EXACT 3.5mm stock audio output minijack level ? Mac Pro (8core)

Discussion in 'Mac Pro' started by DULLAH, Oct 20, 2008.

  1. DULLAH macrumors newbie

    Oct 20, 2008
    Greetings to all.

    I have a question regarding the stock audio output on the newer 8-core Mac Pros.
    The 1/8"(3.5mm) stereo "Line Level" output minijack.

    The manual lists a max output level of +6.3dBu, or 1.6Vrms, but does not list which standard the jack conforms to.

    There are 2 common standards when "Line Level" is referred to:

    #1. -10dBV (common amongst consumer products: CD players, etc)

    #2. +4dBu (common amongst professional keyboards and MIDI modules)

    I have had no luck searching various Mac forums, nor googling...

    Does anyone know which standard the "Line Level" output jacks of the Mac Pro conform to ?
    Thanks for any responses.:)
  2. inigel macrumors regular

    Mar 14, 2008
    No where
    I found this in the Jan 08 Mac Pro users guide:

    Analog audio out using the headphone jack (typical values)
    Based on a typical situation with playback of 1 kHz, -3dBFS 24-bit sine wave, 44.1 kHz output sample rate into 150 ohms unless otherwise specified below.
    • Output voltage: 1.4 volts (root mean square) (Vrms) (+5.1 dBu)
    • Output impedance: 24 ohms
    • Output power: 90 milliwatts (mW)
    • Signal-to-noise ratio: Greater than 90 dB
    • Total harmonic distortion + noise: Less than -75 dB (.02 percent)
    • Channel separation: Greater than 50 dB

    Can be found on page 92

    Hope this helps you out.
  3. DULLAH thread starter macrumors newbie

    Oct 20, 2008
    Those specs are clearly for the headphone minijack.
    But thanks anyways.:)

    I know (and listed in my 1st post) what the manual listed for the Audio "Line Level" output minijack, but would like to know which "Line Level" standard it uses...




    ??? :confused:
  4. fwhh macrumors regular

    Aug 11, 2004
    Berlin, Germany
    The EXACT level depends on: the impedance of your mixing desk and the type of sound/wave you are playing. Rated +6.3dBu it will be able to drive both standards, as (I think so, a Mac Pro user should confirm this) you can adjust the output gain to your needs.
  5. inigel macrumors regular

    Mar 14, 2008
    No where
    OH SHI-

    Sorry, disregards that. I read it wrong. :eek:

Share This Page