Humming in LM1036 Pre-amp (Tone Control) I built

Discussion in 'General Electronics Chat' started by lubnaan90, Feb 22, 2012.

  1. lubnaan90

    Thread Starter Active Member

    Jan 13, 2010
    196
    2
    Greetings To all,

    I recently built a Pre-amp Tone control board based on LM1036 Chip, For those who are interested in Making one i have attached a PCB, Schematics and a Part list in this Thread.

    Now, To the problem, I built the circuit, tested it, works fine except there is lot of Humming . When the Volume pot is maxed to 100% the humming becomes louder.

    I have used the best quality Shielded AV cables so i dont think it is because of the cables.

    Any Wise reply, comments or advises will be deeply appreciated.
     
  2. bountyhunter

    Well-Known Member

    Sep 7, 2009
    2,498
    507
    Likely hum from ripple in the power supply. Is the PCB sitting near the power transformer? That will make it hum.
     
  3. lubnaan90

    Thread Starter Active Member

    Jan 13, 2010
    196
    2
    Tried with three different regulated 12v Power supply, even tried with a 12volt Wall Adapter, Tried different location, Tried every thing. No Luck :(
     
  4. Audioguru

    New Member

    Dec 20, 2007
    9,411
    896
    R1 and R21 feed any hum and noise from the power supply directly into the inputs.
    R1 and R21 should be fed from a filter.
     
  5. bountyhunter

    Well-Known Member

    Sep 7, 2009
    2,498
    507
    That makes sense. You could try adding a small resistor inseries with the top of R1/R21 and then putting a decent sized electrolytic cap at the top of each R1/R21 to decouple the power supply ripple.
     
  6. mehrimran23

    New Member

    Feb 23, 2012
    3
    0
    i want to control a 12 v device with dc battery and 12 v dc adaptor. i have 5 pin 12 v dc relay. pls help to give me circuit diagram
     
  7. lubnaan90

    Thread Starter Active Member

    Jan 13, 2010
    196
    2
    Plz dont hack other member's threads, for any help or question's that are not related with this thread, start a new thread.
     
  8. H_BioMed

    New Member

    May 30, 2013
    5
    0
    Hi lubnaan90 Thank you for your review, but you try to simulate MiXer LM1036 in NATIONAL INSTRUMENTS Multisim if you do that Please Help me i can't creat the component becouse i'm not programing if you have the code or enything about it please give me
    Find me
    Twitter: @H_BioMed
     
  9. H_BioMed

    New Member

    May 30, 2013
    5
    0
    I will Upload Datasheet to LM1036 for members

    Thanx to All :rolleyes:
     
  10. GopherT

    AAC Fanatic!

    Nov 23, 2012
    6,069
    3,840
    H_BioMed,

    You raised an old thread from the dead. Last post was Feb 2012. I thing the OP has long forgotten this problem or found anther solution.
     
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