volume control

Discussion in 'The Projects Forum' started by lowrise4, May 11, 2015.

  1. lowrise4

    Thread Starter Active Member

    Sep 6, 2010
    I'm doing a sound-maker project that will have several volume controls. Does it make any difference if I wire each potentiometer using only two terminals (as a variable resistor) or is there an advantage to using all 3 terminals? (voltage divider/potentiometer) . Somewhere long ago I read that having the third terminal connected to ground has some benefit.
  2. MrChips


    Oct 2, 2009
    You have answered your own question.
    A two-terminal potentiometer is a variable resistor.
    A three-terminal potentiometer is a voltage divider.
    There is a huge difference between the two.
  3. djsfantasi

    AAC Fanatic!

    Apr 11, 2010
    What do you mean by "several" volume controls?
  4. lowrise4

    Thread Starter Active Member

    Sep 6, 2010
    My project involves having eight 555 timers, each one making a different audio tone, triggered in sequence by a 4017 sequencer. I will need a lot of potentiometers to control the volume and frequency of each audio 555, the frequency of the 'clock' 555 that sends pulses to the 4017, as well as a master volume knob.

    In the past, every time I needed to control volume or signal level in a circuit, I used a potentiometer wired using only 2 terminals (middle and one of the outer ones) and it worked fine. Is this the correct way to control volume/level?
  5. AnalogKid

    AAC Fanatic!

    Aug 1, 2013
    If the pot is part of a gain control circuit, like the series feedback resistor in an opamp circuit, then it can function with only two connections as a variable resistor. If it is a true volume control, a variable attenuator that can take it's input signal all the say down to zero, then you need all three connections. Post a schematic of your previous connection ways and we'll comment.