Author Topic: Dead Dueland CAST caps  (Read 3313 times)

Offline skc

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Dead Dueland CAST caps
« on: June 10, 2014, 10:00:12 AM »
I have recently moved to Melbourne, and despite the packaging and express instruction, it seems one of my monoblocs is not very healthy. Initially I suspected there was likely some sort of mechanical damage, but then on opening the amp up, I noticed that one of .47 630v Cast signal caps seems to be VERY oily.

I can't find any loose connections, and there is no other evidence of anything in the amp not being right. I have swamped the amp out and everything sounds fine; I have swapped the valves between amps and the same amp is still the issue.

Is this oily cap the likely culprit?


Offline hedalfa

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Re: Dead Dueland CAST caps
« Reply #1 on: June 10, 2014, 12:27:02 PM »
When you say oily, there is oil on the outside of the cap??

Offline Pixelplay

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Re: Dead Dueland CAST caps
« Reply #2 on: June 10, 2014, 02:55:38 PM »
I have a CAST CU .1 that is leaking and have contacted Duelund. The answer from them was to return it to parts connexion for a replacement. So far it has not failed though.

Cheers
Greg

Offline stevenvalve

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Re: Dead Dueland CAST caps
« Reply #3 on: June 10, 2014, 06:56:24 PM »
I have 4 / 0.47 cast Duelunds sitting on a table, and a few weeks ago I noticed one has oil around the leads, I resealed it, but if it was not seen and all the oil leaked out unseen inside the amp That could be a problem, Leaking a little oil will not stop it working. They will probably work with no oil, it is i think mainly a dielectric but most likely will not sound as good.
« Last Edit: June 10, 2014, 07:00:46 PM by stevenvalve »

Offline skc

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Re: Dead Dueland CAST caps
« Reply #4 on: June 10, 2014, 08:59:46 PM »
When you say oily, there is oil on the outside of the cap??

Yeah, there is oil all over the outside of the cap, and even a little oil on the bottom plate of the amp itself. It has definately stopped working through.

Thanks guys.

Offline hedalfa

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Re: Dead Dueland CAST caps
« Reply #5 on: June 10, 2014, 10:29:02 PM »
Houston we have a problem?? I hope this isn't a sign of manufacturing fault, its sounding like it may be.

Offline guru

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Re: Dead Dueland CAST caps
« Reply #6 on: June 10, 2014, 11:53:07 PM »
Oil leakage from caps can be caused by poor location choices and orientation close to heat sources in confined enclosures. There will be expansion issues of the outer enclosure if subjected to heat as well as value drift, particularly over time.

Offline skc

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Re: Dead Dueland CAST caps
« Reply #7 on: June 11, 2014, 05:49:12 AM »
I've spoken to Dueland and although only one cap is an issue, they have asked that I return them all for replacement, just in case there cold be any issue with the others. Although they are not charging me for the parts there is still a waiting period until the new ones are produced as it summer holidays.

Offline Pixelplay

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Re: Dead Dueland CAST caps
« Reply #8 on: June 11, 2014, 07:53:09 AM »
My one was leaking even before I soldered it in, I thought that it just may be residue left over from manufacture.

Offline zenelectro

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Re: Dead Dueland CAST caps
« Reply #9 on: June 11, 2014, 11:34:52 AM »
The oil is part of the dielectric that has to withstand the 630V rating.

Once it starts to leak, sound aside, I would not be relying on that 630V rating anymore!  ;) ;)

Z

Offline Jehuty

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Re: Dead Dueland CAST caps
« Reply #10 on: June 12, 2014, 07:45:14 AM »
The oil is part of the dielectric that has to withstand the 630V rating.

Once it starts to leak, sound aside, I would not be relying on that 630V rating anymore!  ;) ;)

Z

Zen, when are we going to see your own manufactured oil filled caps/transformers? I'm sure members here are happy to try them  :)
Not all that matters can be measured, not all that can be measured matters.

Offline hedalfa

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Re: Dead Dueland CAST caps
« Reply #11 on: June 12, 2014, 08:23:36 AM »
Yeah, there is oil all over the outside of the cap, and even a little oil on the bottom plate of the amp itself. It has definately stopped working through.

Thanks guys.

Forgive me for stating the obvious yet they should be made to contain the oil reliably, any kind of leaking isnt  acceptable. I have seen caps in use that must be 50 years old and no oil residue.

Offline Pixelplay

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Re: Dead Dueland CAST caps
« Reply #12 on: June 12, 2014, 09:19:12 AM »
no a good sign

Offline stevenvalve

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Re: Dead Dueland CAST caps
« Reply #13 on: June 12, 2014, 07:49:24 PM »
I have had about 4 fail, Some being the VSF model, the VSF are now beefed up, This leaking cast is a problem, because it was not fitted into an amp, so there is no heat to blame.

Offline omodo

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Re: Dead Dueland CAST caps
« Reply #14 on: June 13, 2014, 09:00:58 PM »
...I have seen caps in use that must be 50 years old and no oil residue.

plenty of old caps would have leaked/have leaked, just they are in land fill and the good ones are in amps  ;D

Offline hedalfa

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Re: Dead Dueland CAST caps
« Reply #15 on: June 13, 2014, 11:06:07 PM »
plenty of old caps would have leaked/have leaked, just they are in land fill and the good ones are in amps  ;D

Yes but the good ones as you say last..............