To make a call using a application in my computer (skype) the built-in microphone doesn't work properly. I tried to use ambient noise reduction, without success. I would like to use a external microphone on line in port, wich doesnt provide power to connect device, so I must use self power peripherals. I would like to use a nonpowerd microphone. Do you have any adaptador wich would give power to the line in port and I could plug in a nonpowerd microphone??