Hi guys, I used to be able to record from my microphone input from my headphone output, but now when I attempt this I get superposed a strange periodic pulse, I know my microphone input is fine as that works if I use my mic with it and record my voice, I know my headphone out is ok as I can listen to things, so its something to do with the two, but I have no idea what it is? any help would be appreciated thanks guys