How to connect front audio ports to mobo

  • Thread starter Thread starter *Vanguard*
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*Vanguard*

I got an Abit NF7-S which has a 14-pin header for front panel audio
connectors. In this header there are 2 pins for the left channel and 2
for the right channel. Across the left-left pins is a jumper and the
right-right pins are also jumpered. So there are:

left o-o left
right o-o right

where o-o is the jumper across the 2 pins. I got a case that had audio
connectors on the front figuring to hook them up to this header. Not so
easy, though. The audio connectors on the front of the case go to a
shielded 2-wire cable with a mini plug on the end (the type and size you
plug into your portable radio). This means there are only 3 conductors:
left, right, and ground/shield. The pins in the header aren't labelled:

left o-o ground
right o-o ground

If that were indeed the actually signal connections in the mobo header
then I could probably rig up a converter from the 1/8" mini stereo plug
to go to the header pins (i.e., wire up a female stereo plug where the
shield went to both of whichever are the unmarked ground pins in the
header and the 2 signal lines to which were the left and right signal
pin in the header).

I believe headphone jacks work by being shorted when no plug is
installed. With no headphone plug inserted, the jack is shorted and so
the header pins would also be shorted. When you insert the headphone
jack, the circuit opens and has to pass to and through the headphone
speakers. Okay, but still there are only 3 wires in the headphone jack:
left, right, and ground/shield. Yet there are 2 pairs of pins for a
total of 4 connections.

The 14-pin header is supposed to be used for the Abit Media XP Pro kit.
It has 2 USB ports but I already have that in the case's front panel.
It has 1 fireware port but I have 2 in the rear bracket and which also
adds another 2 USB ports at the rear. It adds an S/PDIF input but I
don't need it, just like I don't need the memory stick reader slots.
There really isn't a reason to waste a 5-1/4" drive bay for their media
kit since all I want is to hookup the audio ports in the case front
panel to the header on the mobo, but I'm not sure it can be done.

The case's front panel also provides a mic port. Peculiarly they also
attached a stereo mini plug to that port although the left and right are
shorted together (since the mic input is mono, anyway, especially since
there is only one "mic" pin in the 14-pin mobo header so the other
connection is to ground/shield).

So for the audio ports in the case, is that I:

- Remove the jumper from the left-left set of pins in the 14-pin mobo
header.
- Connect the left-channel conductor from the stereo mini plug from the
case panel audio port to, say, the leftside "left" marked pin in the
header.
- Remove the jumper from the right-right set of pins in the 14-pin mobo
header.
- Connect the right-channel conductor from the stereo mini plug from the
case panel audio port to, say, the leftside "right" marked pin in the
header.
- Run the ground/shield conductor from the stereo mini plug from the
case panel audio port to both the rightside "left" and "right" marked
pins in the header.

And for the mic port in the case, I would:

- The left- and right-channel conductors in the stereo mini plug are
shorted together (for mono mic input). So run either to the "mic"
marked pin in the header.
- Run the ground/shield conductor from the stereo mini plug from the
case panel mic port to the "gnd" marked pin that pairs up with the "mic"
marked pin in the header.

Or maybe it just can't be done and I'll have to forego the front panel
ports for headphone and mic. The cables are long enough to pass out
through a cutout in the backside. So I could run the mic cable to the
mic input of the sound card. But I can't run the headphone cable to the
line-out connector on the sound card else I lose the connection to the
speakers, and using a Y-adapter to connect both speakers and headphone
to the line-out jack won't get the speakers to cut out when the
headphone is plugged in.
 
What you need to do is read page 3-15 of the manual
which has the pin connections for the FPI 02 header,
which is where your connections are. The left and
right outputs are on 2 pins each.

The mic goes to 1 hot, 2 gnd.
Left to 9 and or 10
Right to 5 and/or 6
Audio low to pin 11 ground.
 
What you need to do is read page 3-15 of the manual
which has the pin connections for the FPI 02 header,
which is where your connections are. The left and
right outputs are on 2 pins each.

The mic goes to 1 hot, 2 gnd.
Left to 9 and or 10
Right to 5 and/or 6
Audio low to pin 11 ground.
Click to expand...

He seems to have that part figured out, is evident enough from the
manual but is jumping to conclusions about the audio jacks... a stereo
jack with 3 pins doesn't switch between NO and NC, which is what he
needs, a NC (normally closed) jack.


