Hi there! Here's my deal: I have a Yamaha P-155 digital piano, and I'd like to record it onto my Macbook Pro, through the use of my Lexicon Lambda USB interface. But I don't want to use MIDI - I want to record the actual sounds from the keyboard. The keyboard has an "aux out" on the back, with R and L/L+R jacks, as well as MIDI terminals and a USB to device connection. How am I supposed to record this correctly? I connected an instrument cable from the L jack on the keyboard to the instrument jack on the Lambda - it recorded everything, but there was noise. When I'm just monitoring with this connection made, there is noise, until I unplug it. Am I not doing something right? Is there a certain cable that I need to plug into both L and R jacks, and a way to get a clear recording? I know I can record something directly onto a flash drive with the USB port, but I'd like to be able to input directly into GarageBand and not have to deal with an extra step. Thank you!