Benjamin Ransum said:
Hello,
My new computer case that I used to built my new computer has a front
panel audio device. The wires are all labeled at the connection things
that attach to the motherboard. My motherboard has a wire diagram, but
I'm confused about one thing. On the front panel audio device there
two EAR R and two EAR L connections.
Does anyone know which EAR is out and which EAR is return?
The case is an Ultra Aluminus and the motherboard is an Intel D975XBX.
I called Ultra and they were no help.
My mother board front panel audio header layout:
Port1L (1) (2) GND
Port1R (3) (4) Presence#
Port2R (5) (6) Sense1_Ret
Sense_Send (7) ( ) Key (no pin)
Port2L (9) (10) Sense2_Ret
From Intel's web site I was able to find out that Port1L is Mic, GND
is GND, Port1R is Mic Power, Port2R is EAR R, Port2L is EAR L,
Sense1_Ret is EAR R return, Sense2_Ret is EAR L return.
I hope this stays together as I have typed it out on my computer.
Please tell me which wire on the front panel audio device goes where
on my mother board.
The wires on the front panel audio device are labeled "Mic In" (Red),
"GND" (Black), "Ear L" (Orange), "Ear R" (Green), "Ear R" (Brown),
"Ear L" (Black), "Mic Power" (Yellow).
Hope someone can help.
Sincerely,
Injam
The pin names on your motherboard header, are HDAudio names.
The names on your front panel wiring are AC'97 names. The
two standards aren't exactly the same, so there may be a
resultant lack of functionality.
A document showing both types, is here. The formfactors site
contains Intel documents for various standardization efforts,
like power supplies and the like. See section 2.3.5, Pg 22.
http://www.formfactors.org/developer\specs\A2928604-005.pdf
Port1L and Port1R are for the microphone jack. The bias resistors
are set up for a stereo electret microphone, and I assume a
mono would work as well. Port2 is for headphones. The three
sense pins, are for isolated contact pairs on the microphone and
headphone jacks. Now, they would be missing on an AC'97
computer case, such as yours. In order for an audio codec
to detect that a jack is plugged, the codec would need
an internal impedance sensing function.
There is no need for the loopback of the headphone signals,
because AFAIK, HDaudio uses separate output ports for the green
Lineout on the back of the computer, and for the Port2
headphones. The software is in control of whether those two
outputs are enabled simultaneously or not. If jack sensing
was working properly, for example, the HDaudio driver could
mute the rear speaker output, when it detects that
headphones have been plugged into Port2L/Port2R.
Port1L (1) (2) GND
Port1R (3) (4) Presence#
Port2R (5) (6) Sense1_Ret
Sense_Send (7)
Port2L (9) (10) Sense2_Ret
The Intel BadAxe manual says a Sigmatel 9221 or a 9220 is
the codec. And there is no datasheet available on this page.
http://www.sigmatel.com/products/pcaudio/desktop/stac9220.asp
How the jack sensing works, is shown on page 172 here. This
diagram is not completely consistent with the other Intel
document, as I think the position of the switch and
resistor have to be reversed. In other words, the isolated
contact pair on a jack, are not ground referenced. The
resistors connect to ground.
ftp://download.intel.com/standards/hdaudio/pdf/HDAudio_03.pdf
In that diagram on page 172, since your Sense_Send, Sense1_Ret
and Sense2_Ret do not have wires coming from the front audio,
they will not be connected. The only consequence, is that
the codec won't be able to detect that the plugs are occupied,
using the resistors. The codec will have to periodically
poll the jacks, and attempt to sense their impedance on tip and
ring. It is difficult for me to guess as to whether that is
going to be what happens or not. Either the above wiring will
work, or the audio codec may not know that anything has been
plugged in. You'll have to experiment and see what happens.
On an Asus motherboard, there is a BIOS option to put the
header in a pseudo AC'97 mode or in HDaudio mode. You are
in need of that pseudo AC'97 mode, but maybe the Intel BIOS
doesn't have that.
Anyway, after that excessively long preamble, here is your wiring:
Mic <--------> Port1L (1) (2) GND <------------> GND
Mic_Power <--> Port1R (3) (4) Presence#
Ear_R <------> Port2R (5) (6) Sense1_Ret
Sense_Send (7)
Ear_L <------> Port2L (9) (10) Sense2_Ret
* Second Ear_L and Ear_R are not used.
The formfactor document (the first link) states that
Presence# should be connected to ground through a 1000 ohm
resistor. If no connection is made to the pin, as I show
in the above figure, then the BIOS will not know you have
wired stuff to the front panel. I don't understand why
they don't just let it be connected to ground.
So, try the above connection diagram first. See whether the
BIOS knows or cares about the 2x5 audio header or not.
If the BIOS does care in some way, then you'll need a way
to ground Presence like this. Chances are, connecting
it directly to GND would also work. (Why the docs say to
use a 1000 ohm resistor, boggles the mind. If it is a
logic input, it should be able to go right to GND.)
(4) Presence# -----1000ohm_resistor-----GND
Report back how it works out, for the benefit of any other
BadAxe owners who are thinking about trying it.
Also, since the D3611001 user manual doesn't describe all
the BIOS functions, I'd be curious as to what settings are
available, with respect to that audio header.
Paul