volume control on amp

Discussion in 'The Projects Forum' started by ligeowner66, Aug 22, 2014.

  1. ligeowner66

    Thread Starter New Member

    Aug 22, 2014
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    hi i just made my first project with the tda 2003.But i dont know were i must put the pot so i can control tha volume.I used this schematic.
     
  2. to3metalcan

    Member

    Jul 20, 2014
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    C1 to pot terminal 1, pot terminal 2 (wiper) to pin 1, pot terminal 3 to ground will work. What's the TDA amplifying??
     
  3. ligeowner66

    Thread Starter New Member

    Aug 22, 2014
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    thank you
    this moment my mobile phone but i might try it with a guitar.
    It should work right?
     
  4. to3metalcan

    Member

    Jul 20, 2014
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    Guitars need to see a high input impedance...1MΩ or more. If your pot is less resistance than that, it might work, but it won't sound good. The TDA may also not provide enough gain to make the guitar loud...you can solve both problems by adding a simple op-amp stage before C1.
     
  5. ligeowner66

    Thread Starter New Member

    Aug 22, 2014
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    have you something simple to suggest?
     
  6. ScottWang

    Moderator

    Aug 23, 2012
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    This was wrong.
    Pot volume control : if the left number is pin 1 then the middle is pin 2, and the right is pin 3, the pin 1 connecting to GND, so when you turn to the left side, the sound will be weak, the pin 2 connecting C1, the pin 3 is the input, so when you turn to the right side then the sound will be loud.
     
  7. ScottWang

    Moderator

    Aug 23, 2012
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  8. ligeowner66

    Thread Starter New Member

    Aug 22, 2014
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    so

    1->in
    2->c1
    3->ground

    right?
     
  9. ScottWang

    Moderator

    Aug 23, 2012
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    If the pins according to what I linked and you doing that then when you turn to the left side, the sound will be loud, turn to the right side the sound will be weak.
     
    Last edited: Aug 25, 2014
  10. ligeowner66

    Thread Starter New Member

    Aug 22, 2014
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    no prob,i like it this way

    can i use this as an op-amp?
     
  11. ScottWang

    Moderator

    Aug 23, 2012
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    Why you want to use LM386 as an op-amp?
     
  12. ligeowner66

    Thread Starter New Member

    Aug 22, 2014
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    then what to use?
     
  13. to3metalcan

    Member

    Jul 20, 2014
    228
    23
    The LM386 is a power amp. It doesn't have a high input impedance (at least, compared to op-amps) because it has built-in 50KΩ resistors. Try a TL071 or TL072...they're the common choice for guitar circuitry and usually work well.
     
  14. alfacliff

    Well-Known Member

    Dec 13, 2013
    2,449
    428
    a lot of discussion of wherfe to put the pot, but not any on the pot. it should be a log taper pot, linear taper pots change resistance differently, half total resistance in the center, log taper pots have their resistance tapered to more suit the sensativity of the human ear.
     
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