Creative Sound Blaster Pro 2
The Sound Blaster Pro 2 was a revision to the original SB Pro, replacing the dual OPL2 chips with a single OPL3. The card is technically only an 8-bit one - the extra connectors that fit into the 16-bit slot are only used for selecting IRQ 10 and/or DMA 0.
JP2: Audio extension connector
These pins provide speaker output and microphone input for interfacing with other cards. They are located just behind the mic/line jacks.
|1||MICR||Mic input, right channel. Input from 0.004 to 0.7 V rms.|
|2||MICGEN||Mic input, ground.|
|3||MICL||Mic input, left channel. Input from 0.004 to 0.7 V rms.|
|4||SPKGND||Speaker output, ground.|
|5||SPKR||Speaker output, right channel. Maximum output voltage is 3 V rms at 4 ohms.|
|6||SPKL||Speaker output, left channel. Maximum output voltage is 3 V rms at 4 ohms.|
|7||SPKRL||Speaker output return, left channel.|
|8||SPKRR||Speaker output return, right channel.|
JP3: PC Speaker output connector
These pins provide an output that can be connected to the internal PC speaker, to allow all audio from the card to be heard through the internal speaker. It is currently unknown whether this output is muted when the line-out jack is in use. The jumper is located next to JP2.
|1||SPKR||Speaker output, right channel. Maximum output voltage is 3 V rms at 4 ohms.|
|2||SPKRR||Speaker output return, right channel.|
- Sound Blaster Pro - Getting Started manual, section D-2.