Actually I don't have balanced cables, but if that is the issue, would it explain why when Sonar opens the noise gets worse?

I see no reason to use balanced cables what so ever. We are talking about high levels in output.  A line level out only needs that if its really long and then it may not even then. Use balanced cables for low level signals. Mics for example. 

Its not unreasonable to look into the device being defective. I would call them about it.  

John


Its not unreasonable to look into the device being defective. I would call them about it.  

but far more likely is  config / user errors-issues.. although 2 times I have had issues it's down to the makers drivers (yamaha and m-audio)

True Fog. It was just another avenue of investigation. 

What monitors are you using?

How are you hooking everything up?

What sort of mains distribution strategy are you using?

My monitors are M-Audio Studiophile BX8s. Not the greatest but they've never been noisy, I've been using them for a few years now. I'm using quarter inch non balanced cables plugged directly into the interface.

Pardon my ignorance but I'm not sure what you mean by:

What sort of mains distribution strategy are you using?

"What sort of mains distribution strategy are you using?"




Thats British for what power setup do you have coming from the wall socket. 

Another avenue for investigation, do you have any live inputs enabled on your projects that are fed by your interface which has maybe a mic or guitar lead plugged into it without the guitar/mic on the other end. That becomes a nice noise antenna! And has happened to me before!  

Turns out it did need balanced TRS cables. Cleaned it right up, I'm amazed. I'll never make that mistake again. Thanks for all of your suggestions, this is a great forum.

I have those monitors, +1 on the balanced cables. Glad it's sorted.
Bibs