BUMP BUMP

Surely someone has pondered this.

I searched 'mb-pro pinout' and came up with this:

There is a MB_PRO connector on the Live Value, and it is 2x5 with 9 pins. There is a post in Google with the pinout, but the sig […]
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There is a MB_PRO connector on the Live Value, and it is 2x5 with
9 pins. There is a post in Google with the pinout, but the signals
don't look interesting, in terms of getting a case front panel audio
connection out of them. The Google post says this is the pinout,
without giving a reference as to where the info came from:

Pin Description
1 AGND
2 KEY
3 LINE_IN
4 AGND
5 LINE-OUT-L
6 AGND
7 LINE-OUT-R
8 MONO-IN
9 AGND
10 MIC-IN

Alright now were getting somewhere. One other thing I had noticed is that there are three wires coming from the microphone jack, and there is only two connections on the card. So the card is missing the connector for the "Mic bias". From what I read this mean that I can only use dynamic, not electric. Hopefully it will work with my headset. I'm also interested to know if plugin in the mic will silence the back output.

An electret mic will really not work without bias voltage, it will simply produce no signal.

You can faithfully recreate the mic bias pin. Pull +5V and GND from a floppy power connector. Then connect up like this:

That's exactly the same thing SoundBlaster does internally. Most other cards feed the bias right through the tip, which would make them useless with dynamic mics, but SoundBlaster doesn't do that.

L is optional but if you have a tiny choke at hand, it might help. The value of C is also not to be taken too exactly, and i suppose you can try letting it out entirely, but you might experience a lot of noise in the mic.

I'm not entirely sure, but it seems that SB live (at least my 4670) disconnects MB_PRO inputs when back panel inputs are connected. Outputs however are connected both ways.

As this seems to be true, one could solder together the switch pins of the back pane mic connector such, that the bias is fed to MB_PRO mic tip, but as soon as you plug a mic into the back, that mic will not receive the bias, so you can keep an electret headset at the front, and occasionally plug in a dynamic or electret in the back.