Okay here is my problem, I have a Roland DP-900, and I hook it up to my MacBook via a external sound-card made by Behringer (UCA202). When I use iMovieHD to record audio and video, after about 20 seconds the recorded sound gets bombarded with static noise. Does anyone know why this might be occurring, and how I might stop it?

I would go through the normal troubleshooting steps. Keep changing 1 thing I would the signal chain until you figure out which causes the issue to stop.

Does the static still occur if you hook the audio output directly into the MacBook?

I can't hook the output into my MacBook because it has no stereo input jacks. The sound card slots into my USB drive.

When I use my MacBook's built-in mic, I have no problems with the audio (apart from its very low sound quality, hence the soundcard).

Talk to a friend and hook the sound card up to a different computer? Different cable? Different sound card I. Your mac book if someone else has one? You've got to rule things out.

Yeah, I know, but I figured I would try and see if anyone had any ideas here first, before I go systematically ruling things that are not immediately obvious out.

I can't hook the output into my MacBook because it has no stereo input jacks.

You don't have to have a separate Left and Right output or input jacks or plugs to have stereo, the computer could still use a single jack with three segments (L, G, and Ground) ... or do you know for a fact that the MacBook only accepts a mono input?

Think of a headphone jack.

http://answers.yahoo.com/question/index?qid=20090902153312AAxtZVA

How can you get stereo if the computer has no stereo input jack????

My five year old PC has a stereo input so I can well imagine that the Mac does as well. If in doubt simply open up the computer and see the number of wires soldered or connected to the input jack. I'll bet it's stereo.

The earlier poster mentioned a Mac Book. Not sure about those.
But ...

Desktop? Sure, standard stereo line inputs.
Laptop? Likely to have a mono mic input and no line inputs.

Which MacBook is it? Is it a MacBook pro? If it is the 13 inch, the single mini-jack is stereo and it can be converted to an output or an input by way of System Preferences.

Thank you, I never knew this. I always just assumed the headphone jack was only an output. I will give it a try with my piano.

It worked brilliantly. Thank You.

So glad you solved it - play and record away! Let's see/hear some now that you are set-up!

Glen