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RE: [dallasaudioclub] Electrolytic capacitor info for you DIY'ers

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  • Paul Stewart
    Good info! To: dallasaudioclub@yahoogroups.com From: jim@fmtunerinfo.com Date: Tue, 22 Jul 2008 12:13:47 +0000 Subject: [dallasaudioclub] Electrolytic
    Message 1 of 3 , Jul 22, 2008
    • 0 Attachment
      Good info!


      To: dallasaudioclub@yahoogroups.com
      From: jim@...
      Date: Tue, 22 Jul 2008 12:13:47 +0000
      Subject: [dallasaudioclub] Electrolytic capacitor info for you DIY'ers

      Hi guys,
      Below is a copy and paste post from my FM tuner group. OH LOOK! My
      favorite brand,Panasonic, was not part of the problem.
      8:-) jim...

      Re: Upgrade or Replace Caps

      Yes Tom,

      Right on target.

      That bad formula made their way into just about every Taiwanese,
      Chinese, and Korean electrolytic cap manufacturer.
      Very quickly, the cap manufacturers who chased after the cheap
      formula became identified, as the first products to fail were
      computer motherboards, requiring stable capacitors.
      Those computer motherboards using (good for the Japanese - they still
      have a conscience about quality) Panasonic, United ChemiCon or
      Nichicon Capacitors were remarkably trouble-free. It became perfectly
      obvious which cap manufacturers were NOT using the bad formula,

      http://www.pcstats. com/articleview. cfm?articleID= 195

      http://www.siliconc hip.com.au/ cms/A_30328/ article.html

      Even today, after a couple of years, since the bad formula problem
      was supposed to have passed, we still see Luxon, Rubycon, and many
      other types of caps, swollen, and leaking electrolyte.

      For that reason alone, we use only Panasonic, Nichicon or United
      ChemiCon electrolytics.
      BTW, Vishay's electrolytic caps are just too expensive to find their
      way into the computer motherboard market, but rest assured that their
      caps (Roderstein, Sprague, BCComponents, Philips) are probably the
      most reliable and longest life caps available today.

      And we never touch NOS (New Old Stock) capacitors.

      I personally don't like Tantalums, because when they fail, they
      SHORT, with disastrous results for hard-to-find tubes, and
      semiconductors.
      All other capacitors, when they fail, (barring any extraneous
      circumstances) they will fail OPEN!

      But Tantalums are DIRT CHEAP, so you will find them in many
      applications today, where the emphasis is on profits, and not quality.

      We had a well-known manufacturer who was very keen for us to start
      using their Tantalums.
      We finally gave in and said, OK, send us 100 samples for evaluation.
      After testing, it turned out that although all 100 were within the
      specified 5% capacitance tolerance, only 6 of the 100 were within ESR
      limits. 94 failed the tolerance test.

      And that was supposed to be from a cherry-picked batch, in order to
      convince us to buy production quantities! We gently informed the
      manufacturer that we wouldn't be buying their tantalums.

      Anyway, you can draw your own conclusions as to why today's
      electronic products have such a short lifetime.

      I prefer Wima MKS2 MPE capacitors, instead of Tantalums - in the
      order of x100's more stable, and compact footprints with up to 15uF
      currently available - in fact, they are probably the most compact
      Metallized Polyester caps in the world today. They (MPR and MPE) are
      also non-polar, so they substitute perfectly for any polarized cap.

      And I'll add to Tom's advice about the best place to start being the
      power supply - absolutely! The second place to concentrate is the
      audio path - that's where you'll HEAR the difference.

      Menahem Yachad
      Israel





      With Windows Live for mobile, your contacts travel with you. Connect on the go.
    • dtproff
      I will add a bit more to the capacitor topic below. I am a power supply engineer and swollen capacitors are aren t always the fault of the manufacturer. The
      Message 2 of 3 , Oct 21, 2008
      • 0 Attachment
        I will add a bit more to the capacitor topic below.

        I am a power supply engineer and swollen capacitors are aren't always
        the fault of the manufacturer. The biggest problem I have found has
        been the misuse of an electrolytic by the design engineer. Ususally
        it is the result of the ripple current in the capacitor being too
        high. This causes the internal temperature to rise inside the cap.

        Check the spec on the capacitor then use a current probe to verify
        the ripple current into the cap. Pay attention to the frequency that
        the capacitor is seeing. If it is to large then add a film cap across
        it and then check the leg on the cap again. The film cap will have a
        lower ESR and shunt some of the current off the Aluminum
        Electrolytic. Be sure and test the leg of each capacitor and don't
        exceed the manufacturers published spec.

