Hi Im running logic 9 hrough an M Audio fast track pro with Yamaha HS50M monitors. Sometimes when I launch Logic I get an audible high frequency hum from the speakers, it sounds a bit like picking up an out of tune radio. But I can run itunes or any DVD through the fast track and speakers with no hum, its only through logic and starts at exactly the same time each time, halfway through the launch of the program. I don't need to have a project open or be playing any tunes. Any ideas? its not the worst sound in the world but i could live without it

Hi Hamish, I would try two things. Check the grounding in the room you are in. Also, if possible borrow another brand interface and test it in your setup. What kind of monitor speakers are you using? Cheers Rounik

Thnaks Rounik! I'm using Yamaha HS 50 M active monitors. I've also thought it might be the cabling, at the moment its unbalanced 1/4" TRS jacks but I can change it to XLR, do you think this would make a difference? How do I check for grounding? none of the equipment I'm using appears to have a ground wire or anything like that. At some point I'll be moving up from the fasttrack pro so hopefully I'll get the chance to try a new interface soon. Thanks for the tips! :)

Hi Hamish, Here's a link on Ground Loops: [url]http://www.epanorama.net/documents/groundloop/[/url] I'm sure that'll help much more than I can! I'd definitely suggest trying out different cables to check the effect... also perhaps try shielded cables? Hope this helps. :) Rounik