Metallised film caps get their "self-healing" properties by the metallisation burning away from failure points. Maybe that's what folks are talking about, but hard to believe there would ever be enough to matter.
YOS,
Chris
YOS,
Chris
With my audio projects, there is absolutely no tolerance for no name sheep china parts. Its literally a free of china parts zone, like all those old tube gear of the golden tube age.
Nobody needed such parts yesteryears, and nobody needs them today.
For saving three cents, I'm not willing to compromise on quality.
Very oldschool, I guess.
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Russian parts are a different story, their military PIO caps are dirt cheap survivors of the cold war soviet union times. You can use them without regrets, just test them for their sound signature. Russians never build bad parts for their military. It was all prooven to survive the next world war. Nevertheless, russian parts free zone, too. Even russian tubes, I never used them for the one reason, that there are plenty of good tubes in the western hemisphere exist.
P.S. Erratum, used the Sovtek 300B once. Not a bad tube for the money, but different sounding than a real WE.
P.S. Erratum, used the Sovtek 300B once. Not a bad tube for the money, but different sounding than a real WE.
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Think like a businessperson. If it does not matter, then you are using too much metalization. Make it thinner until it won't last 29 days, then go a hair thicker so your 30-day warranty costs are not excessive.
These ARE for line apps, across a low-impedance power line and possible kilo-VA loads cutting in and out. In audio we rarely face such abuse, so the caps may last longer.
Of course if a penny-pincher goes too far, the cap may fail short "for no reason". In line-app this blows a fuse. In audio it may blow-up the next device in the chain.
X-caps can lose some capacitance over time in their intended application (across the AC line) by dielectric puncture and self-healing due to AC inout transients. This should not be an issue when used as a coupling cap that is isolated from the AC line.
This is not normal ... some time ago only caps used at high frequency and high current , let's say in TV horizontal sweep stage , would have failed so easily .
At 50Hz the stres is minimal ... chinese crap . The issue is who would use those in a tube amp when we know that all the electrolytic caps are fakes that don't last either 😛
At 50Hz the stres is minimal ... chinese crap . The issue is who would use those in a tube amp when we know that all the electrolytic caps are fakes that don't last either 😛
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We used to own Philips cathode ray tube TV sets throughout, in the beginning it was all tubed sets, later transistorized. Had dozens of E- and P series tubes on boards and the big bottles for high voltage. You could heated a small room in winter with those. Heavy as a rock.
Those lasted at least minimum ten years, daily abuse included, in summer for sure HOT inside. 10 years wasn't much for them, some lived much longer with a little service. High voltage electrolytic caps, all kind of other caps worked under the most severe conditions. And it was just consumer stuff, but not cheap though.
Thats what I call quality and if you look inside of them, not one china/asia parts was used. Quality exists when the price is long forgotten.
Those lasted at least minimum ten years, daily abuse included, in summer for sure HOT inside. 10 years wasn't much for them, some lived much longer with a little service. High voltage electrolytic caps, all kind of other caps worked under the most severe conditions. And it was just consumer stuff, but not cheap though.
Thats what I call quality and if you look inside of them, not one china/asia parts was used. Quality exists when the price is long forgotten.
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Some capacitors in an amp are in the signal path. So you listen to them, in the music you hear. They are not perfect, they are certainly not neutral and transparent. They have an influence on the signal. Along with the other components, the tubes, the schematic, the speakers, the room... everything has a smaller or a bigger influence on the final result.
Its like cooking: the quality of the ingredients is a factor in obtaining a tasty dish. We taste the tomatoes - some have flavor, others taste like plastic.
I think it's the same with capacitors and other components. Some give a better result than others.
Does it matter? It depends. A capacitor's "sound" might be swamped by another factor's influence - the noise, your speakers, your ears...
But in some cases (a good headphone amp, for example), it's quite obvious.
These are the exact caps I received; looks like I ordered 100 nF and not 220 nF.
I wanted something small enough to go in my travel kit, just in case I needed some high voltage coupling caps while away from home base. You can always put "good" caps in later, after something is finalized and working.
I wanted something small enough to go in my travel kit, just in case I needed some high voltage coupling caps while away from home base. You can always put "good" caps in later, after something is finalized and working.
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It's your money to waste...
Frankly I think it's ridiculous not to use Chinese parts.
Oh and for the record, many of those fancy caps you buy from Digi-key including Nichicon are made in China. TI makes their regulators in China. Apple makes it's stuff in China. There is nothing wrong with Chinese parts if you aren't buying fake/counterfeit crap from eBay. Otherwise it's just a case of racism IMHO.
Agree on both counts. Colleagues have dismantled faulty metallised film self-healing caps. The measured fault was much reduced capacitance. They found destruction of the metal adjacent to the puncture in the film where the over-voltage had punched through. There was extensive erosion from the repair process. And agree that this is unlikely to occur when the caps are used away from powerful voltage spikes - as in most audio signal applications.
Yeah, folks rag on Chinese manufacturing while talking on their i-phones. Manufacturers provide what customers are willing to buy. If we insist that everything be as cheap as possible, we'll get stuff made as cheaply as possible.
The high rate of counterfeiting keeps small purchasers like DIYers away though. For good reason.
YOS,
Chris
The high rate of counterfeiting keeps small purchasers like DIYers away though. For good reason.
YOS,
Chris
For a hobby, the money is already spend for a luxury waste of time.
If one has no extra cash to spend-> no hobby is possible.
And for the chinese quality: You'll never know what you get from china. Is it fake, low quality product or is it good quality? Asians can and do fake everything, from Rolex to Hitachi large can capacitors. Those are famous fakes, well known among audiophools. Big black can caps.
And what do you think, why wealthy chinese always try to buy famous brand goods overseas, never directly in china? When they are taking their europe tour, they buy local all the goods they need, like the famous WMF cooking pots or the Meisner porcelain direct in germany. This is because they know that, if being bought in china, chances are great to be ripped off with fake goods.
You'll never know what quality you receive for your money.
Of course, they can build good products if you give them good money like Apple and all other famous electronics. But if you'r on the penny pincher side, beware of the fakes and lowest quality they will sell to you. Your money is nearly wasted but for my extra spend money on quality goods, this will make me happy a whole lifetime. And after 40 years of trouble free service I'll change the tube set for the very first time. Thats the difference. It was never foolish to spend money for prooven quality goods. Because you know what you pay for.
In former times, everything in life has to be bought just one time. Because it was made to last. Then came the marketing department and told people to buy a new Chevy every year because the tail lights have changed from vertical to horizontal and thats the newest fashion. What, if your neighbor would spot you in a yesteryears car? For me, this is with audio abolute irrelevant. The gear I DIY can be given to my children and after a small service even to their children as fully functional museum pieces. That wouldn't happen with chinese audio parts, for sure.
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yes, self healing is the mechanism, but have you some data to show? like how many samples were tested and to what extent did the capacity changed? if we can not quantify, then we have nothing...but opinions....
Not an opinion - a reported data point
One self-healing cap. One self-healing cap measuring at less than spec. One self-healing cap dissected, displaying erosion and punch-through. One self-healing cap cap behaving as designers intended - self healing. One self-healing cap showing a consequence - lower than spec capacitance.
One self-healing cap. One self-healing cap measuring at less than spec. One self-healing cap dissected, displaying erosion and punch-through. One self-healing cap cap behaving as designers intended - self healing. One self-healing cap showing a consequence - lower than spec capacitance.