Two MV1C questions

I have an MV1C mobo I just bought and I need to test it to make sure it works. I don't have a supergun, but I do have a 4 slot dedicated cab. Will it damage the MV1C to plug the connecter from the cab straight onto it? I know the MV1C doesn't support stereo, so I don't know if it would be damaged in the 4 slot cab. Second, what is the 8 pin connecter next to the volume control for. The wiring diagram in the manual did not say.

a) no , it'll be fine
b) can't remember, but you don't need to use it, credit LED's or something external

I forgot to thank you for the info