Dave
 
in news:[email protected]:
What you need to do is read page 3-15 of the manual
which has the pin connections for the FPI 02 header,
which is where your connections are. The left and
right outputs are on 2 pins each.

The mic goes to 1 hot, 2 gnd.
Left to 9 and or 10
Right to 5 and/or 6
Audio low to pin 11 ground.
Click to expand...

As Kony pointed out, I pretty much figured out the header pins. There
are 4 pins: leftside "left", rightside "left", leftside "right", and
rightside "right". That is, the header has 2 pins for "left" and 2 pins
for "right". Yet with the audio jack, cable, and mini-plug on the end
of the cable, there are only 3 conductors: tip, middle, rear
(ground/shield).

The 2 "left" pins on the header are shorted by a jumper. Same for the 2
"right" pins. So how do I wire 3 conductors from the audio cable
mini-plug to 4 pins on the mobo header? Even if the audio jack on the
front panel were a NC (normally closed) switch, which it is not,
attaching one conductor to the left, another to the right, and the
ground/shield to the ground-side pins for left and right would end up
shorting them all together, and I doubt left and right are supposed to
get shorted together.

I've done some ohmic testing and found none of the 2 left and 2 right
pins on the mobo header are connected to the ground pin in that same
header. So it's not that there are 3 pins, one for left, one for right,
and the other 2 are just ground pins. There are 4 pins and none of
which are ground. So it seems that I'd need a headphone jack that had 4
conductors (or maybe 5 where one is the ground/shield) where the 2
conductors for the left channel must be shorted and the 2 conductors for
the right channel are shorted when no headphones are plugged into the
jack which then open to connect to the headphones, but headphones also
only have 3 conductors. Do headphone jacks have 4 conductors, 2 for
left (tip) and 2 for right (collar), plus maybe a 5th for the
ground/shield?

Plus the audio jack isn't a normal headphone jack (although I might be
able to replace it with one) but instead just passes the connections
straight through. I suspect that I am supposed to push it into the
line-out (front speaker) jack on the sound card which merely moves that
jack physically from the rear of the case to the front. But they I'd
have to use a Y adapter to hook up the speakers, the speakers wouldn't
cut out when I plug in the headphones into the front jack, and it would
end up with 2 sets of speakers on the line-out jack (the speakers and
the headphone speakers).

I was hoping someone that used the mobo front-panel header, especially
if for an Abit NF7-S, had figured out how to hook them up to an audio
jack on the case's front panel. Or to find out if Abit was stupid in
providing effectively an audio extension cord instead of a real
headphone jack. I can run the mic cable out through the back to the mic
jack on the sound card since the purpose would be to simply make it
easier to plug and unplug the mic from the front. I really don't want
to just move the [front] speaker connection to front but really wanted a
headphone jack capability. It looks like Abit designed this front panel
header to be used ONLY with their Abit Media XP Pro kit that fits in and
consumes a 5-1/4" drive bay. So I might get forced into getting it. It
was pricey at newegg.com for $63 but a link at Abit took me to
excaliberpc.com where it is $25. Guess I'll have to can the idea of
hooking up the mobo headers for audio to the audio jack to the case
front.

It is misleading for Abit to claim to provide a front-panel header for
audio when all they really provided was a specialized header just for
their own product. It should not have been called a front panel header
but instead called an Abit Media XP Pro Kit header. For other users
that have cases with front panel audio jacks, do you have wires with
2-pin headers to connect to mobo pins or do you also have an audio
cable?
 
As I said, 9/10 are the same, both hot.
As are 5/6. Put the left wire(usually white) on 9/10 and the right
wire(usually red) on 5/6 and ground(shield) on 11. You're going to
use 5
header pins in effect. Use normal unswitched jacks for
line level outputs. You can use a shorting jack for the mic in
to ground the input when it's unused.

*Vanguard* said:
in news:[email protected]:
What you need to do is read page 3-15 of the manual
which has the pin connections for the FPI 02 header,
which is where your connections are. The left and
right outputs are on 2 pins each.

The mic goes to 1 hot, 2 gnd.
Left to 9 and or 10
Right to 5 and/or 6
Audio low to pin 11 ground.
Click to expand...

