digital noise on iMac
Hi,
last friday the mainboard of my old iMac (2008 Core 2 Duo 2.66 MHz) died. So I got a new iMac (2.7 GHz Core i5) as a replacemant.
The only difference between the old and new situation is the iMac and the Firewire cable (because of the new Firewire 800 port).
My audio interface is a Focusrite Saffire 10 I/O, and my speakers are Yamaha HS50M's.
In the old situation, all was nice and quiet, but I hear a bit of digital noise coming out of the speakers now; it begins when I start Logic, and stops when I quit Logic.
On the headphones, all is nice and quiet, and there's no noise in the recorded audio, either. When I use my old (Firewire) Behringer FCA202 audio interface, I get the same noise through the speakers; and a Behringer UCA202 USB audio interface gives the same noise, too.
Any have an idea what causes this? Can it be electro magnetic interference from the iMac? Or a grounding issue?
As said, it happens with both Firewire and USB audio interfaces. It's not loud, but it's slightly annoying nevertheless.
Thanks for any clues!
Jaap