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DULLAH

macrumors newbie
Original poster
Oct 20, 2008
2
0
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.:)
 
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
http://manuals.info.apple.com/en_US/Mac_Pro_Early_2008.pdf

Hope this helps you out.
 
^No.
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...

+4dBu

...or...

-10dBV


??? :confused:
 
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.
 
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