212.42.175.73
In Reply to: Re: RE: CU PIO Reliability Issues posted by gsimon on November 16, 2004 at 02:22:37:
Dear Gilbert,Firstly, if you have experienced this on a lot of our caps you should have sent some back for analysis, I don't remember seeing any from you.
Secondly, these caps only leak oil when the internal seal is broken, this can happen for two reasons,
1.) If the cap is subjected to excessive heat, the oil expands more than the copper case, breaks the seal and the oil starts leaking out.
We stopped using a "hard" seal on the bigger caps about 2 years ago when it became obvious that this was more of a problem than initially envisaged.
2.) The seal is weak to start with and the cap leaks oil almost from the start.
We sell a lot of these caps and the failure rate is fairly minimal, but with any item which is handmade there is always a slightly greater variability in assembly quality and failures do occur as a result.
It is hard to unequivocally guarantee a part like this, simply because it is not possible to ensure that it is always used within its temperature or voltage ratings, but we will exchange caps if we believe that they are at fault without discussion.
If a faulty cap is cut open it is fairly easy to see whether it has been overheated or not.
Hope this explains.
Follow Ups:
Dear Peter,Guilty : I did not send back caps but I will do it.
The caps were used in AN electronics (Kit1 , Pre-Kit , Dac1)
whose components were upgraded but schematics not modified.
Voltage ratings were OK.
Temperature : here is the problem I think.
Yes Kit1 warms , and components have to endure it.
Otherwise you have to advise people the your caps do not endure ClassA Amps.
You say failure rate is minimal ;It is probable but the problem is that this default does not generate a failure but a subtle degrade.
And how many people do open their electronics to verify if there is
some oil on their new caps ?
So I propose to send you back some caps for analysis.
If you can exchange them I am OK ,but only with new model.Greetings
Dear Gilbert,This must have been very early samples of our caps, do you remember how long ago??
(Not an issue as far as exchanging them is concerned, by the way!)
We no longer make the copper foil caps with this type of seal, for exactly this reason, the silver caps on the other hand do not have this problem as they use mylar film not paper in oil.
It is quite true that when the seal breaks the cap's sound deteriorates.
I had severall orders in the last years , all by Philippe (AN France), the last was this summer. But we don't know how long components were on stock .
For example I had some 0,22uF old and new model , and the last order
concerned 0,015uF and I received old models, this value being certainly less demanded than 0,22uF.
I fear I have not keeped them all , so I will return You what remains.
Dear Gilbert,Send me what you have, or give them to Philippe, and I shall collect when I am in Paris next, make sure your details are with the caps and I shall send the replacements directly to you.
This post is made possible by the generous support of people like you and our sponsors: