Echos??? Make sure that any microphone device on your computer is turned off while you're recording, just in case. Check for that in volume settings & audio settings.
I thought it was the built in microphone, but it turns off when something is in the jack. My computer is just shitty at recording I guess. And I turn down the gameboy and turn it up in audacity. I do this just to avoid static at really loud or congested areas.