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DIY: good intro to capacitor type

DonH56

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#3
Gould? Wima? YouTube? :)

Not a lot about some of the pros and cons for audio signal coupling applications... Ceramics are generally avoided, for example, due to their strong piezoelectric properties (capacitance varies with voltage).

I'm sure any of us with techie backgrounds has many stories of seeing the inside (and sometimes outside) of components and speakers littered with electrolytic capacitor detritus... The other types usually just melted or burned, but electrolytics like to spray their guts everywhere.
 

amirm

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#5
Gould? Wima? YouTube? :)
First one! Gould was actually a holding company and owned a bunch of companies including the $300M computer company by the same name in 1980s.
 

DonH56

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#6
First one! Gould was actually a holding company and owned a bunch of companies including the $300M computer company by the same name in 1980s.
Yah, of the names I saw only Gould was a contender (the other two were jokes as I'm sure you knew, though I've been meaning to ask Thomas if he has found any incriminating YouTube vids... :) )
 

amirm

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#7
Yah, of the names I saw only Gould was a contender (the other two were jokes as I'm sure you knew, though I've been meaning to ask Thomas if he has found any incriminating YouTube vids... :) )
As you know, youtube is owned by Google. Shortly after Google was formed I received a call from a recruiter asking if I want to work for these two guys who had built a neat search engine. I told him to get lost as Yahoo had this locked down and no one else had a chance! Teaches you to not listen to me on business matters. :) At least not the much younger version of me then....
 

DonH56

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#8
I had forgotten the Google connection but not something I pay attention to (and don't really "do" youtube). I have a couple of similar stories about lost opportunities, maybe over a beer or a Scotch sometime...
 

maty

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#9
Talking about caps i just read this:

avahifi = Frank Van Alstine

https://www.audiocircle.com/index.p...dv66itrv74&topic=164876.msg1752734#msg1752734

[ The capacitor issue dates back 10 years ago or so when a engineer from one Japanese capacitor maker left the company taking what he thought was their proprietary formula for the fluid in their electrolytic capacitors. He went to a different capacitor maker and they put the new secret formula into their production parts. The formula also spread to other vendors too. Unfortunately it was not the correct formula. It caused many capacitors using it to fail after 8-10 years of use. This caused an industry wide problem that affected many Japanese capacitor makers, manufacturers using these parts and many previously considered good reliable parts.

We unfortunately were the recipient of a batch of these tainted parts. They worked fine for many years, and we, along with other users of these parts, had no idea of the hidden issue until these parts started failing for us.

The failure mode is that when these electrolytic capacitors start leaking, the fluid leaking out corrodes and dissolves the nearby circuit traces, often ruining the circuit board completely. The issue can also be identified with a close inspection of the boards in circuit. The evidence is a trace of black goo along the lower edge of the board. We actually had to run a new batch of our obsolete Insight series preamp line boards just to be able to offer repairs for our clients. These parts were used on our basic line boards, our line - tone control boards, and our phono boards of that older vintage. They were not used on the power supply boards or in any other AVA products... ]
 

gene_stl

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#12
I have a Crown XLS 602 amp which has one PS capacitor which splurped all over its circuit board. I am pretty sure that is all that is wrong with it.
There are further spaces on the board which I am going to try and populate after examining them. This amp is contemporaneous with the capacitor plague.
 
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maty

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#13
I knew about the plague but do not know about the article in The Gaurdian and the one that took the formula.
 
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