Firewire Noise/Chatter
Ok here goes. need help please!
i am running a Focusrite Saffire LE firewire audio interface with a Macbook Pro late 2009, 3.06 ghz, 4GB RAM. on 10.6.6.
the interface runs on either bus power or mains.
when i run the interface on bus power, i have noise on the output, which is very audible. it sounds like processor 'chatter'.
There is no noise on the inputs, only on the outputs to a mixer, and then on to monitors/headphones.
when the interface is bus powered, and the laptop is on battery power the noise is quite loud, certainly too high to do any serious audio work.
i know it is processor noise as when i do anything on the laptop i can hear the 'noise' doing something - ie the processor working.
when the interface is bus powered and the laptop plugged in, the noise is still present, but at a less volume, but still too loud to do any serious audio work.
when the interface is powered by the mains, and the laptop is plugged in, the 'chatter' is significantly reduced, but is replaced by quite a loud 'hum'. i have been told that this may be a ground loop - and might be cured with a DI box - with ground lift. whether the laptop is plugged in or not does not change the volume of this noise.
surely though i shoudl be able to use the interface on bus power without noise??!?
so what is the problem?
Focusrite say it could be one of many things - i have tried balanced and unbalanced cables - it makes no difference, i have tried changing the power adapter for the interface - no difference. i can hear the chatter through the headphones output on the interface in the above situations, so i know the problem is coming from either the interace, or the laptop.
i have called Apple Support - they dont seem to want to know. they have stated that is probably a Focusrite issue - they have asked that i try turning Airport off, turning my internet router off, or even changing the order of network preferences!! - i dont think they fully understand the issue.
so in short - has anyone had this problem? is it Focusrite, is it the Apple Firewire, as i think, although they say that the firewire is working fine if it makes a connection. i have read there are many problems with Firwire on audio, but there is no solution?
?
can anyone help here?
i am running a Focusrite Saffire LE firewire audio interface with a Macbook Pro late 2009, 3.06 ghz, 4GB RAM. on 10.6.6.
the interface runs on either bus power or mains.
when i run the interface on bus power, i have noise on the output, which is very audible. it sounds like processor 'chatter'.
There is no noise on the inputs, only on the outputs to a mixer, and then on to monitors/headphones.
when the interface is bus powered, and the laptop is on battery power the noise is quite loud, certainly too high to do any serious audio work.
i know it is processor noise as when i do anything on the laptop i can hear the 'noise' doing something - ie the processor working.
when the interface is bus powered and the laptop plugged in, the noise is still present, but at a less volume, but still too loud to do any serious audio work.
when the interface is powered by the mains, and the laptop is plugged in, the 'chatter' is significantly reduced, but is replaced by quite a loud 'hum'. i have been told that this may be a ground loop - and might be cured with a DI box - with ground lift. whether the laptop is plugged in or not does not change the volume of this noise.
surely though i shoudl be able to use the interface on bus power without noise??!?
so what is the problem?
Focusrite say it could be one of many things - i have tried balanced and unbalanced cables - it makes no difference, i have tried changing the power adapter for the interface - no difference. i can hear the chatter through the headphones output on the interface in the above situations, so i know the problem is coming from either the interace, or the laptop.
i have called Apple Support - they dont seem to want to know. they have stated that is probably a Focusrite issue - they have asked that i try turning Airport off, turning my internet router off, or even changing the order of network preferences!! - i dont think they fully understand the issue.
so in short - has anyone had this problem? is it Focusrite, is it the Apple Firewire, as i think, although they say that the firewire is working fine if it makes a connection. i have read there are many problems with Firwire on audio, but there is no solution?
can anyone help here?
Macbook Pro 3.06GHZ, 4GB RAM, Mac OS X (10.6.6)