Replacing capacitors

[mrmodify]

Dumb question.

On older recievers is there any benefit of going through the reciever and replacing all the capacitors?

I ask because I have read on a audio sight of people going through older recievers and replacing all the capacitors.

 

[CocaCola]

Yes, caps (electrolytic capacitor) have a short life span and are failing from the minute you purchase the device, and thus replacing them as they age is a good (necessary) thing...

 

[(*steve*)]

However some types of capacitors have long lives and do not need to be replaced.

waxed paper capacitors are the worst (from the 1940's)

Very old electrolytic capacitors (any in bare metal cans) or any that show bulging and leakage are next worst.

For anything else, define "older". If it's under 20 years old then many of the other electrolytics will probably be OK (especially those not under stress).

 

[mrmodify]

Thanks for the replies, The recievers are from the 70's

 

[davenn]

Thanks for the replies, The recievers are from the 70's

well the electro's are 40 odd years old then are a good change some or most of them are drying out

other caps like disc ceramics, polyester, polystyrene etc have a very long life span in comparison

cheers
Dave

 

[mrmodify]

A dumb question. Does the capacatance change when dried out?

 

[(*steve*)]

Less than you might think...

Equivalent series resistance tends to change earlier and more. For those parts of the circuit where that is important (perhaps none in a receiver of this age) you get the first symptoms of failure.

By tht time the capacitance has changed so much that circuit performance is drastically altered, the capacitor is a lonnnng way past it's use-by date.

 

[mrmodify]

A great thanks to all, will go through and see what I will need and order the caps.

This is a great site!! I commend all that are involved.