Marantz 2215B P700 question

Discussion in 'Marantz Audio' started by lebrun53, May 18, 2017.

  1. lebrun53

    lebrun53 New Member

    Messages:
    5
    Location:
    Montreal, Canada
    Hello all,
    Looking to AK for a solution to a problem I am having.
    On the P700 amp board there are two "lamps" (M701 & M702 / IN1006035 lamp, 6v).
    They appear to be ballast for the PNP output's bias (H709 & H710)
    The board I am servicing is missing one.
    The current draw on the one I do have is about 89ma at 6v
    A regular 6v bulb with a 40ma draw does not appear to work.
    Is this more than a "lamp"?
    Is there a replacement for this piece?
    Can I use a pot instead of the lamp?

    Thanks in advance.... you guys are great.

    Larry
     
  2. catrafter

    catrafter Marantz Specialist Subscriber

    Messages:
    5,848
    Location:
    Montana
    I believe a lamp is used here because of it's negative resistance characteristics.
    I had some 6V 90mA lamps from years ago that I have used successfully in this application.
    A T1-3/4 size, 6 to 6.3V, 70 to 90mA lamp should work, JKL 7377 ( 6.3V 75mA) is readily available.
    You may want to replace the one in the other channel for symmetry.
    YMMV

    Tom
    .
     
  3. lebrun53

    lebrun53 New Member

    Messages:
    5
    Location:
    Montreal, Canada
    Thanks, Tom, for that information.
    I'll give that a try.
    Larry
     

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