        Tony

        --- In dallasaudioclub@yahoogroups.com, Paul Stewart
        <musicman32150@...> wrote:
        >
        >
        > Good info!
        >
        > To: dallasaudioclub@yahoogroups.com
        > From: jim@...
        > Date: Tue, 22 Jul 2008 12:13:47 +0000
        > Subject: [dallasaudioclub] Electrolytic capacitor info for you
        DIY'ers
        >
        >
        >
        >
        >
        >
        >
        >
        >
        >
        >
        >
        >
        >
        >
        >
        >
        >
        >
        >
        > Hi guys,
        >
        > Below is a copy and paste post from my FM tuner group. OH LOOK!
        My
        >
        > favorite brand,Panasonic,was not part of the problem.
        >
        > 8:-) jim...
        >
        >
        >
        > Re: Upgrade or Replace Caps
        >
        >
        >
        > Yes Tom,
        >
        >
        >
        > Right on target.
        >
        >
        >
        > That bad formula made their way into just about every Taiwanese,
        >
        > Chinese, and Korean electrolytic cap manufacturer.
        >
        > Very quickly, the cap manufacturers who chased after the cheap
        >
        > formula became identified, as the first products to fail were
        >
        > computer motherboards, requiring stable capacitors.
        >
        > Those computer motherboards using (good for the Japanese - they
        still
        >
        > have a conscience about quality) Panasonic, United ChemiCon or
        >
        > Nichicon Capacitors were remarkably trouble-free. It became
        perfectly
        >
        > obvious which cap manufacturers were NOT using the bad formula,
        >
        >
        >
        > http://www.pcstats.com/articleview.cfm?articleID=195
        >
        >
        >
        > http://www.siliconchip.com.au/cms/A_30328/article.html
        >
        >
        >
        > Even today, after a couple of years, since the bad formula problem
        >
        > was supposed to have passed, we still see Luxon, Rubycon, and many
        >
        > other types of caps, swollen, and leaking electrolyte.
        >
        >
        >
        > For that reason alone, we use only Panasonic, Nichicon or United
        >
        > ChemiCon electrolytics.
        >
        > BTW, Vishay's electrolytic caps are just too expensive to find
        their
        >
        > way into the computer motherboard market, but rest assured that
        their
        >
        > caps (Roderstein, Sprague, BCComponents, Philips) are probably the
        >
        > most reliable and longest life caps available today.
        >
        >
        >
        > And we never touch NOS (New Old Stock) capacitors.
        >
        >
        >
        > I personally don't like Tantalums, because when they fail, they
        >
        > SHORT, with disastrous results for hard-to-find tubes, and
        >
        > semiconductors.
        >
        > All other capacitors, when they fail, (barring any extraneous
        >
        > circumstances) they will fail OPEN!
        >
        >
        >
        > But Tantalums are DIRT CHEAP, so you will find them in many
        >
        > applications today, where the emphasis is on profits, and not
        quality.
        >
        >
        >
        > We had a well-known manufacturer who was very keen for us to start
        >
        > using their Tantalums.
        >
        > We finally gave in and said, OK, send us 100 samples for
        evaluation.
        >
        > After testing, it turned out that although all 100 were within the
        >
        > specified 5% capacitance tolerance, only 6 of the 100 were within
        ESR
        >
        > limits. 94 failed the tolerance test.
        >
        >
        >
        > And that was supposed to be from a cherry-picked batch, in order to
        >
        > convince us to buy production quantities! We gently informed the
        >
        > manufacturer that we wouldn't be buying their tantalums.
        >
        >
        >
        > Anyway, you can draw your own conclusions as to why today's
        >
        > electronic products have such a short lifetime.
        >
        >
        >
        > I prefer Wima MKS2 MPE capacitors, instead of Tantalums - in the
        >
        > order of x100's more stable, and compact footprints with up to 15uF
        >
        > currently available - in fact, they are probably the most compact
        >
        > Metallized Polyester caps in the world today. They (MPR and MPE)
        are
        >
        > also non-polar, so they substitute perfectly for any polarized cap.
        >
        >
        >
        > And I'll add to Tom's advice about the best place to start being
        the
        >
        > power supply - absolutely! The second place to concentrate is the
        >
        > audio path - that's where you'll HEAR the difference.
        >
        >
        >
        > Menahem Yachad
        >
        > Israel
        >
        >
        >
        >
        >
        >
        >
        >
        >
        >
        >
        >
        >
        >
        >
        >
        >
        >
        >
        >
        >
        >
        >
        >
        >
        >
        > _________________________________________________________________
        > With Windows Live for mobile, your contacts travel with you.
        > http://www.windowslive.com/mobile/overview.html?
        ocid=TXT_TAGLM_WL_mobile_072008
        >
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