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    Loud pop when turning off MK-III monoblocks?

    ViperZ
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    Post by ViperZ on Mon Jun 18, 2018 9:21 pm

    I hope that would be my last question for a bit...

    When I turn off either of my rebuilt MK-III monoblocks with the power switches, I get a sharp pop/chirp through the speakers. When I turn them off from the power bar, I don't get this problem. Is there an "easy fix" for this? Thank you.
    peterh
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    Post by peterh on Tue Jun 19, 2018 3:02 am

    ViperZ wrote:I hope that would be my last question for a bit...

    When I turn off either of my rebuilt MK-III monoblocks with the power switches, I get a sharp pop/chirp through the speakers. When I turn them off from the power bar, I don't get this problem. Is there an "easy fix" for this? Thank you.
    Install a snubber cap across the switch ( a cap with a built-in series resistance).
    Or, don't use the built-in, the power bar is more convenient.
    Or, install a SSR ( solid state relay ) and control the relay with a small DC from preamp.
    ViperZ
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    Post by ViperZ on Tue Jun 19, 2018 11:10 am

    Peter W.
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    Post by Peter W. on Tue Jun 19, 2018 11:30 am


    That will do it - it has the proper X rating for line-to-neutral.

    I am surprised ones were not supplied OEM.
    ViperZ
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    Post by ViperZ on Tue Jun 19, 2018 11:42 am

    Thank you both.
    I would have installed the caps, but I got confused when I was rebuilding the amps. There is already a disc capacitor (the 0.02 one), and for some reason I thought that it's the same cap, which is obviously not the case. I will open both amps and put the caps in, hopefully I won't have this annoying pop after that Smile
    tubes4hifi
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    Post by tubes4hifi on Tue Jun 19, 2018 12:36 pm

    snubber caps should always be connected across an AC power switch, this is a photo from my SP14 preamp builds.
    Loud pop when turning off MK-III monoblocks? SP14-258
    Kramer
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    Post by Kramer on Wed Jun 27, 2018 5:25 pm

    Thanks for this post, I had a similar issue with a annoying pop when powering off my amp. A snubber cap did exactly as described.
    ViperZ
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    Post by ViperZ on Wed Jun 27, 2018 5:30 pm

    Loud pop when turning off MK-III monoblocks? Img_2011
    ViperZ
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    Post by ViperZ on Wed Jun 27, 2018 7:19 pm

    I still get a soft pop sometimes, but nowhere near nasty harsh chirp I used to get.
    Peter W.
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    Post by Peter W. on Thu Jun 28, 2018 11:18 am

    Is that a Klabunde etching in the picture?
    peterh
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    Post by peterh on Thu Jun 28, 2018 11:23 am

    Using an SSR instead of a mechanical switch eliminates switch noice as they make or break at zero
    crossing. In addition one get a remote control possibility.
    ViperZ
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    Post by ViperZ on Thu Jun 28, 2018 12:47 pm

    Peter W. wrote:Is that a Klabunde etching in the picture?

    It's a record cover Smile. I'll take a photo of it when I'll get home.
    pichacker
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    Post by pichacker on Fri Jun 29, 2018 2:51 am

    Assuing thats a suitably rated cap or snubber you've used Smile
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    BryceJ

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    Post by BryceJ on Mon May 06, 2019 4:10 am

    tubes4hifi wrote:snubber caps should always be connected across an AC power switch, this is a photo from my SP14 preamp builds.
    Loud pop when turning off MK-III monoblocks? SP14-258

    What value of device or part number would you suggest for an M-125 Monoblock power switch?
    tubes4hifi
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    Post by tubes4hifi on Sat May 11, 2019 3:00 pm

    the capacitor I've been using the past ten years is no longer available, so I did a fresh search, and came up with these results at Mouser . . .
    https://www.mouser.com/ProductDetail/Vishay-Cera-Mite/20VLS10-R?qs=%2Fha2pyFaduhVvpzkhtAh0j%2Fcg0Vvecky3JZvYXRf%252Bdk%3D
    https://www.mouser.com/ProductDetail/Vishay-BC-Components/S103M69Z5UP63K7R?qs=sGAEpiMZZMuMW9TJLBQkXp4eEQ3KTPcv0%252BSLvNIe0A4%3D
    this are class X2 capacitors, intended to be placed across a AC power switch, usually rated at 0.01uF and 2000vdc, or 400vac, ceramic disc
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    BryceJ

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    Post by BryceJ on Sat May 11, 2019 3:52 pm

    tubes4hifi wrote:the capacitor I've been using the past ten years is no longer available, so I did a fresh search, and came up with these results at Mouser . . .
    https://www.mouser.com/ProductDetail/Vishay-Cera-Mite/20VLS10-R?qs=%2Fha2pyFaduhVvpzkhtAh0j%2Fcg0Vvecky3JZvYXRf%252Bdk%3D
    https://www.mouser.com/ProductDetail/Vishay-BC-Components/S103M69Z5UP63K7R?qs=sGAEpiMZZMuMW9TJLBQkXp4eEQ3KTPcv0%252BSLvNIe0A4%3D
    this are class X2 capacitors, intended to be placed across a AC power switch, usually rated at 0.01uF and 2000vdc, or 400vac, ceramic disc

    Thanks for the information. I found a lot of safety capacitors, but I found it very difficult to find any recommendations on suitable values. This makes it much easier.

    One comment. I don't see the X2 class rating for the S103M69Z5UP63K7R capacitor, just class 2 rating. The other capacitor is clearly marked as an AC line rated capacitor, class X2.

    Cheers.


    Last edited by BryceJ on Sat May 11, 2019 3:52 pm; edited 1 time in total (Reason for editing : Spelling)

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