Transformer humming

justshoemarkjustshoemark
in Amplifiers
Hi all. 
I no not many people on hear like bang Olufsen but I dont mind it.
I have a beomaster 4000 and it has very bad transformer hum. 
How easy is it to rectify this? 
Many thanks Justin

Comments

  • cj66cj66
    It's a known problem on the aging 4000 and 3000 units.
    The cure was to find an equivalent transformer that will fit or do a toroidal conversion.
    An old colleague of mine worked in a B&O service centre up until a few years ago and did the conversion on these. The other problem was the slider controls wearing out.
    The older B&O stuff was actually rather good and stylish to boot.
    I've always been tempted to get a nice console style music centre, my parents had a very stylish Philips which still looks good today ( not their actual one as it died ).



  • justshoemarkjustshoemark
    Thanks for the reply. 
    I have seen some me posts of people fitting a toroidal transformer but I'm not sure if I can do that not sure I have the skills. 
    Many thanks Justin
  • justshoemarkjustshoemark
    Well I just took the lid off and the transformer has been put in some resin before. So would probably need to put a new one in. Deep joy. 
  • DocfosterDocfoster
    A DC blocker / filter may help.
    It does quieten the transformers in my system.
  • AntiCrapAntiCrap
    Here is a DC blocker circuit that works well. ( look down the page)
    https://seca.freeforums.net/search/results?captcha_id=captcha_search&what_at_least_one=dc+blocker&who_only_made_by=0&display_as=0&search=Search

  • justshoemarkjustshoemark
    Thanks Colin hope you are keeping well. 
    I don't get a gun through the speakers it's the transformer that hums. It seems to be comman on this. I have took out the transformer and put it on some think foam and it has help.   
  • DocfosterDocfoster
    To clarify...The DC blocker quietens the transformer. No problem with the speakers.
  • justshoemarkjustshoemark
    Really that's interesting. 
    I'm not sure I could build one a put in n to a system. I'm not that good a doing these things wish I was. 
  • justshoemarkjustshoemark
    Well I have put the transformer in a separate box and have half the humming or buzzing. 
    Is there any one on here who would have a look at it for me please ?  
  • DocfosterDocfoster
    edited June 2020
    Really that's interesting. 
    I'm not sure I could build one a put in n to a system. I'm not that good a doing these things wish I was. 
    You can buy them ready made.
    They just plug into the mains and you plug your amp / system into them.
    Something like this.

    I don't usually recommend things, but I think it's worth giving it a go.
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