ATTN: FV24 owners: How to wire a microphone

Alives · 08-24-2002, 02:03 PM

there is a jumper next to the PCI slot for the microphone and speaker out. its pictured here which is also in the attatchment at the bottom of the page.
<img src="http://www.mp3car.com/vbulletin/attachment.php?s=&postid=68025"</img>

this next piece explains mic_in and mic_vcc and GND and how they work. its taken from http://www.epanorama.net/circuits/mi..._powering.html

Quote:

<h4>Sound Blaster way</h4>
Sound Blaster soundcards (SB16,AWE32,SB32,AWE64) from
<a href="http://www.creaf.com/">Creative Labs</a> use 3.5 mm stereo jack for the
electret microphones. The micrphone connector uses he following wiring pinout:

<pre> / \
| | Audio signal
\ /
+===+
| | Bias voltage for microphone (+5V through 2.2 kohm resistor)
|===|
| |
| | Ground
| |
+=======+
| |
</pre>

<a href="http://www.creaf.com/">Creative Labs</a> has given the following
specs for the Sound Blaster microphone input in their web site: 
<pre> Input Type: Unbalanced Low Impedance
Input Sensitivity: Approx. -20dBV (100mV or 0.1Volt)
Input Impedance: 600 to 1500. (Ohms)
Input Connector: 3.5mm Miniplug (Stereo Jack)
Input Wiring: Audio on Tip, Ground on Sleeve, 5Volts DC Bias on Ring
</pre>

<img alt="Microphone connector wiring" src="http://www.epanorama.net/circuits/mic35.gif" width="326" height="99">

The picture blow shows an approximate schematic of Sound Blaster Microphone
input circuitry. It shows my quess on the electronics inside the soundcard and
one typical wiring for a typical Sound Blaster microphone. 

<img alt="Sound Blaster Microphone Input" src="http://www.epanorama.net/circuits/sb_micinput.gif" width="365" height="171">

cproaudio · 08-25-2002, 01:33 AM

The way I did mine is I cut up a junk plug and plug in the SV24 case headphone and then use a meter to test what wire goes to the pin number. The Mic and headphone use the same ground. I noticed the front panel headphone out sounds way better than the rear speaker out. The rear sounded like it's out of phase. For those of you who have the FV24 or FV25 boards out there, use the internal audio out pins instead of the rear panel audio out jacks.

bosstone74 · 12-09-2002, 10:38 PM

I know this is an old post...
but I need a mic.. I have a FV-25 and man, this mambo jambo, with the audio stuff really through me for a loop...di you think you could shed some light on this?
I found the pins...I have the diagram of which pins do what...but I need to figure out how to make a female plug to go to those pins...

bosstone74 · 03-25-2006, 03:48 PM

I just cut the ends off and solder the left and right (red and white) to the appropriate side of the stereo female plug from radio shack and soldered the ground (black) as well...