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audio transistor schema...

Discussion in 'Audio' started by tedstruk, Mar 1, 2017.

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  1. tedstruk

    tedstruk

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    Jan 7, 2012
    I am thinking about the signal flow in my circuits...
    is it better to use the collectors on the transistors for the input signal ----
    and
    the emitters on the transistors for output signal?

    or is it arbitrary and the flow of the shema has little to do with proper flow of the signal?
     
  2. tedstruk

    tedstruk

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    Jan 7, 2012
    What does OCE on a transistor mean? I can't find a 608 OCE transistor on any datasheets anywhere.
     
  3. Audioguru

    Audioguru

    2,742
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    Sep 24, 2016
    Please learn about transistors from a book or from a tutorial in Google.
    A transistor can be common emitter when the base is the input and the collector is the output with lots of voltage and current gain. A transistor can be common collector when the base is the input and the emitter is the output with lots of current gain but a voltage gain of only 1. A transistor is rarely used as common base when the emitter is the input and the collector is the output. The collector is NEVER used as an input.

    Most American transistors are 2Nxxxx like a 2N3904 transistor. Many European transistors are BCxxx like a BC547 little transistor or BDxxx like a BD139 power transistor. Many Japanese transistors are 2SCxxx like a 2SC945 transistor. OCE are three letters that mean nothing to me, maybe you mean the Vceo maximum collector to emitter voltage allowed for a transistor when its base is open (disconnected)?
     
  4. tedstruk

    tedstruk

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    Jan 7, 2012
    The Words > 608 OCE are printed on the round backside, of a little plastic, three pin component, that is flat on the front side. I think this is the proper identification of a transistor thing.

    Maybe they are some of those bogus components made in the 80's?
     
  5. 73's de Edd

    73's de Edd

    2,805
    1,176
    Aug 21, 2015
    Sir tedstruk . . . . . .

    I already have those transistors propery identified and already placed on a new schematic that I am creating for that unit.

    HOWEVER In the GREAT change up and deletion of your first posting, I seem to no longer have access to the photo of the COMPONENT side of the PCB, however I do have 2 good ones of the PCBs .foil side.
    If your first photos covered the component side nicely , can you re post it again ?

    OR if you have to make another, be sure that the board is well lit, straight on / no parallax and is squared up in the viewfinder as an almost full picture frame closeup .

    Thasssssit . . . . .

    73s de Edd
     
  6. tedstruk

    tedstruk

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    Jan 7, 2012
    I want you to know how much I appreciate this help. I am kind of stuck with this old thing. I can't find any of the datasheets, It wasn't the type I thought it was when I got it, and I can't find any wiring diagrams or schematics for the board.

    I am finally learning alot of electronics!
     

    Attached Files:

  7. tedstruk

    tedstruk

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    Jan 7, 2012
    I posted a pic of the board and I wanted your opinion on these 608 OCE transistors...
    could the OCE stand for O=common C=Collector E=Emitter, the 608 may have been a size and style being plastic flat on one side... Is there a way to test these to see which is the emitter and which is the collector?
     
  8. tedstruk

    tedstruk

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    Jan 7, 2012
  9. davenn

    davenn Moderator

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    Sep 5, 2009
    no, not likely
    is there nothing written on the flat side ?
     
  10. tedstruk

    tedstruk

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    Jan 7, 2012
    switch off, Treadle and input are going through Pin F...
    treadle is full up
     

    Attached Files:

  11. tedstruk

    tedstruk

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    Jan 7, 2012
    switch off, treadle full down(off) up is, fully on
     

    Attached Files:

  12. tedstruk

    tedstruk

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    Jan 7, 2012
    Switch On, full up(on)1.75v, and full down(off)1.55v
     

    Attached Files:

  13. tedstruk

    tedstruk

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    Jan 7, 2012
    ...nothing else written...
     
    davenn likes this.
  14. tedstruk

    tedstruk

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    Jan 7, 2012
    so you guys are all headed for the 'solid state dead end"?
    solid state is supposed to plug into ISA...
    It was designed to add components or change small errors in circuits designed and created by computers.... before they made computers that were perfect.
    Then all at once... somebody had a brain storm..
    ''let's build solid state circuits right on the printed circuit board''
    and everything went arduino...
    The rest of us went to steves for beer.
     
  15. tedstruk

    tedstruk

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    Jan 7, 2012
    PS. Smeltzer is dead...
     
  16. (*steve*)

    (*steve*) ¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd Moderator

    25,305
    2,738
    Jan 21, 2010
    What are you smoking? Your posts don't make any sense.
     
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