As Kony pointed out, I pretty much figured out the header pins. There
are 4 pins: leftside "left", rightside "left", leftside "right", and
rightside "right". That is, the header has 2 pins for "left" and 2 pins
for "right". Yet with the audio jack, cable, and mini-plug on the end
of the cable, there are only 3 conductors: tip, middle, rear
(ground/shield).

The 2 "left" pins on the header are shorted by a jumper. Same for the 2
"right" pins. So how do I wire 3 conductors from the audio cable
mini-plug to 4 pins on the mobo header? Even if the audio jack on the
front panel were a NC (normally closed) switch, which it is not,
attaching one conductor to the left, another to the right, and the
ground/shield to the ground-side pins for left and right would end up
shorting them all together, and I doubt left and right are supposed to
get shorted together.

I've done some ohmic testing and found none of the 2 left and 2 right
pins on the mobo header are connected to the ground pin in that same
header. So it's not that there are 3 pins, one for left, one for right,
and the other 2 are just ground pins. There are 4 pins and none of
which are ground. So it seems that I'd need a headphone jack that had 4
conductors (or maybe 5 where one is the ground/shield) where the 2
conductors for the left channel must be shorted and the 2 conductors for
the right channel are shorted when no headphones are plugged into the
jack which then open to connect to the headphones, but headphones also
only have 3 conductors. Do headphone jacks have 4 conductors, 2 for
left (tip) and 2 for right (collar), plus maybe a 5th for the
ground/shield?

Plus the audio jack isn't a normal headphone jack (although I might be
able to replace it with one) but instead just passes the connections
straight through. I suspect that I am supposed to push it into the
line-out (front speaker) jack on the sound card which merely moves that
jack physically from the rear of the case to the front. But they I'd
have to use a Y adapter to hook up the speakers, the speakers wouldn't
cut out when I plug in the headphones into the front jack, and it would
end up with 2 sets of speakers on the line-out jack (the speakers and
the headphone speakers).

I was hoping someone that used the mobo front-panel header, especially
if for an Abit NF7-S, had figured out how to hook them up to an audio
jack on the case's front panel. Or to find out if Abit was stupid in
providing effectively an audio extension cord instead of a real
headphone jack. I can run the mic cable out through the back to the mic
jack on the sound card since the purpose would be to simply make it
easier to plug and unplug the mic from the front. I really don't want
to just move the [front] speaker connection to front but really wanted a
headphone jack capability. It looks like Abit designed this front panel
header to be used ONLY with their Abit Media XP Pro kit that fits in and
consumes a 5-1/4" drive bay. So I might get forced into getting it. It
was pricey at newegg.com for $63 but a link at Abit took me to
excaliberpc.com where it is $25. Guess I'll have to can the idea of
hooking up the mobo headers for audio to the audio jack to the case
front.

It is misleading for Abit to claim to provide a front-panel header for
audio when all they really provided was a specialized header just for
their own product. It should not have been called a front panel header
but instead called an Abit Media XP Pro Kit header. For other users
that have cases with front panel audio jacks, do you have wires with
2-pin headers to connect to mobo pins or do you also have an audio
cable?
Click to expand...
 
in news:Ca%[email protected]:
As I said, 9/10 are the same, both hot.
As are 5/6. Put the left wire(usually white) on 9/10 and the right
wire(usually red) on 5/6 and ground(shield) on 11. You're going to
use 5
header pins in effect. Use normal unswitched jacks for
line level outputs. You can use a shorting jack for the mic in
to ground the input when it's unused.
Click to expand...

Thanks for the info. I guess I got confused because: (1) There's a
shorting jumper across pins 5 & 6 (left) and a shorting jumper across
pins 9 & 10 (right) so the assumption was that they were not already
shorted; and, (2) Pin 5 is isolated from pin 6 and pin 9 is isolated
from pin 10. Why would they have wasted the money and realestate to
provide 2 amplifiers for a channel and then short them together? I was
testing using a continuity tester that won't exceed the threshold of a
diode (so you can tell if the points are really shorted together or have
some circuitry between) so if pins 5 & 6 are logically the same output
from the amplifier then there must also be some silicon in the way for
some kind of protection or isolation. Guess I'd like to see if Abit
might release any circuit diagram to explain their header pins for
audio. I haven't dealt with Abit before so I don't know how
accomodating they are to end users.

Again, thanks for the info.
 
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