Audionote copper mylar in oil failed

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Hi guys..

I just want to share my experience with Audionote copper mylar in oil caps.

I built 300B SE amp base on Audionote Quest but modificated to stereo amp instead of monoblok amp. I used Audionote caps 0.33 uF/630v copper mylar in oil (copper tube, black label not white and diameter bigger than current Audionote caps). I bought 1 pair from Partsconnexion Canada (they are a nice seller doh) about 1 years ago and just 6 months ago I finished the project and started to fire up the amp and sounds very lovely.

2 days ago I turned the amp and playing some vocal music, everything seems going ok until 2 hours during playing some slow music sudently I heard very bad distortion on my left loudspeaker and the volume seems decrease. I smelled bit burnt odour near the cathode resistor (it's very hot on that resistor). I hurry up turn off the amp, get my multimeter and checked everything until I found that the Audionote coupling cap was shorted and pass through 271vDC!!

Maybe you guys ever have experienced fail caps as I did? I've sent complaint to Audionote contact via email and haven't any reply until 2 days maybe they too busy :(
I questioned them about the quality control and cap durability or maybe I just unlucky hehe.....I never experience any problem with other cap I use until now (I also use Jensen copper in oil, Mundorf Silver Oil, Supreme, Dynamicaps, Jantzen Silver, etc)

For now I doubt to use Audionote cap again, maybe I will try Jensen paper tube instead buy again AN caps

cheers....
Erik
 
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I wonder if EU waste disposal and recycling regulations were the real reason for the use of vegetable oil

mmmmmhhhh, let's put it into numbers.
EU has 260000000 cars
(260 Million)
which require a 6 liter oil change twice a Year, so the EU has to dispose of:
3072000000 liters (3072 Million liters) which @ 0.85Kg/l weigh over 2.6 Million TONS.

I guess that compared to that, a couple spoonfuls of oil aren't significative, so I think that poorly performing vegetable oil (if it was actually used of course) was chosen for publicity/"exotic/esoteric component" commercial reasons.
 
No, that's being logical. The EU frequently applies regulations in a completely unbalanced way and I could easily see them wanting a recovery plan for each capacitor.
Used engine oil is supposed to be disposed in special tanks anyway, you are not allowed to just dump it
 
I would indeed bet real money they used recycled vegetable oil..........not any such "Extra Pure Olive-Oil". If the filtering process was not absolute......micro sized particles of someones long since cooked milanesas, wound up into the cap it probably was a source of shorting out.
Using organic matter in such products is silly & quite likely a marketing ploy.



___________________________________________________Rick........
 
Oils Ain't Oils....

Soybean oil is normal for modern industrial capacitors.
I don't know what the additives are, but they make the oil red coloured, thick, gooey and it stinks....really bad.
In the old days industrial capacitors used some kind of oil with PCB additive to inhibit moisture ingress...PCB's are now banned and are a declared toxic waste :eek:
Be aware that caps in old tube gear may contain PCB's.....modern caps should have markings saying 'PCB free'.
Yush? disease - Wikipedia, the free encyclopedia
Appropriate vegetable oils which may be applied in the oil mixture of the present invention are selected from sunflower seed oil, rapeseed oil, soybean oil, castor oil and maize or corn oil.

http://www.gits.kmutnb.ac.th/ethesis/data/4710185069.pdf
Each capacitor is filled with our patented, environmentally-friendly ESO (Epoxidized Soybean Oil). Used as the dielectric fluid, the soybean oil protects metallized film from corrosion, aids optimum heat transfer, and helps suppress the degrading effects of corona, which may otherwise cause premature failures. Proprietary processing with vacuum and heat cycles ensures complete removal of moisture, resulting in superior capacitance stability and long term reliability.

Aerovox Capacitor Specifications


Dan.
 
Hi guys..

I just want to share my experience with Audionote copper mylar in oil caps.

I built 300B SE amp base on Audionote Quest but modificated to stereo amp instead of monoblok amp. I used Audionote caps 0.33 uF/630v copper mylar in oil (copper tube, black label not white and diameter bigger than current Audionote caps). I bought 1 pair from Partsconnexion Canada (they are a nice seller doh) about 1 years ago and just 6 months ago I finished the project and started to fire up the amp and sounds very lovely.

2 days ago I turned the amp and playing some vocal music, everything seems going ok until 2 hours during playing some slow music sudently I heard very bad distortion on my left loudspeaker and the volume seems decrease. I smelled bit burnt odour near the cathode resistor (it's very hot on that resistor). I hurry up turn off the amp, get my multimeter and checked everything until I found that the Audionote coupling cap was shorted and pass through 271vDC!!

