Marantz 2285 Restore

Discussion in 'Marantz Audio' started by rhodus, Mar 22, 2018.

  1. Steven Tate

    Steven Tate AK Subscriber Subscriber

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    N. Richland Hills, TX
    :rflmao: That made me laugh out loud. IMO, if it sounds better to you, that's all that matters. Sounds like it worked out for you. Enjoy that 2285. It's a special unit. :thumbsup:
     
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  2. wurlyman

    wurlyman Active Member

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    I'm not going to get into the Noah Shumacher bashing. I bought the mods after reading all I could find about them. Here's the posted results comparing the before and after installation.
    [​IMG]

    My ears will be the final test and as far as keeping the unit stock, it's too late and I really don't care. I got the same flack when I converted my Klipsch KHorns to Greg Roberts Volti modifications. The only thing Klipsch in them now is the wood cabinet and I've never regretted it for a minute. It's time to start respecting each other here and realizing that our purpose is not to police but to support.
     
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  3. rhodus

    rhodus Active Member

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    234
    Location:
    Denham Springs, Louisiana
    KHorns...Ooooohhhh..If I ever build a new house, they will be included in the mortgage.
     
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  4. Osibisa

    Osibisa AK Subscriber Subscriber

    Messages:
    285
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    New Jersey
    So back to your restore ... have you changed out the main caps yet, if so did you bump up to 15,000 or 18,000?
    I have one that I did not do anything to other than rebuild the PS because the original owner installed or had installed an incorrect voltage relay. Did a number on some of the traces too.
     
  5. rhodus

    rhodus Active Member

    Messages:
    234
    Location:
    Denham Springs, Louisiana
    That's funny, I am looking at the package from Mouser with two 18000uf 75v caps in it! Mailman just dropped it off. Yea, the reason my friend decided to do this is the headphone jack had been damaged. That was an easy fix and once I powered it up I realized it was in pretty good shape for 40 years old. The main caps don't show any signs of leaking and all the voltages are in spec. After thinking about it he decided to move forward. It is very well built and fairly easy to work on so here we go!
     
  6. Osibisa

    Osibisa AK Subscriber Subscriber

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    285
    Location:
    New Jersey
    Agreed, it is a fine sounding amp and mine still sound great too. I think that replacing the mains with 15,000uf instead of going higher and then leave it alone for the time being will be my plan.
    Good luck with the restore.
     
    Last edited: Mar 24, 2018
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  7. rhodus

    rhodus Active Member

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    Well I got the 18000uf 75v filter caps installed. These are the tallest caps you can use here and still put the metal top cover back on. IMG_20180323_191313659.gif IMG_20180324_155804510.gif IMG_20180324_160827720.gif IMG_20180324_170226703.gif IMG_20180324_170804396.gif
     
  8. rhodus

    rhodus Active Member

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    234
    Location:
    Denham Springs, Louisiana
    No audible difference after replacing the main caps. Obviously the originals were still good.
     
  9. rhodus

    rhodus Active Member

    Messages:
    234
    Location:
    Denham Springs, Louisiana
    Just read a post by leestereo that indicates my grounding of the main caps is not good enough. I will go back and tweak it following leestereo's recommendations. Will post photos.
     
  10. rBuckner

    rBuckner Luv 2 Restore Subscriber

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    YES. Amen to this!! Well said.
     
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  11. rBuckner

    rBuckner Luv 2 Restore Subscriber

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    I do like the fat house sized wire you used for sure!!
     

     

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  12. rhodus

    rhodus Active Member

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    I think electrically it is good but I do agree with leestereo that the grounds should be center tapped at the chassis to be proper. That's the way Marantz designed it.
     
  13. rBuckner

    rBuckner Luv 2 Restore Subscriber

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    I confess to not having read the entire thread. Oops. It may be taken that I don't care that the person being pointed out for past, and maybe present and future actions was okay by me and was being defended by me. I only meant that we, as the AudioKarma community should be about supporting each other and not disrespecting each other's opinions. I snipped out and repeated what I was addressing with no consideration as to the previous posts. Keeping it all positive as much as possible is my goal and 99.9% of AK members. I'm sorry I didn't read the whole thread and realize what I may have been presenting. People have been screwed by several technical vendors and I'm never in favor of these actions!!
     
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  14. wurlyman

    wurlyman Active Member

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    246
    Location:
    Sacramento, CA
    I had the same intention.
     
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  15. rhodus

    rhodus Active Member

    Messages:
    234
    Location:
    Denham Springs, Louisiana
    IMG_20180330_125234767.gif IMG_20180330_133125624.gif Here is my new ground connection. It isn't pretty but the solder joints are solid. In the course of this work the ground screw threads in the chassis became stripped. What I have here is an output transistor mounting screw from my parts bin with a nut on the backside and lockwashers on both sides. The screw head is painted black but only the head. Again, no audible difference. It sounded great before and it still sounds great but I am happier with this connection.
     
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  16. rhodus

    rhodus Active Member

    Messages:
    234
    Location:
    Denham Springs, Louisiana
    I am having an issue with this unit. The protection relay engages immediately on power on, no delay. That is causing a nasty popping and crackling until the caps charge and the unit stabilizes. Once there it sounds great but I want to correct this. Any guidance would be appreciated.
     

     

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  17. wlhd1610

    wlhd1610 Penny and her new friend Sponsor Subscriber

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    Check your timing cap/resistors on the power supply board for the protection circuitry.

    Isolate the preamp from amp on back panel to see if your issue is amp or preamp dc.
    Also monitor the dc offset ahead of speaker relay .

    Bob
     
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