Tips For Installing A Headphone Jack

Discussion in 'General Electronics' started by Larry G., Aug 17, 2003.

  1. Larry G.

    Larry G. Guest

    I just purchased a new Apex stereo TV/DVD combo with many bells &
    whistles EXCEPT a headphone jack. Have any of you readers been able
    to successfully install a stereo headphone jack into a stereo TV?
    Thanks.
     
    Larry G., Aug 17, 2003
    #1
    1. Advertisements

  2. Larry G.

    Rich Grise Guest

    (Larry G.) wrote in message news:<>...
    > I just purchased a new Apex stereo TV/DVD combo with many bells &
    > whistles EXCEPT a headphone jack. Have any of you readers been able
    > to successfully install a stereo headphone jack into a stereo TV?
    > Thanks.


    Yes, I have. One thing to watch out for is that both of the speakers'
    "ground" or "return" lines are common, i.e., electrically the same
    point. I forget what the jack is called, but it's got 5 terminals:
    The sleeve, obviously, which is the speaker common. Then it has two
    contacts which contact tip and ring, but they get their signals from
    the other contacts. When you push the plug in, it disconnects the
    speakers and goes to the phones.


    audio out o-------------------------\/
    ^
    | <<<---- plug
    o----------------+
    |
    |
    +---------------------------------> to speaker


    When you plug in the plug, it opens the contact. There are two of
    these circuits in the jack.

    Good Luck!
    Rich
     
    Rich Grise, Aug 19, 2003
    #2
    1. Advertisements

  3. Larry G.

    skipper

    Joined:
    Jun 24, 2009
    Messages:
    1
    Likes Received:
    0
    The simplest approach is to wire the headphone jack to the speaker outputs through an attenuating circuit. The things to be careful though is that the output amp circuit needs to be properly loaded in order to provide the correct audio response and to protect both the amp circuit and headphones from over-currents. The impedance expected by the amp and that expected by the headphones need to be accounted for to flatten the frequency response and minimize distortion and noise. Finally, it doesn't take much to drive headphones to painful levels:

    WARNING
    Headphones are rated in dB SPL at 1mW, and this circuit is capable of producing extreme SPLs. The levels obtainable are sufficient to cause almost instantaneous permanent hearing damage! Never operate the player at very high levels, and never switch the amplifier on with signal while wearing your headphones.

    Always start with the volume control at minimum, and gradually increase the level until it is comfortable, but not too loud. Because of the very low distortion, it is easy to increase the level too far without noticing. Your ears are precious - safeguard them at all times.


    That said, here is an article to calculate exactly what you need:
    sound.westhost.com/project100.htm
    and I attached it's circuit diagram:

    sound.westhost.com/p100-f1.png

    Here is a limiting circuit that you can wire between the above resisters
    and the jack itself to protect your ears:
    wa0itp.com/audiolimiter.pdf
     
    skipper, Jun 24, 2009
    #3
    1. Advertisements

Want to reply to this thread or ask your own question?

You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.
Similar Threads
  1. meanEG
    Replies:
    8
    Views:
    493
    hevans1944
    Aug 13, 2016
  2. crystal please
    Replies:
    2
    Views:
    473
    crystal please
    Jul 5, 2016
  3. Kennynva

    How to build a 455khz oscillator for a signal generator..

    Kennynva, Jul 14, 2016, in forum: General Electronics Chat
    Replies:
    12
    Views:
    1,473
    hevans1944
    Sep 21, 2016
  4. James Watt

    A simple question on 2.5mm headphone jack

    James Watt, Jul 20, 2016, in forum: Electronics Repair
    Replies:
    3
    Views:
    228
    shrtrnd
    Jul 20, 2016
  5. SickSquirrel

    I need a charger for a power bank ...

    SickSquirrel, Aug 5, 2016, in forum: General Electronics Chat
    Replies:
    11
    Views:
    351
    SickSquirrel
    Aug 8, 2016
  6. rogervan
    Replies:
    11
    Views:
    440
    Sunnysky
    Aug 12, 2016
  7. Rob Pearson

    Best way to get a replacement part for a switch?

    Rob Pearson, Sep 8, 2016, in forum: General Electronics Chat
    Replies:
    5
    Views:
    327
    73's de Edd
    Sep 10, 2016
  8. jls667
    Replies:
    3
    Views:
    304
    duke37
    Sep 15, 2016
Loading...