DIY PreAmp Ground Noise/Loop/Hum/Buzz/Distortion

Discussion in 'The Projects Forum' started by Vipul Kumar 1, Oct 20, 2018.

  1. Vipul Kumar 1

    Thread Starter Member

    Oct 20, 2018
    75
    2
    https://www.google.co.in/search?biw...3.4.275....0.sgAZZgjwMX8#imgrc=kif2vpqE6F0XQM:

    i made and pre amp using the above schematic but the problem is too much ground noise //buzz//hum//distortion even with connecting the output to the laptop and problem increases even more when i put my laptop on charging.
    is there any one here who can make this above schematic noise free distortion free make its sound clean and loud ,because i search many websites but did not get any solid solution for that you guys are my last hope pls send the modifies schematic of mine WhatsApp Image 2018-10-14 at 8.20.30 PM.jpeg
     
  2. bertus

    Administrator

    Apr 5, 2008
    19,663
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    Hello,

    What do you use to power the preamp?
    Perhaps the noise is coming from the powersupply.

    Bertus
     
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  3. Vipul Kumar 1

    Thread Starter Member

    Oct 20, 2018
    75
    2
    usb port of pc
     
  4. Vipul Kumar 1

    Thread Starter Member

    Oct 20, 2018
    75
    2
    audacity result.jpg
    here is the audacity result
     
  5. Vipul Kumar 1

    Thread Starter Member

    Oct 20, 2018
    75
    2
    Sir pls help me out
     
  6. ericgibbs

    Moderator

    Jan 29, 2010
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    hi,
    I would add some power line decoupling for starters, the USB power is noisy.
    E
    WhatsApp Image 2018-10-14 at 8.20.30 PM.jpeg
     
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  7. Vipul Kumar 1

    Thread Starter Member

    Oct 20, 2018
    75
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    will this modified schematic remove all the noise????
     
  8. bertus

    Administrator

    Apr 5, 2008
    19,663
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    Hello,

    Here is some additional decoupling for the mic itself:

    Vipel_preamp_filter.jpeg

    Bertus
     
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  9. ericgibbs

    Moderator

    Jan 29, 2010
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    hi,
    It is something I would always have in a preamp, especially a USB powered version.
    Decoupling is standard practice in most analog projects.
    E
     
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  10. bertus

    Administrator

    Apr 5, 2008
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    Vipul Kumar 1 likes this.
  11. crutschow

    Expert

    Mar 14, 2008
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    It should significantly help, but no one can predict if it will remove "all" of the noise, since there could be other noise sources we aren't aware of.
     
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  12. MrChips

    Moderator

    Oct 2, 2009
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    For a simple test, use a 9V battery for the power supply.
     
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  13. Vipul Kumar 1

    Thread Starter Member

    Oct 20, 2018
    75
    2
    If you hv anything in your mind that can be added to my schematic so that it can give a clean signal pls do share the modified schematic of mine
    Thank you
     
  14. Vipul Kumar 1

    Thread Starter Member

    Oct 20, 2018
    75
    2
    I tested with 9v battery but same is happening signal is very good but the noise is too much and very annoying when more when i use my amp in laptop on charging mode
    Pls try my schematic on your breadboard and try to find a permanent solution for this problem
     
  15. MrChips

    Moderator

    Oct 2, 2009
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    The problem is not with the circuit. The noise is AC pickup. You need to shield the entire circuit and use a shielded cable going into the laptop (and use a 9V battery).
     
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  16. Vipul Kumar 1

    Thread Starter Member

    Oct 20, 2018
    75
    2
    Thank for your active support Bertus Sir i will try every solution given by you and let you know mean while i am requesting you to try schematic setup on your breadboard if you find that noise is gone after your modifications do share that fina schematic with the change
     
  17. Vipul Kumar 1

    Thread Starter Member

    Oct 20, 2018
    75
    2
    Thank you ericgibbs sir i will try the solution given by you and let you know
     
  18. Vipul Kumar 1

    Thread Starter Member

    Oct 20, 2018
    75
    2
    I am requesting you to try the schematic on your bread board and share the corrected schematic
     
  19. John_2016

    Member

    Nov 23, 2016
    55
    5
    Hi Kumar

    I don't think they will do it for the fact that they have solved your question supplying a working circuit,
    therefore you are expected to test it and whether report back that it works, question solved, nice, or
    it doesn't work yet, the reasons being this and that ..

    If you have access to a college or uni electronics lab, could you just get the components and build the circuit?

    do you have a breadboard?

    regards

    John BG
     
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  20. Vipul Kumar 1

    Thread Starter Member

    Oct 20, 2018
    75
    2
    Yes I have bread board do have any solution ???????
    actually i dont hv coz i am not a engineering student
    i am commerce graduate in accountancy
    this project i took for my self to make a good preamp for my laptop
     
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