Amp Hum Valvestate S80

Discussion in 'The Workbench' started by James McC, Jan 9, 2017.

  1. James McC

    James McC New Member

    Joined:
    Jan 9, 2017
    Messages:
    2
    Likes Received:
    0
    I've got a Marshall Valvestate S80 Model 8240. This has developed quite a loud hum whether instrument connected or not. However I've noticed when I tip the amp forward far enough the hum disappears.

    Can anyone advise what the issue might be and how to get rid of the hum when its upright?
     
  2. ampmadscientist

    ampmadscientist Well-Known Member

    Joined:
    Jun 26, 2014
    Messages:
    4,552
    Likes Received:
    1,592
    Location:
    In your bathtub.
    It can be a bad connection inside, or it could be a blown output transistor...
    You gotta just open it up and see what's up w/ it.
     
  3. James McC

    James McC New Member

    Joined:
    Jan 9, 2017
    Messages:
    2
    Likes Received:
    0
    Thanks I will have a look, but I'm not entirely how to get into it.
     
  4. ampmadscientist

    ampmadscientist Well-Known Member

    Joined:
    Jun 26, 2014
    Messages:
    4,552
    Likes Received:
    1,592
    Location:
    In your bathtub.
    It's like a capacitor that broke loose from the circuit board, and you need to re-solder it.
    There are usually 4 big screws on the bottom of the box, take those out and slide the amp out of the cabinet.
    You can do it for sure.
     

Share This Page