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Loud buzzing from AC30CC2X w/ no volume

Discussion in 'Amp Tech Center' started by Strat-tastic, Mar 19, 2021.

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  1. Strat-tastic

    Strat-tastic TDPRI Member

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    Hey guys, My vox ac30 has essentially been a paperweight for the last few months due to a loud buzzing sound emitting from the amp’s speakers, regardless of volume. I’m including a picture of what I think the problem might be (but I don’t even know what it is I circled to be honest). You can check out a video of the sound here:
    If you guys could give any suggestions I’d be forever thankful, because I love this thing. Cheers!


    C114AA3C-29A8-43ED-B415-C6910A1AFCF9.jpeg
     
  2. Jon Snell

    Jon Snell Tele-Holic

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    That is the mains transformer.
    Check the screws are tight and the fibre washers are insulating properly.
     
  3. dan40

    dan40 Friend of Leo's

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    It's not uncommon for a power transformer to hum or vibrate a bit but this noise should not be coming through the speaker. With the back panel off the circuit is unshielded and holding a camera close to it will cause the level of noise to increase. If the amp is not working properly when you are plugged in and playing then you have an issue with the circuit that will likely require a tech to diagnose.
     
  4. gusfinley

    gusfinley Tele-Afflicted

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    Is the mains transformer vibrating? Is it warm/hot?

    This defintitely does not sound good!

    What sort of tools or confidence do you have to debug?

    Do you use the standby switch at all?
     
  5. Strat-tastic

    Strat-tastic TDPRI Member

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    I used to use standby, but I already had issues with the amp dying on me, and the tech who repaired the amp said that I should just flip em both and go to work.. I’m not sure if the transformer is vibrating as I’m pretty weary of poking around and getting lit up. I was basically just looking for some advice on whether this is in my realm of experience, but, I think I’m just gonna take it to a tech at this point.
     
  6. gusfinley

    gusfinley Tele-Afflicted

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    Sounds like a good idea if your wary of touching a transformer!
     
  7. Bendyha

    Bendyha Friend of Leo's Silver Supporter

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    There was a series in the English magazine Everyday Electronics back in 1978, sort of a chat story with a tech and some young guys, about Vox AC30's and the circuit. Probably won't solve your problem, but might be of interest to you anyway.
     

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