Marantz 250M relay replacement help.

Discussion in 'Marantz Audio' started by gogofast, Mar 21, 2018.

  1. gogofast

    gogofast AK Subscriber Subscriber

    Messages:
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    Location:
    Seattle
    I'm in the process of recapping 250M. Was able to troubleshoot one channel out and loud hum. Now, all it needs is a recap and possibly a new relay.

    I've read every thread in AK and other forums regarding 250/250M relay mod using the MY2. None of the links and videos are still alive.

    Anyone with detailed information regarding this relay replacement? Whether modding the relay itself or the circuit board?

    Thanks in advance.
     

     

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  2. wlhd1610

    wlhd1610 Penny and her new friend Subscriber

    Messages:
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    Location:
    upstate new york
    I have been carefully modifying the Omron MY2-02 relays successfully for years now.
    I first saw it on Chrismarantz's Faultlineaudio site which is no longer active.
    I just did one yesterday for a client's 240 amp.
    It's delicate work but beats some of the High School Science Fair jobs I've seen on eBay where they silicone it on sideways and add a bunch of wires or some Mickey Mouse outboard circuit board.

    I'll attach a few pics


    Here's the relay after modifying.
    You have to reverse the coil wires and the movable armature wires.
    [​IMG]

    I carefully unsolder the white wires and move them out of the way temporarily.

    The older relays in the Faultline Audio tutorial had flexible wires connecting the coil wires to the pins making it much easier but Omron changed to a solid coil to pin connection about 4 or 5 years ago so now you have to carefully cut the metal strap out between the coil wire stud and the pin.
    Once this is done I solder a insulated jumper wire from the coil wire stud over to the middle pin which in the 1200/240/250/250M relay circuit board is the coil feed.

    Then I solder the white armature wire to the back pin and repeat on the opposite side of the relay.
    [​IMG]
    Put the cover back on and you have a brand new unobtainable relay!

    To make it fit the board properly you have to slightly skew the pin holes so the smaller footprint relay will fit the existing holes.

    The only difficult part is taking your time and being very careful not to touch anything else with your soldering iron while working in the close confines of the relay.

    The finished look is well worth it!
    [​IMG]

    Bob
     
    Last edited: Mar 21, 2018
    MBuras, Aaron99, gogofast and 2 others like this.
  3. gogofast

    gogofast AK Subscriber Subscriber

    Messages:
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    Location:
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    Wow, thanks for posting the procedure.
    I'm not really familiar with the relay internals. I believe the below is the MY2-02 pin out. What pins am I swapping internally?

    my2-02.jpg
     
  4. wlhd1610

    wlhd1610 Penny and her new friend Subscriber

    Messages:
    2,343
    Location:
    upstate new york
    9&13
    12&14

    The coil feeds are pins 9 & 12 in the Marantz 1200/240/250 and 250M which use the Shrak(sp?) relay.

    Pins 1 & 4 are not used and just get in the way so I snip them off.

    Bob
     
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  5. gogofast

    gogofast AK Subscriber Subscriber

    Messages:
    7,920
    Location:
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    Ah, I get it now.
    This will help me and others looking to do the same in the future.
    Thanks again!
     
  6. MBuras

    MBuras Restoration is an Addiction Subscriber

    Messages:
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    Location:
    Champaign, IL
    Thanks so much to Bob @wlhd1610 for detailing this relay modification. I'm in process of rebuilding a 1200 and although the current relay is serviceable I wanted to challenge myself with soldering some small bits. It went quicker than I expected and I'm happy with the result. Glad I always save bits of scrap wire for times just like this. :thumbsup:
     
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  7. catrafter

    catrafter Marantz Specialist Subscriber

    Messages:
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    Location:
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    Thanks for documenting this, I was afraid it was lost when Chrismarantz's site went away.

    Tom
     
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