NOS Capacitors?

Discussion in 'General Audio Discussion' started by CT Jim, Sep 11, 2017.

  1. CT Jim

    CT Jim AK Subscriber Subscriber

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    I believe capacitors have a finite life, however, it seems like if used regularly they live way longer than expected.
    But, what about vintage or NOS caps? I mean manufactured in 60s, 70s, 80s, but never used? Can we be comfortable considering them new, especially if they measure out to the proper rating?

    If never used, they were dormant, so does their life start once powered in a circuit???
     
  2. Blue Shadow

    Blue Shadow I gotta get me a new title

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    The 'lytic caps have an electrolyte in them. This can dry out from any form of a leak to the environment. The material can migrate and form thicker or thinner layers of the material causing changes in the cap. And the electrolyte can do like a battery, lose its electrical performance somehow (ConradH knows) making it necessary to reform the cap which is what folks do when they fire up a long dormant device in 10V steps over time.

    With all that can be wrong with a vintage NOS Cap, electrolytic, I would not think that a simple measurement will give you all the information you need before putting it to use. Those that can test all aspects of the cap may give further info as to whether even a complete test will provide an answer as to whether the cap is ready for use.
     
  3. DaveVoorhis

    DaveVoorhis Super Member

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    Modern capacitors are typically better quality, better constructed, and therefore likely to be longer-lived than vintage or NOS caps. Some old caps are excellent -- for example, I have Sprague caps in vintage test equipment that are still going strong -- but other caps beside them (even made by Sprague) have had to be replaced. I prefer replacing them with new units.
     
  4. ev13wt

    ev13wt Super Member

    If they are correctly in storage. with special gasses and what not... maybe...

    But basically, its a dumb idea. Go new.

    Unless you are restoring to actual original specs and NEED them to be NOS. I can totally understand that.
     
  5. CT Jim

    CT Jim AK Subscriber Subscriber

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    The question started with my buying some 33uf offered as a 4 pak plus a couple bucks mailing. I needed 2 for an Advent speaker crossover, and I would have 2 for spares. I missed the NOS part and didn't realize these were new but old stock. I'm not out any big money, but don't want to use something that may fail after selling. I suppose even new could fail but I usually buy from Mouser and PE, so I guess the question is more rhetorical for informational purposes!
     
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  6. Freddymac2

    Freddymac2 Super Member

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    Either way you will be fine due to the fact that crossover caps are not stressed, by heat or current. I'ii state as I have before that Mylar or PP caps sound better to me, and will last for a very long time. Some say that their speaker was voiced with those caps and should not be changed, in most cases this is just BS.
     
  7. toxcrusadr

    toxcrusadr AK Subscriber Subscriber

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    What type of caps are those 33's? Nonpolar electrolytics or films? How old?

    I'm going to guess these are NPE's because films would be huge at 33 uf. And I would not use an NPE more than a few years old. In fact a 33 uf NPE from PE would probably cost 50 cents...OK correction, 98 cents.

    https://www.parts-express.com/cat/n...eca:matches(.,"P_Searchable","1")]&PortalID=1

    Films in that size are $9 and up at PE so if these are actually films and not decades old, I would be all over them.
     
  8. CT Jim

    CT Jim AK Subscriber Subscriber

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    These NOS caps are by ElCap. non-polar. I did look at Mouser and PE, and don't recall any 98 cent caps, but that doesn't matter at the moment.
    I'm not spending $6.99 shipping for something that goes in a 10cent envelope with some cardboard around it, and postage of a $1.
    I more than happy to add them to a future order, but I recently received a Mouser order, and do not plan on ordering for awhile!

    I hate to use combo sets of special caps I have like solen or auricap, so I'll just wait it out until the next order.
    What I ordered was presented correctly, I just missed the NOS which would have reminded me of the age issue!
     
  9. restorer-john

    restorer-john Super Member

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    I've got some vintage 50s/60s/70s caps that I wouldn't hesitate to use. Not electros however. It makes no sense to use a 40 year old NOS electro unless you enjoy russian roulette-like games.
     
  10. Blue Shadow

    Blue Shadow I gotta get me a new title

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    50V--48¢--https://www.digikey.com/product-detail/en/nichicon/UVP1H330MPD1TD/493-12703-1-ND/4328320

    100V--87¢--https://www.digikey.com/product-detail/en/nichicon/UVP2A330MHD/493-16145-ND/2539608

    Shipping--FREE--* When a check or money order accompanies your order, Digi-Key pays all shipping and insurance (our choice for method of shipping) to all addresses in the U.S. and Canada. From Digikey's Terms and Conditions page.

    Got a Stamp? Envelop? Remember snail mail? Still got checks?

    Digikey does like for you to pay state sales tax whether they have a presence in your state or not. I don't know what they do with that money but that few cents per dollar isn't much to add to avoid the $4.99 slow boat shipping from Mouser.
     
  11. toxcrusadr

    toxcrusadr AK Subscriber Subscriber

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    I did that recently with Digi-key. It's buried in the shipping terms and not a selection on the order page. I got a $3 part sent by mail in an envelope and it got here in two days with zero shipping cost. As I recall, I did not have to actually mail them a check either. The details are in another thread, I'll look it up if anyone is interested.

    PE does have those 98 cent nonpolar electrolytics - gotta pick the NPE category out of the 3 selections on the capacitor page.
     
  12. Blue Shadow

    Blue Shadow I gotta get me a new title

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    I'm in for details. Sure beats worrying about whether the term dumpster-diver is derogatory being discussed on that other thread where I won't post.
     
  13. DaveVoorhis

    DaveVoorhis Super Member

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    Triggered!!!1!1!! :mad:





    Kidding!
     
  14. toxcrusadr

    toxcrusadr AK Subscriber Subscriber

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    :p

    Here ya go.

    http://audiokarma.org/forums/index....ork-for-a-motor-run-cap.778661/#post-10691978

    In addition to the 'free shipping if paid by check', there is another option that I ended up using: a $3.99 shipping option for up to 14 oz that is waaaay at the bottom of the shipping choices list. This allowed me to pay with a CC and save a lot of time mailing a check, and they actually charged only $2.85 to ship my one part.
     

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