Maybe you guys ever have experienced fail caps as I did? I've sent complaint to Audionote contact via email and haven't any reply until 2 days maybe they too busy :(
I questioned them about the quality control and cap durability or maybe I just unlucky hehe.....I never experience any problem with other cap I use until now (I also use Jensen copper in oil, Mundorf Silver Oil, Supreme, Dynamicaps, Jantzen Silver, etc)

For now I doubt to use Audionote cap again, maybe I will try Jensen paper tube instead buy again AN caps

cheers....
Erik
I had this experience twice with the audio note amp: I used the best film cap to replace the second failure, but my customer did not like sound outcome.
 
I had this experience twice with the audio note amp: I used the best film cap to replace the second failure, but my customer did not like sound outcome.

I agree...the AN caps sounds glorious and cannot competed by non oil film cap..
I've replaced that AN with Mundorf Silver in Oil and still Mundorf cannot compete with AN sound.
The good news is I just got response from Martin AN UK. I get replacement for my cap with a pair new batch AN caps. I have to send back the faulty cap to them.
They explain that the AN cap I got from PCX was the first batch of their production which is some troublesome (they admit it in their AN website). I hope the new pair much better than the old pair.

I also bought a pair Jensen paper tube so I can compare the sound with the new AN caps..

cheers....
 
I agree...the AN caps sounds glorious and cannot competed by non oil film cap..
I've replaced that AN with Mundorf Silver in Oil and still Mundorf cannot compete with AN sound.
The good news is I just got response from Martin AN UK. I get replacement for my cap with a pair new batch AN caps. I have to send back the faulty cap to them.
They explain that the AN cap I got from PCX was the first batch of their production which is some troublesome (they admit it in their AN website). I hope the new pair much better than the old pair.

I also bought a pair Jensen paper tube so I can compare the sound with the new AN caps..

cheers....
thanks for the the information. I think I have some mailing to do. Thanks again.
 
This is what AN says.
BIG Capacitor News!

Well, the really big news is that we have moved all our copper foil signal capacitors away from using a paper dielectric to using the same mylar that we use in the silver foil, but we retain the oil, so all our copper foil signal capacitors are now oil filled using mylar instead of paper, one slight abnormality, we have two print machines for these caps and for one of them we have not got the new print blocks that say “copper foil/mylar in oil” yet, so they still say paper in oil, however the print is now white instead of black, so we can see the difference, I know this is confusing, but it is temporary, I can assure you!

Why did we move to oil filled mylar from oil impregnated paper you may well ask?

When truth be told we have been experiencing increasing problems with the failure rate of our paper in oil capacitors over the past 3 to 4 years and despite a major research program into the causes of this increasing break down rate we have really come up with a blank, which makes me suspect that the cause has to do with subtle changes in the chemistry of the paper, the oil or some other key part of the caps, possibly due to new environmental requirements imposed on the production of the paper, who knows? Anyway, when it became obvious that we were unable to fully establish and rectify the cause, my engineers and I decided to give mylar a go again as the first experiments we did with oil imperegnated mylar was not sonically satisfactory, so this time we changed the construction to oil filled, the materials sealing the capacitor and the way we connect the foil ends to the wires and voila! After some running in, the new mylar/oil filled capacitors actually sound better in most respects than the old paper signal caps they replace, only real drawback in my view is that they take nearly twice as long to run in and sound quite a bit worse than the old paper/oil type when they are new, so there you are, you don’t get something for nothing!

Due to the problems that have emerged with the paper in oil signal capacitors I have decided that we should replace any faulty copper bodied Audio Note copper foil paper in oil caps that any of you have*, all you need to do is send them back to me here at Montefiore Road in Hove and they will be replaced free of charge with one of the new mylar versions. One thing though, you need to mark each capacitor up with what is wrong with it, if you don’t mind.

* Please remember that this replacement offer only covers copper bodied Audio Note capacitors and DOES NOT cover the previous yellow / gold bodied versions.

As mentioned in both the Audio Transformer and Wire & Cables Sections, the cost of most raw materials has gone through the roof over the past 3 - 4 years, our bulk purchasing of foils, wire, HiB and nickel have only started seriously affecting our cost over 2007, in spite of this I have decided not to increase our prices yet, although if the cost of the raw materials do not stabilise or come down over the next few months, prices will have to rise.
 
MKV

Don't forget the good old and still new available MKV capacitors. Original produced by Siemens (Germany). Later Siemens sold the MKV to Matsuhita and now Epcos owns it.

MKV are double metalized paper with polypropyleen dielectic. They sound super (Allen Wright from Vacuum State used them).

I still have much 0,22µF/900V MKV in my basement.

Ohh, and Siemens used the more reliable and even better sounding mineral oil :)
 
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Don't forget the good old and still new available MKV capacitors. Original produced by Siemens (Germany). Later Siemens sold the MKV to Matsuhita and now Epcos owns it.

MKV are double metalized paper with polypropyleen dielectic. They sound super (Allen Wright from Vacuum State used them).

I still have much 0,22µF/900V MKV in my basement.

Ohh, and Siemens used the more reliable and even better sounding mineral oil :)
Thank you esltransformer for such valuable information.
 
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This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.