Techie query for audio buffs

Discussion in 'Hobbies' started by magicsurfbus, Feb 19, 2015.

  1. magicsurfbus

    magicsurfbus Funster

    Joined:
    Oct 11, 2010
    Messages:
    3,507
    Likes Received:
    8,261
    Location:
    NW England
    I've picked up an old pair of Amplivox Audiocups industrial headphones in a pile of old tat, and would like to try them out on devices with a 3.5mm stereo output socket (eg a computer), if possible.

    Each ear cup has a 1/4" (6.35mm) mono plug so I need two sockets that will split the signal from a single 3.5mm stereo output plug.

    Does such a thing exist or will I need some kind of black box doohickey in between to boost or convert the signal?
     
  2. Bailey58

    Bailey58 Funster Life Member

    Joined:
    Jun 23, 2010
    Messages:
    6,376
    Likes Received:
    9,657
    Location:
    Norfolk and Toftir.
    • Like Like x 1
  3. magicsurfbus

    magicsurfbus Funster

    Joined:
    Oct 11, 2010
    Messages:
    3,507
    Likes Received:
    8,261
    Location:
    NW England
    Unfortunately not, but thanks for looking - that gizmo is for stereo input only, it doesn't work the other way.
     
  4. pappajohn

    pappajohn Funster Life Member

    Joined:
    Aug 26, 2007
    Messages:
    29,475
    Likes Received:
    16,957
    Location:
    YO11 2BD
    I think you are wrong....

    Plug the 3.5mm pin into your sound source and plug the headphones into the 6.5mm sockets.

    Its only a splitter taking one side of the stereo 3.5 to one of the mono 6.5 socket and the same with the other side..
     
  5. pappajohn

    pappajohn Funster Life Member

    Joined:
    Aug 26, 2007
    Messages:
    29,475
    Likes Received:
    16,957
    Location:
    YO11 2BD
    Now i see what you want......

    Convert the stereo output to mono in both earpieces at the same time, not to have stereo at the earpieces.
    is there any mode to have mono from your source....some devices can switch between stereo and mono in a menu or settings.

    But why would you want a burger when you can have steak ?
     
  6. magicsurfbus

    magicsurfbus Funster

    Joined:
    Oct 11, 2010
    Messages:
    3,507
    Likes Received:
    8,261
    Location:
    NW England
    I'm just going on what the eBay listing and the Kenable (manufacturer) website both say - that it's not suitable for stereo output to mono input.

    I'm guessing there may be some sort of resistance (for want of a better word, maybe impedence?) issue with the headphone speakers which is why the plugs are so huge in the first place, but I don't understand electronics, hence my query.
     
  7. magicsurfbus

    magicsurfbus Funster

    Joined:
    Oct 11, 2010
    Messages:
    3,507
    Likes Received:
    8,261
    Location:
    NW England
    I'm assuming in a simplistic way that each headphone will behave like a stereo speaker, Left speaker signal to one headphone, Right speaker signal to the other.

    It's just that big bulky headsets are back in among certain groups of youngsters at present and they attract a good price if they'll work on a modern stereo device. I paid peanuts for them so there's a potential profit to be made.
     
  8. Lenny HB

    Lenny HB Funster

    Joined:
    Oct 18, 2007
    Messages:
    5,254
    Likes Received:
    5,054
    Location:
    West Sussex
    The adaptor should work OK the tip of one of the ¼" sockets should go to the ring of the 3.5mm jack and the other one to the tip of the 3.5mm.

    As the headphones old you need to check the impedance of them they could well be low impedance (8 ohm), which will either just not work or overload your output.
    Modern headphones are high impedance 1k ohm+ so that they can work of pre- amp (line level) outputs.
     
  9. Gellyneck

    Gellyneck Funster Life Member

    Joined:
    Jun 5, 2014
    Messages:
    1,445
    Likes Received:
    2,049
    Location:
    Scotland
    The description on Amazon does say "Please note this device is not designed to convert a 3.5mm out to two 6.35mm Mono cables.".

    OK, a bit Heath Robinish but you could do this (http://www.cabling4less.co.uk/produ..._plug_-_2_phono_(left_+_right)_sockets_cable/) to this (http://www.amazon.co.uk/Indigo-Bana..._sbs_ce_2?ie=UTF8&refRID=0Z3MCG9Q6Z7V7MA8D4DM) to your headphones?
    First bit splits the stereo male 3.5mm jack into left and right RCA female sockets. The second bit converts each RCA female socket (left and right channels) into female 6.35mm left channel and right channels sockets. Plug your headphone leads into these to get stereo output.

    However, there must be an easier way like making up your own lead with a stereo 3.5mm male into individual left (ring and sleeve) and right (tip and sleeve) channel 6.35mm sockets?
     
  10. pappajohn

    pappajohn Funster Life Member

    Joined:
    Aug 26, 2007
    Messages:
    29,475
    Likes Received:
    16,957
    Location:
    YO11 2BD
    Ok, but i dont see the purpose of the adaptor then, unless each 6.5mm is a seperate stereo socket which would allow TWO seperate sets 6.5mm headphones to be used simultaniously in stereo mode.

    If so there must be a version somewhere to convert 3.5mm stereo to left and right 6.5mm mono phones giving left and right tracks to repective phones.
     
  11. pappajohn

    pappajohn Funster Life Member

    Joined:
    Aug 26, 2007
    Messages:
    29,475
    Likes Received:
    16,957
    Location:
    YO11 2BD
    >THIS< is what you want......

    From the description info.....

    It is common for splitting a 3.5mm stereo audio channel into left-right RCA configuration.
     
  12. pappajohn

    pappajohn Funster Life Member

    Joined:
    Aug 26, 2007
    Messages:
    29,475
    Likes Received:
    16,957
    Location:
    YO11 2BD
  13. magicsurfbus

    magicsurfbus Funster

    Joined:
    Oct 11, 2010
    Messages:
    3,507
    Likes Received:
    8,261
    Location:
    NW England
    A closer check reveals they're Telephonics TDH-39P noise-reducing earphones which are apparently aircrew standard, so it'd be nice to get them going, if they still work. They might even get me a few pennies in their own right, regardless of 3.5mm jack plug compatibility.

    I've checked with a multimeter at both earcup connections and I'm getting 8.5 - 9.0 Ohms, so that's not good news for everyday stereo, right?
     
  14. Gellyneck

    Gellyneck Funster Life Member

    Joined:
    Jun 5, 2014
    Messages:
    1,445
    Likes Received:
    2,049
    Location:
    Scotland
    That's what I thought but .......!
     
  15. Lenny HB

    Lenny HB Funster

    Joined:
    Oct 18, 2007
    Messages:
    5,254
    Likes Received:
    5,054
    Location:
    West Sussex
    In that case it has probably has a couple of 10k resistors inside to form a passive mixer.

    There is one here that may do the job the F376 may be worth messaging them to check.

    As I said earlier check the impedance of the headphones first otherwise you will be wasting your time.
     
    Last edited: Feb 19, 2015
  16. pappajohn

    pappajohn Funster Life Member

    Joined:
    Aug 26, 2007
    Messages:
    29,475
    Likes Received:
    16,957
    Location:
    YO11 2BD
    But a snot nose yoof wouldnt have a clue what yer on about.
     
Loading...

Share This Page