Parts lists for recapping popular amps/receivers?

Discussion in 'DIY' started by birchoak, Jun 13, 2018.

  1. birchoak

    birchoak Hi-Fi Nut Subscriber

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    Forgive any ignorance on my part, but does the AK database have recap parts lists for popular amps/receivers?

    For example, instead of poring over blurry schematics or trying to see the writing on teeny little caps buried beneath another board, it would be great to access a typewritten list of capacitors needed. I thought about this as I dug into the guts of a Sansui 800 this morning. Maybe the list could look something like this:

    Topside of Chassis
    Note: Save old caps in case new ones too small for retaining clamps (hollow out, hot glue new ones inside old shells)
    (3) 2000uF 35V filter capacitors, radial leads
    (1) 2000uF 60V filter capacitor, radial

    Underside of Chassis
    (2) 1000uF 16V capacitors, axial leads
    (2) 470uF 25V capacitors, axial
    (1) 330uF 35V "
    (1) 330uF 25V "

    R & L output boards
    Note: You may have to desolder ground straps to get enough slack to pull boards free for soldering; take photos first and remember to solder grounds back on or you will let the magic smoke out.

    (2) 1uF 50V

    And that's all I have so far--persons posting wouldn't be held liable for mistakes as these lists would be "used at your own risk" and mostly a way to confirm how many of what--selection of actual caps and their values would be up to the person actually doing the work. Thoughts? Do we already have these recap lists? If we don't, I would be happy to start posting my parts lists in a fashion similar to above.
     

     

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  2. Blue Shadow

    Blue Shadow I gotta get me a new title

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    There are many cap lists in posts all over ak. Maybe what you want is out there and a search would reveal it. Maybe not and you would need to forge ahead. Whatever Markthefixer has set the standard for a list using the info in the service manual to generate the list. The data included board number cap number cap size cap type replacement cap mouser number and maybe a bit more. Look one up and see what you think. MTF is mostly in the pioneer forum
     
  3. guest122

    guest122 Active Member

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    Someone had to dig through schematics to make the lists.
     
  4. gadget73

    gadget73 junk junkie Subscriber

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    They're around, just have to search by model number. Some are in posts, some are attached as files. I know I've uploaded a couple that were not already here.
     
  5. Blue Shadow

    Blue Shadow I gotta get me a new title

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    Or they could have just plowed through the unit in question and generated a list. But there are many in threads here on AK. Good place to start but always compare to what is actually in your unit. If your unit works replace like with like. If it doesn't maybe the schematic will be a better choice for the cap replacement.
     
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  6. zebulon1

    zebulon1 Getting behind on work. I need help? Subscriber

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    It takes some work to make a cap/transistor list. Plus it should be vetted for accuracy.
    I really admire the members who post one.
     
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  7. birchoak

    birchoak Hi-Fi Nut Subscriber

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    That sounds amazing; I will look.
     
  8. birchoak

    birchoak Hi-Fi Nut Subscriber

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    I tend to go by what's in the actual unit, including polarity orientation. I figure it left the factory working. Unless there's a service bulletin.
     
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  9. spark1

    spark1 Well-Known Member

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    If you're going to the trouble of recapping, you might think about also replacing any transistors and diodes known to become problematic, and address any known model-specific issues. And also trim pots.

    You'll get a lot better return on your time investment vs just replacing caps.
     
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  10. grey

    grey AK Subscriber Subscriber

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    Last edited: Jun 13, 2018
  11. spark1

    spark1 Well-Known Member

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    I guess it would be nice if there were detailed parts lists and step by step instructions written so that anyone, with any knowledge/skill level, could do the work involved in restoration/rebuilding old gear. Never seen such a thing, though. I have seen some excellent write-ups, but they all still assume some amount of prior knowledge and expertise. Additionally, good technical writing skills are a scarce commodity...it doesn't always follow that those who know how to do something can do a good job of documenting that information.

    In my case, I've enjoyed all the work required to get to my current (and quite low) level of competence....it's a process, and a journey, and I've found that there just aren't really any shortcuts to learning how to do good repair and restoration work. As with all subjects, there are layers of understanding. If you want to move beyond the first layer, it's going to take some work.

    I guess if your unit has no issues, then there's no need for troubleshooting, and you can just replace parts. Generally, this doesn't require a lot of knowledge. But I've found that with most of the gear that can benefit from a rebuild, the situation is often not that straightforward. There are often problems that must be diagnosed and resolved before rebuilding...and of course, even with decent skills, mistakes get made....again, requiring diagnosis and repair skills beyond simple parts swapping.
     

     

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  12. gadget73

    gadget73 junk junkie Subscriber

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    Some of this gets into a case where if you need step by step instructions, perhaps you ought not be tackling such a job. A full re-cap is not exactly a beginner exercise. I know that sounds a bit condescending but its very possible to get into big trouble by doing bulk parts replacements without some experience.
     
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  13. Bob

    Bob AK Subscriber Subscriber

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    replacing parts is not what it's all about. the idea is that you list the parts on: 1) the board,
    2) parts list, 3) schematics (including all the service bulletins, notes, etc).

    all three must be identical then when all the parts have been verified correct and complete
    you can do the economic lots, the upgrades for resistors (CC, CF, MF, etc), upgrades
    for caps (material, voltage, value).

    the learning process is the journey, what you learn helps you understand, helps you
    determine what is good/bad, what makes it more reliable, what makes for good sound
    quality.

    getting a random BOM (if they're not from AK's giants) then you may find missing items
    and/or explanations. and completely skipped the learning process. and without the
    eventual understanding and epiphany.
     
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  14. OMGCat!

    OMGCat! AK Subscriber Subscriber

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    Add in that a lot of people are doing "recaps" to try and correct some other unrelated issue and it's a recipe for disaster. I like to make repair threads occasionally but I figure most people reading along already have some experience and test gear so they won't be caught out on things that I don't mention.

    As far as using someone elses BOM, I would be nervous. I hate having to make a second parts order because one or two small parts are off so I'd much rather do the looking myself. I usually make a list with what's in the manual then compare it to what I see in the machine. After that I make my cart, compare again and then place the order.
    Then when inevitably I miss something anyway I start sweating and hope I have it in stock.
     
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  15. gadget73

    gadget73 junk junkie Subscriber

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    agreed, always confirm the BOM with the unit in front of you. It can be a starting point though.

    Also definitely agree about diagnosing any problems before throwing parts at it. The last few times I had problems that I assumed would be caps it turned out to be leaky transistors.
     
  16. zebulon1

    zebulon1 Getting behind on work. I need help? Subscriber

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    Its a serious labor of audio love, mostly for yourself but others benefit. A wonderful byproduct.
    Go through the component itemized list.
    Inventory the set taking notes and accurate comparisons between the item list and whats actually there.
    Probably have the set set pulled apart and components partially removed for verification.
    Mouser, DigiKey lists compiled, so saving shipping costs.
    Reading up on all the the AK and other threads concerning the unit.
    Wow!
    Fun!
    Then getting something out of it, no one can take away.
     
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