STK-0050 replacement for SX-780 and others

Discussion in 'Pioneer Audio' started by rcs16, Jun 18, 2016.

  1. rcs16

    rcs16 Super Member

    Messages:
    2,674
    Location:
    Baldwin, Ontario, Canada
    If you want to start up a new thread, in the Fisher section, I can offer some optional improvements to this design.
    I looked a bit at this manual, there are two obvious mistakes, in the table on p13/17 they state 1.2V from the emitter R's to ground.
    and the schematics on p15/17 that the ops emitter bias is 1.2V across both 0.22 ohm emitter resistors :bs:
    It should be more like 12mV across both emitter R's for a 27mA of bias current.
     
    Last edited: Mar 25, 2017
  2. Bassblaster

    Bassblaster Super Member

    Messages:
    1,474
    Location:
    Cambridge, Ohio
    Yes i was thinking about starting up its own thread. it may be a big project...
     
  3. merlynski

    merlynski AK Subscriber Subscriber

    Messages:
    19
    Location:
    High Plains, Eastern Colorado
    I would like two PCBs please, have a SX-780 with a dead channel. Let me know when you are ready to pass them on..
    Thanks, merlyn
     
    Last edited: Mar 29, 2017
  4. zebulon1

    zebulon1 Into Phase Linear's lately Subscriber

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    3,582
    Location:
    Las Vegas Nevada
    They should be here in a week or so.
     
  5. marshman

    marshman AK Subscriber Subscriber

    Messages:
    51
    Location:
    Sewanee, TN
    Zeb, I would be interested in a pair of boards if you still have a couple available.

    Thanks,

    mm
     
  6. HBrown

    HBrown AK Subscriber Subscriber

    Messages:
    277
    Location:
    South Georgia
    I have been thinking of putting a post in the Fisher section as well for the two fisher units I put them in- but I figured if anyone searched key words it would bring them here- where all the STK replacement info is anyway.
     
  7. rcs16

    rcs16 Super Member

    Messages:
    2,674
    Location:
    Baldwin, Ontario, Canada
    I have no issue, there are already postings here referencing Fisher units and the subject title does say "others". Kinda arbitrary where this thread is positioned in AK. I think it is better to have all the info in one place vs scattered about.
    BTW, pcbway has dropped their prices down to $5/10, what a deal they offer us DIY's. Happy Easter Eggs.
     
  8. Awesomeaudio

    Awesomeaudio AK Subscriber Subscriber

    Messages:
    698
    Location:
    Sydney, Australia
    Wow Rick. 6,945 views. Praises to you and your right hand man for this. Happy Days.
    I recently acquired a very very original one owner 780 and it is mint. I mean MINT.
    I cannot pick a single flaw on this baby cosmetically. It's drool worthy.
    If, and If I need to do the upgrade, I won't hesitate to buy your kit.
    Until then, hopefully the Original STKs keep.
     

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