Re: OT: ? Front panel audio - guru required !
- From: Paul <nospam@xxxxxxxxxx>
- Date: Mon, 21 Jan 2008 18:05:09 -0500
Oh.... those were the days when I could connect anything to anything !
Can anyone tell me how to connect motherboard Front Panel Audio Header (9-pin HD_AUDIO1), to an old (AC'97
?), case Front Panel Audio panel.
The motherboard is an "all in one" Asrock ALIVEN56G-VSTA/M/ASR with 6 x
3.5mm jacks on the ATX block of connectors.
The case front block of plug-holes only has 2 x 3.5mm jacks for Mic. and
Headphones, ...(and 2xUSB and a 1394a firewire port)
Obviously I can't, (and don't want to), make use of "High Definition" Audio, (there's not enough
plug holes on the case front), but, I should be able to connect
microphone, and stereo headphone case front fly lead tails ?.
...as usual - only part of the required information is in the motherboard (Asrock) "manual" :-
1. High definition Audio supports Jack Sensing, but the panel wire on the
chassis must support HDA to function correctly. Please follow the
instruction in our manual and chassis manual to instlal your system.
(that's the bit I don't want and can't use of course).
2. If you use AC'97 audio panel, please install it to the front panel audio
header as below:
A. Connect Mic_IN (MIC) to MIC2_L.
B. Connect Audio_R (RIN) to OUT2_R and Audio_L (LIN) to OUT2_L.
C. Connect Ground (GND) to Ground (GND).
D. MIC_RET and OUT_RET are for HD audio panel only. You don't need to
connect them for AC'97 audio panel.
E. Enter BIOS Setup Uitility. Enter Advanced Settings, and then select
chipset Configuration. Set the Front Panel Control option from [Auto] to
F. Enter Windows system. Click the icon on the lower right handtaskbar to
enter Realtek HD Audio Manager. Click "Audio I/O", select "Connector
Settings, choose "Disable front panel jack detection", and save the change
by clicking "OK".
Now for the fun part:
Motherboard - Front Panel Audio Header (9-pin HD_AUDIO1)
246x10 (x position blank / "key", or no pin if you like)
13579 (or should that be a 8 where the 9 is, ..and a 9 where I've put the 10 ? :-( ...I'll leave it as it is !
Pin 1. MIC2_L
Pin 2. GND
Pin 3. MIC2_R
Pin 4. PRESENCE #
Pin 5. OUT2_R
Pin 6. MIC2_RET
Pin 7. J_SENSE
Pin 8. no pin
Pin 9. OUT2_L
Pin 10. OUT_RET
AC'97 from case front panel tails:-
...anyhooo after riduculous amounts of time scouring the web, I propose :-
tail MIC-IN connected to pin 1. MIC2_L
tail GND connected to pin 2. GND
tail LINE-IN-R connected to pin 5. OUT2_R
tail LINE-IN-L ocnnected to pin 9. OUT2_L
...so does MIC-VCC (bias) need to be connected anywhere ?
...and LINE-OUT-L and LINE-OUT-R seem to have nowhere to go.
Any thoughts MOS appreciated.
Looking at the motherboard manual:
there are five pins of interest.
The ground is shared by the two front jacks. Each jack has
three contacts. So that is enough wires to do the job.
The rest of the labeled pins are HDaudio specific and not
needed for an AC97 computer case wiring.
Now, I'll use your computer case signal list, and put the
FP_AUDIO signal name to the right of it.
> Gnd GND
> MIC-VCC MIC2_R <------- bias for electret microphones
> MIC-IN MIC2_L <------- audio signal from microphone
> LINE-OUT-L OUT_L headphone signal from AC97 chip to jack
> LINE-OUT-R OUT_R headphone signal from AC97 chip to jack
> LINE-IN-L (no connection - return not used on HDaudio)
> LINE-IN-R (no connection - return not used on HDaudio)
The problem with the names your computer case is using, is I
cannot tell which of "out" or "in" is the "return" signal. So the
above table is tentative. If you aren't getting the headphones
to work, try moving the OUT_L and OUT_R down two positions in
the above table. One pair or the other, is the actual output,
so one of the pairs should work, and the other give nothing.
The BIOS setting is important, because it prepares the driver
to not expect switch closure jack sensing. Impedance (load)
sensing will have to be used instead. I don't know exactly how
that works - I have some theories, but no tech articles to back
up the theories.