Marantz 4230 Transistor list anyone?

Discussion in 'Marantz Audio' started by slayer44, Jan 15, 2019.

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  1. slayer44

    slayer44 AK Subscriber Subscriber

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    Greetings!...has anyone recently rebuilt the amp boards in the 4230?...I was wondering if anyone had a spreadsheet handy to order from. I have a TON of Fairchild semiconductors and would prefer to use those, but if others are preferred, I'll use those. Thanks in advance.
     

     

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  2. slayer44

    slayer44 AK Subscriber Subscriber

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    Anybody?
     
  3. MBuras

    MBuras Restoration is an Addiction Subscriber

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    FYI It’s pretty uncommon to have recap lists in the Marantz forum. Mostly in the Pioneer forum and maybe a few in Kenwood or Sansui from my experience.

    If you’re looking to replace transistors (most will tell you not a good idea unless they’re known bad) then just use the AK search engine and cross reference the original part. There’s a million threads on various replacements.
     
  4. slayer44

    slayer44 AK Subscriber Subscriber

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    MBurras...thank for the advice...I am usually in the Pioneer forum and know a great deal about them...This is my first Marantz restoration, so I figured I had better go with what the Marantz folks used for parts. I have everything cross-referenced except I can't find a replacement for the 2SA641 and the 2SC684. Thanks for the input, though.
     
  5. MikeRam

    MikeRam AK Subscriber Subscriber

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    I was messing around on my 4230 and accidentally blew an output transistor so did some research on the replacements. Here is the information I gleaned. I forget what I ended up with. I'll pull my board out tomorrow and let you know.


    Output Transistors


    The correct replacement is a TIP31B TO-220
    Elsewhere others have suggested 2N6292 as a replacement.
    Hyperion


    2SC789 TIP31B 512-tip31b $.43ea. (end of life comments)
    Larry


    to-220
    q11,12 2sc789
    512-KSD526Y NPN to-220 bce 80v 4a 30w 3mhz 15-240hfe $0.62
    markthefixer

    I have used KSD526Y to replace 2SC789's in a 4230. In the supplements to the manual, Marantz recommended using 2SD315D's, but those are NLA. The specs are pretty close.



    Strange. I see in the schematic that the output transistors are supposed to be 2sc789 but the actual transistors in the amp are 2sd315 (as the one in the PS). Same TO-66 package.
    2sd315 E has a gain of 100-200 and the schematic calls for O-Y on 2sc789. O is a gain of 40-80 and Y is 120-240. And all 2sc789 I find on google are TO220 package. Strange indeed...



    The transistor is a Toshiba, the equivalent Sanyo is a 2SD313, Toshiba also had a 2SD526, NEC had the 2SD288 and Rohm had the 2SD1762.

    the 2SD526 is an 80v, 4A, 30watt, 3Mhz TO220.

    The original is a 70v,4A,30w, with BD241B,243B,579 and 589 all listed as equivalent.
     
  6. slayer44

    slayer44 AK Subscriber Subscriber

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    Thanks MikeRam...I am using TIP41C for my outputs and I am all set there. I was going to leave the transistors alone in P700 boards per some peoples suggestions, but after inspection, I found 6 burnt resistors, an exploded NTE??? where a 2SA641 is supposed to be, and a plethora of replaced components that don't look right. Somebody was in here before and they didn't know what they were doing. Instead of finding the correct value resistors, they would solder two together. It's a complete mess, so I decided to start from scratch.
     

     

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