Linn Karin preamp problem

Discussion in 'Hi-Fi and General Audio' started by nj1024, Aug 12, 2015.

  1. nj1024

    nj1024

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    Please help!!

    I have a problem with my Linn Karin. Sometimes I hear a loud thundering sound through the speaker. after a few second, it disappears and then comes back. I think the problem with the preamp cause I tried a different preamp and this thundering sound does not happen. This has been now happening for about 3 months.

    My preamp was last serviced 2005. At this time the power supply and motherboard were replaced. I have a slimline power supply.

    Has anybody else had this issue? How did you do to resolve it?
     
    nj1024, Aug 12, 2015
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  2. nj1024

    mjp200581

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    I've not heard of that exact problem before but if it was my Kairn I'd replace the electrolytic capacitors inside the Brilliant power supply. These capacitors wear out over time and cause the power supply to fail which a a common problem. My money would be on a failing PSU.

    It would be prudent to replace them with 105C temp rated caps with the longest lifetime specs you can find.

    While you've got the Kairn apart it would also be a good idea to replace the mempac battery located on the front panel PCB if that's never been done before as they can leak and damage the PCB.

    Do you leave it powered up 24/7?
     
    mjp200581, Aug 14, 2015
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  3. nj1024

    nj1024

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    Hi, Thanks for reply .My kairn had brillant power supply it was sent to scotland to and had slimline psu installed and at the same time main board was also changed.It ran good and sound very good till this problem started about few months ago.Yes I left the pre amp on 24/7? You thaink that the psu is the problem.I had the psu out it has 2 x jamicon 390uf 200v capacitors and 6 x jamicon 100uf 35v capacitors.I am able to replace those capacitors which one you recommend it has to the same size because there is no room inside the psu.I love this amp.I need help?
    My system is :-
    LP 12 ,Lingo,Ekos ,Arkiv
    Linn Isobarik
    Lin aktiv crossover
    6x mono blocks
     
    nj1024, Aug 16, 2015
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  4. nj1024

    mjp200581

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    If your Kairn has been left powered up 24/7 for the last decade then it's entirely possible that the electrolytics inside the Brilliant need replacing. If you're confident in your ability to replace them then I'd definitely do it, it'll probably only cost you £10 or so and could solve the problem.

    You want to fit 105C rated capacitors with a long service life and I'd stick to the well known brands. Off the top of my head Panasonic FM or Rubycon YXF might be a good choice for the lower voltage ones. The search function on the Farnell website is excellent and will give you all of the information you need to select suitable replacement parts.

    Personally I always switch off all of my equipment after use to prolong its life. If I know I'm going to be settling down for some really serious listening I simply turn on everything an hour before to give it all chance to warm up first.

    If you are near Sheffield I'd be happy to help.
     
    mjp200581, Aug 16, 2015
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  5. nj1024

    nj1024

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    Thanks for your advise i have order caps for the power supply i will install them when they come.Please advise me should I recap the kairn? I was thinking the rest of the capacitors may be defective or getting weaker.I know that this job is a big job what i can do it.What you think I need recap at this time.Please tell me if i have to recap what kind of caps i need to buy
     
    nj1024, Aug 19, 2015
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  6. nj1024

    mjp200581

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    I replaced all of the small electrolytics on my own Kairn a couple of years ago and I did think I got a small boost in sound quality afterwards.
    I've always had good results when using Rubycon ZLH and YXF and Panasonic FM, FC or NHG.
    It's the caps inside the PSU which get the most hammer but if you feel confident replacing the rest then why not.
    I definately recommend you replace the mempac battery if it's never been done!
     
    mjp200581, Aug 19, 2015
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  7. nj1024

    nj1024

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    I remove the cover off and i notice three different size tantalum caps i can read the value of these caps.Any way knowing the caps what they are or any body replaced these caps please help.I can read the other caps they are rubycon caps 22uf 50v and 220uf 16v
     
    nj1024, Aug 20, 2015
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  8. nj1024

    mjp200581

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    I wouldn't worry about replacing the tantalum caps as they don't have a wet electrolyte which dries out like in a regular aluminium electrolytic.

    I'd love to get a schematic to find out what the function of these tantalum caps is though to see if they are likely to have any effect on sound quality.

    The mempac battery is located on the front panel. They have a tendency to leak and damage the PCB so please check it! They're very easy to replace.
     
    mjp200581, Aug 21, 2015
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