Filter caps, selection and technique for reconnecting

Discussion in 'Pioneer Audio' started by Gobstopper, Apr 13, 2017.

  1. Gobstopper

    Gobstopper Active Member

    Messages:
    183
    Location:
    Oakland, CA
    Hi Everyone,
    I'm working on an SA-7100 and was contemplating replacing the filter caps. I know the big sized ones are getting harder and harder to find all the time. I started looking through the forums and ran across this post:
    http://www.audiokarma.org/forums/index.php?threads/my-sa-7100-drops-in-and-out-of-protection.497819/

    where the OP followed patfont's thread: http://www.audiokarma.org/forums/showthread.php?t=503150
    in using Panasonic THA caps. (Patfont used them since they laying around)

    In general I know that high ripple current rating and low ESR are the things to go for, but looking at Nichicon caps at least, I can't get a feel for which series (e.g LGU, LGY, KG, etc) have the better specs. LGU's seem affordable and will fit.

    The same Panasonic THA is still available, but is a bit more pricey than the Nichicons.
    I wasn't sure if there were better options in that class.

    Finally, I was wondering if someone had links with pictures on how to best reconnect the wiring the snap-in type terminals. On the SA-7100 the connections to the filter caps are wire-wrap. In the first thread I mentioned I think the OP did a regular soldering connection. I've seen a few posts were Mark The Fixer mentions using "Experimenter's board", and Patfont in his post did something cool with what I believe are crimp connectors. I've also seen a few posts where people "re-stuff" the cans, although that wouldn't help too much since I can't duplicate the wire wraps, and I don't think the old caps are that huge. Any visual guides out there that someone could point me to?

    Thanks again!
     
  2. ivandezande

    ivandezande Super Member

    Messages:
    1,016
    Location:
    minnesota
    As long as the caps are name brand (Panasonic and Nichicon are great) and have good numbers the series is probably personal preference.
     
  3. Blue Shadow

    Blue Shadow I gotta get me a new title

    Messages:
    17,487
    Location:
    SE PA
    And this is why you can select your caps by color!! As long as the first parts of the statement is followed.
     
  4. markthefixer

    markthefixer On Hiatus, dealing with Dad's estate full time Subscriber

    Messages:
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    Location:
    Bensenville,Illinois
    physical size is the most important consideration. then to increase size, going up in voltage is good.

    caps were spec'd back then as -20% +80% so going up in capacitance isn't a problem - although huge jumps might want power rectifier diode replacements or even upgrades due to increases in inrush current upon power up.
    Be aware that if a unit uses the dual diode metal bridge assembly style rectifiers, upgrading is unnecessary.
    THEY were used in everything up to and including the SX-1980.
     
  5. KingBubba

    KingBubba "Too Much Stuff" Subscriber

    Messages:
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    Location:
    Brooksville, Fl.
    When using the snap-ins, like the Panasonics, the contact is a more like a pin than a lug. I had seen a post many years ago that suggested adding a lug with a ring to the cap contact pin. This gives you an easier surface to solder your wires to. I usually put the ring lug on to the pin, use the crimper to tighten the lug on and then follow up with solder to finish it up. I wondered if the act of soldering the wire later would cause the lug solder to melt. This was never a problem. Panasonic is apparently dropping its snap in line of caps, but there still seems to be a lot of them out there.
     
  6. sKiZo

    sKiZo Hates received: 8641 Subscriber

    I just snip the original terminals from the old caps and solder those to the pins ... no wrapping involved, and no issues with snipped leads being to short to reach ...

    [​IMG]
     
    dlucy likes this.
  7. Gobstopper

    Gobstopper Active Member

    Messages:
    183
    Location:
    Oakland, CA
    Thanks Everyone for the replies. I guess I'll go for the LGU series. sKiZo, if I am understanding correctly, you clip the original terminals from the old cap(as close to base as possible I suppose) and then solder the old terminal+wirewraps onto the new terminals? Brilliant!
     
  8. sKiZo

    sKiZo Hates received: 8641 Subscriber

    Yup ... here's the original donor caps ...

    [​IMG]
     
    rcs16 likes this.
  9. rcs16

    rcs16 Super Member

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    2,818
    Location:
    Baldwin, Ontario, Canada
    The SX-1050/1080 are exceptions.
     
  10. hopjohn

    hopjohn Kenwood Krazy Subscriber

    Messages:
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    Location:
    Dallas, TX
    Are you doing anything to ensure a mechanical connection here?

    In spite of the fact it'll probably never be an issue, IMHO it's probably not the most fundamentally sound soldering technique to encourage. Any loss in length by trimming and stripping the wires can be made up for by using ring terminals over the ends of the snap in leads and at the same time provide a solid mechanical mounting solution.

    Edit: Here's a photo description of what I'm suggesting.
     
    Last edited: Apr 16, 2017
    Hipocrates likes this.
  11. sKiZo

    sKiZo Hates received: 8641 Subscriber

    I'd love to hear how there's any difference between what I do and a normal connection between the pins and copper traces on a circuit board ...

    :lurk:
     
  12. Hipocrates

    Hipocrates AK Subscriber Subscriber

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    Nope, it doesn't.
     
  13. hopjohn

    hopjohn Kenwood Krazy Subscriber

    Messages:
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    Location:
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    @sKiZo You seem offended and if so I sincerely apologize. I'll just say that a good mechanical connection is textbook soldering technique and I use it whenever the opportunity presents itself.
     
  14. Awesomeaudio

    Awesomeaudio AK Subscriber Subscriber

    Messages:
    827
    Location:
    Sydney, Australia
    I'm glad you found mine and Pat's threads useful.
    That was a while back now I think of it.
    I still have my SA-7100 and still sounds great.
    A little scratchy in the controls but no big deal. Some electrical cleaner/ cleaner lube will solve this.
    As Mark said, the 1st thing is to make sure the new caps actually fit your clamps/unit, then consider going higher in spec to give some head room for those voltage spikes.
    I chose the Panasonic becuase I was new to DIY and trusted Pat's recommendation.
    Always try and stick with name brands for quality control.
     

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