, and the only consumer product known to contain one of them was the Fender amp with green CDE caps of the seventies.
Plastic film caps except for certain notorious early brands, do not deteriorate. One such brand made in France about 1966 was SCR.
Resistors involve no water, no rubber seal, and unless overheated, do not deteriorate. Carbon composition resistors that were not paint sealed against moisture would deteriorate from moisture. The production of these stopped about 1980. The paint became common in the AB & Sprague carbon comp resistors used in the US in premium brands (HH Scott, dynaco) after 1960.
The voltage that you need to have caps rated at depend on the watts rating of the speakers and the amplifier. Amps smaller than 600 w/ch typically produce less than 100 volts, and caps rated at 100 volts is adequate. Most homeowners have amps rated <100 w/ch or 28 v.
From parts-express I'm buying film caps made by "dayton" which is parts-express, and audin. Few speaker sized capacitors are stocked at general electronics parts distributors. The caps commonly stocked at parts-express are 250 vac rated. This doesn't hurt but makes them very big. Outside the USA do not use parts-express. The most non-distorting plastic for caps, according to John Curl, is polyprophylene. Polyester caps will work, but not be as sonically transparent.
Plastic film caps except for certain notorious early brands, do not deteriorate. One such brand made in France about 1966 was SCR.
Resistors involve no water, no rubber seal, and unless overheated, do not deteriorate. Carbon composition resistors that were not paint sealed against moisture would deteriorate from moisture. The production of these stopped about 1980. The paint became common in the AB & Sprague carbon comp resistors used in the US in premium brands (HH Scott, dynaco) after 1960.
The voltage that you need to have caps rated at depend on the watts rating of the speakers and the amplifier. Amps smaller than 600 w/ch typically produce less than 100 volts, and caps rated at 100 volts is adequate. Most homeowners have amps rated <100 w/ch or 28 v.
From parts-express I'm buying film caps made by "dayton" which is parts-express, and audin. Few speaker sized capacitors are stocked at general electronics parts distributors. The caps commonly stocked at parts-express are 250 vac rated. This doesn't hurt but makes them very big. Outside the USA do not use parts-express. The most non-distorting plastic for caps, according to John Curl, is polyprophylene. Polyester caps will work, but not be as sonically transparent.
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Hi Scott!
The capacitors fitted are ELCAP bipolar electrolytic capacitors (as in attached image).
These do not age well and should be replaced as a matter of course.
To preserve the original character of the loudspeakers, you may wish to consider replacing them with modern bipolar (NP) electrolytic capacitors like the ones linked to here: Mundorf Electrolytic ECap Capacitors
Fitting seven, much larger film capacitors onto the crossover board may be problematical, so check their dimensions carefully before ordering film types.
The capacitors fitted are ELCAP bipolar electrolytic capacitors (as in attached image).
These do not age well and should be replaced as a matter of course.
To preserve the original character of the loudspeakers, you may wish to consider replacing them with modern bipolar (NP) electrolytic capacitors like the ones linked to here: Mundorf Electrolytic ECap Capacitors
Fitting seven, much larger film capacitors onto the crossover board may be problematical, so check their dimensions carefully before ordering film types.
Attachments
Dayton Audio make more values of capacitors so you can get closer matches. Also film capacitors would be better choices where they are affordable and there's space to fit them. Here's a 6.2µF film cap that's quite cheap:
Dayton Audio DMPC-6.2 6.2uF 250V Polypropylene Capacitor
Dayton Audio DMPC-6.2 6.2uF 250V Polypropylene Capacitor
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completed crossover picture
My curiosity is piqued!
May I ask how you were lucky enough to come by four Wharfedale Airedale speakers?
An externally hosted image should be here but it was not working when we last tested it.
May I ask how you were lucky enough to come by four Wharfedale Airedale speakers?
these are airdale sp speakers
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Imgur: The magic of the Internet
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