ANK AudioKits support forum
Well chaps, roughly two years ago, I took the plunge, and invested in Audionote silver wire and CU PIO's for a SE amp (Audionote U.K.). Results were superb.
And having tried many different types of caps, the Audionotes sang sweet music every time.
However two years down the line their leaking like the proverbial Queen Mary, impedence measures, 96K across the leads, not in the least inspiring, especially when there's a rather fine Lowther DX4 on the other end! (Whoaa-D.C., fry those coils)
Anybody else's CU PIO's suffered the same fate?
There are 2 production series of pio caps with copper housing :
- old model : sides with hard and polished material
- new model : sides rubber covered , smaller size
The new model is OK.
The old sounds good at the beginning but after a time ,
it suffers form oil leak (like venerable british bikes) and the sound
degrades . I have verified it on a lot of caps !
Alas ther are still old models in Audio-Note shops.
I would strongly advise to verify , if you buy some , that they are
new models. The old should go to garbage can.
I got 4x old version Copper tube PIO 0.22u/630V from DIY HiFi Supply in Hong Kong for my kit 1 two years ago. One of them was down a month ago and now I know what the problem is. Can I send them back to you or DIY HiFi supply for analysis and replace for the new version ?
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.
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.
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.
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.
Are your copper foil PIO's the older Jensen-made caps with the "Audio Note" logo, or are they the new Audio Note caps with the copper tube housing/body?
Thank you for taking an interest. They are not the Jenson CU PIO's, they are Audionotes own branded copper tubed versions.
Does make me wonder just how many amps are on the verge of going bang, especially if there is a noted problem with reliability.
And lets not forget the financial investment involved!
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