Front Panel Audio - Help

  • Thread starter Thread starter Victor Papa
  • Start date Start date
V

Victor Papa

Hi all,

I've just aquired a front panel that has a Card Reader, USB, Firewire and
Audio. I've got the Card Reader, USB and Firewire working great but I can't
work out the audio connections. My motherboard is an MSI 848p Neo-V (AC97)
with the following JAUD1 front panel connection pins:

1 AUD_MIC
2 AUD_GND
3 AUD_MIC_BIAS
4 AUD_VCC
5 AUD_FPOUT_R
6 AUD_RET_R
7 HP_ON
8 KEY
9 AUD_FPOUT_L
10 AUD_RET_L

The front panel audio lead has connectors that are as marked follows:

1 MIC-R
2 MIC-L
3 FRONT-R
4 FRONT-L
5 REAR-R
6 REAR-L
7 GND
8 BASS
9 CENTER

After connecting logically, I have no sound from the back panel at all but
can get sound if I plug headphones into the Front Out jack on the panel. I
was hoping to get sound from the back for normal speakers but then get sound
from headphones plugged into the front panel. AFAIK, plugging in headphones
should disable the rear panel sound. Also, it would appear that the 'Mic In'
on the front panel doesn't work either, or if it does, it's extremely quiet.
I've looked in the motherboard manual but other than saying that if pins 5+6
and 9+10 are jumpered, the signal is directed towards the back panel, it
basically just lists the pins and their labels. It would appear that to
connect the FP lead, the jumpers on 5+6 and 9+10 have to be removed.

Any guidance as to which connector goes onto which pin to get the desired
result would be very much appreciated.

Thanks in advance,

Victor
 
In alt.comp.hardware.pc-homebuilt "Victor Papa"
Hi all,

I've just aquired a front panel that has a Card Reader, USB, Firewire and
Audio. I've got the Card Reader, USB and Firewire working great but I can't
work out the audio connections. My motherboard is an MSI 848p Neo-V (AC97)
with the following JAUD1 front panel connection pins:

1 AUD_MIC
2 AUD_GND
3 AUD_MIC_BIAS
4 AUD_VCC
5 AUD_FPOUT_R
6 AUD_RET_R
7 HP_ON
8 KEY
9 AUD_FPOUT_L
10 AUD_RET_L
Click to expand...
As I recall, on many motherboards you have to jumper the "out" to the
"ret" or something like that. I think it's intended for front-panel
connectors that have disconnecting-jacks; so if you plug in the
front-panel, the rear connecter automatically gets disconnected.

They usually come with a set of jumpers or a jumper-plug for use if you
don't have the proper front-panel.
 
IIRC, on most mother boards, if you hook up the front panel
speaker/mic lead, that will negate the jack at the back of the
computer on the I/O panel. Kinda like plugging headphones into your
stereo, they cut the circuit to your speakers.


--

The Seabat

NewsProxy: Allowing me to blissfully avoid the havoc
caused by Google goobers!
 
Victor said:
Hi all,

I've just aquired a front panel that has a Card Reader, USB, Firewire
and Audio. I've got the Card Reader, USB and Firewire working great but
I can't work out the audio connections. My motherboard is an MSI 848p
Neo-V (AC97) with the following JAUD1 front panel connection pins:

1 AUD_MIC
2 AUD_GND
3 AUD_MIC_BIAS
4 AUD_VCC
5 AUD_FPOUT_R
6 AUD_RET_R
7 HP_ON
8 KEY
9 AUD_FPOUT_L
10 AUD_RET_L

The front panel audio lead has connectors that are as marked follows:

1 MIC-R
2 MIC-L
3 FRONT-R
4 FRONT-L
5 REAR-R
6 REAR-L
7 GND
8 BASS
9 CENTER

After connecting logically, I have no sound from the back panel at all
but can get sound if I plug headphones into the Front Out jack on the
panel. I was hoping to get sound from the back for normal speakers but
then get sound from headphones plugged into the front panel. AFAIK,
plugging in headphones should disable the rear panel sound. Also, it
would appear that the 'Mic In' on the front panel doesn't work either,
or if it does, it's extremely quiet. I've looked in the motherboard
manual but other than saying that if pins 5+6 and 9+10 are jumpered, the
signal is directed towards the back panel, it basically just lists the
pins and their labels. It would appear that to connect the FP lead, the
jumpers on 5+6 and 9+10 have to be removed.

Any guidance as to which connector goes onto which pin to get the
desired result would be very much appreciated.

Thanks in advance,

Victor
Click to expand...

This is the fault of your computer case wiring. The nine pins listed
are not an "Intel-compatible" configuration.

I typed up some notes on this not long ago:

http://groups.google.ca/group/alt.c....elitegroup/msg/313e3a1efb1dcbfc?dmode=source

Your case wiring is yet another variation. It looks like it is intended
for a 5.1 front panel setup, where as the motherboard is set up for
stereo (headphones). So the computer case 5.1 wiring is not likely to
find anything to plug into, inside the computer.

That means your usable wires, of the nine you list, are these five. The
other four can be left dangling inside the computer case. Only the "front"
jack will work for the headphones. Plugging in headphones will not operate
a mute function. With only five wires on the computer csae, you are
missing the return wires. Which is why the green connector on the back of the
computer no longer works.

1 MIC-R
2 MIC-L
3 FRONT-R
4 FRONT-L
7 GND

When connected, they'd look something like this:

MIC-L X X GND
MIC-R X X
Front-R X X (return wires are missing!)
X
Front-L X X (return wires are missing!)

MIC-L should correspond to the "Tip" of the 1/8" microphone plug.
It carries the actual monophonic microphone signal.

MIC-R is the microphone bias, a form of power supply. Usually,
it is a 5V supply, with a 2K ohm series resistance. If you plug
in an "electret" microphone, that kind of microphone uses the
small amount of available power, to amplify the signal. The
electret will give a decent, high level signal. For other
microphone types, you may need to actuate the "Mic boost" checkbox
in the audio interface. There is the odd bit of motherboard
audio, where there is no boost, but for many of them, it
is merely a well hidden setting.

MIC-R corresponds to the "Ring" contact of the 1/8" microphone plug.

GND goes to the "Sleeve" contact of both the headphone and the
microphone jacks.

If you wish the headphone ("Front") jack, and the speakers to
work at the same time, you'll need to wire across, like there were
jumpers in place. In other words, not only do you have to connect
Front-R and Front-L as shown, you also need to jumper as shown by
the <-> in the picture. Some very fine wire wrapped around the
pins is one way to do it. Soldering to the back of the motherboard,
and bridging where the jumpers normally go, is another way to
permanently leave the green rear speaker jack enabled.

MIC-L X X GND
MIC-R X X
Front-R X<->X (return wires are missing!)
X
Front-L X<->X (return wires are missing!)

And if you remove the computer case wiring assembly, and put the
two jumpers back in place, that also will restore the operation
of the green rear speaker jack.

Paul
 
Paul,

Thanks for that - I'll have a go at wiring across the pins soon and see what
I can come up with.

Victor
 
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