Bad Sound in Audio amp

Discussion in 'The Projects Forum' started by Saitam, Feb 24, 2008.

  1. Saitam

    Thread Starter New Member

    Feb 11, 2008
    5
    0
    Hi,

    I have built a basic audio amplifier for aplification of audio singnals from a mp3 player or other small power output. But the sound is very unpure. I am not going over the max. Gain. Or other max. limit. May it be that I am useing wrong type of capasitors? I have heard that it matters but I don't know what type I must use. I have tryed stabilising the V.input put that dosen't help eighter.May it be that I am useing bad cables.

    Here is the schematic I am useing the example circuit "Amplifier with Bass Boost" on page 5

    http://www.futurlec.com/Linear/LM386N-3.shtml

    Thanks
     
  2. Audioguru

    New Member

    Dec 20, 2007
    9,411
    896
    Your little amplifier is probably clipping because its volume control is turned up too high for its low amount of available power. Clipping causes severe distortion.

    The little LM386 amplifier IC has a very low max output power. Without bass boost its power at clipping into an 8 ohm speaker with a 9V supply is only 450mW. The bass boost means that mid-range and high audio frequencies must be reduced to a max power of only 112.5mW so that the bass frequencies don't clip which is almost no power. A cheap clock radio produces 1W.

    If you used a 5W amplifier then it will sound only twice as loud. A 10W or 20W amplifier would probably work fine then you can keep its volume turned down so it doesn't clip.
     
  3. Saitam

    Thread Starter New Member

    Feb 11, 2008
    5
    0
    Thanks allot I'll try that, btw. I used a 9V power supply.
     
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