Finding Transistors - 2SA966A & 2SC2336

Discussion in 'The Projects Forum' started by vintage, Jan 29, 2013.

  1. vintage

    Thread Starter New Member

    Jan 29, 2013
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    I have an old guitar amplifier with constant hum (even when the volume is at 0). I tried replacing the PS filter cap and output cap but nothing changed. Putting a cap across the speaker leads tamed the hum, so I'm guessing its the output transistors.

    The two I need are

    2SA966A
    2SC2336

    Both are TO-92L cases.

    I'm having a hard time finding exact matches. Can anyone recommend a supplier of small (1 of each) quantities?

    Thank you
     
  2. absf

    Senior Member

    Dec 29, 2010
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  3. GopherT

    AAC Fanatic!

    Nov 23, 2012
    6,043
    3,807
    Hum often comes from ground loops (or a re-wiring error were ground is swapped with signal wire on the output jack or the pick-up). Crossing wires on the input of the amp also causes the same hum.
     
  4. wayneh

    Expert

    Sep 9, 2010
    12,120
    3,046
    I don't think the diagnosis follows from the test. (But I must admit ignorance.) All the cap does is absorb high frequencies, including a portion of the hum. You want the hum to be gone before it gets to the power transistors.
     
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