If you’re using a MOTU Traveler or 828 MkII interface with a Mac running OS 10.4, you may have encountered a series of disconcerting high-pitched whistles. These are caused by audio output from certain applications including the Finder, QuickTime Player, Garage Band, and stand-alone Native Instruments synths. The solution is to reset your interface to its defaults using the following method:

1. If you’re using a Traveler, plug it in to your AC, and then disconnect the FireWire cable at the rear of the interface.

2. Press the Setup knob (Also marked ‘Mix’ on the Traveler) and turn it to the right until you get a ‘Factory Defaults’ screen,
3. Press the Select knob, then the Value knob.
4. Now turn off the interface, plug in the FireWire cable, and then turn the interface back on.

This process should eliminate the whistles, at least for a while. Just watch out for a couple of things as you do this. Turn off your monitors first before turning off the interface in order to avoid any nasty thumps in your speakers. Also, the interface default has phones and main output levels at maximum, so be careful to turn these down before resuming your normal monitoring levels.