Hey everyone - I’ve been doing a lot of reading on the subject of digital and/or ground loop noise in DAW’s over the past week or so, to the point where it’s become a bit of an obsession. Trouble is there seem to be so many avenues to pursue, and I just can’t afford to pursue them all. So I’ll briefly explain my problem and if any of you know what may be causing it, throw ideas at me!!
So I use the following setup:
[::] PC (Phenom II X4 965BE, 4GB RAM, ASUS Mainboard, GeForce 8600 PCI-E GPU, Fatal1ty 750W PSU, 2x650GB SATAII HDD’s), Windows 7 64-bit Home Premium
[::] M-Audio FW410 (bus powered)
[::] M-Audio BX5A monitors
[::] Line 6 POD HD Pro & X3 Pro
[::] Samson Power Conditioner into which everything is connected
If I just use VSTi’s, or am mixing pre-recorded audio, everything is fine. With the exception of a slight buzz in my left monitor speaker (and the speakers are kinda old), the system is quiet and sounds great.
As soon as I try to connect the outside world to my interface, however, it gets noisy. As an example, my Line 6 PODs (guitar amp modellers) are connected to the line inputs. If I monitor those inputs, with no guitar plugged in and nothing in the patch whatsoever, I get a high pitched ‘whine’. If I add any distortion effects it’s even more noticeable.
If I record guitar direct into the instrument inputs of the FW410, the noise is also there, although in this case it’s probably picked up by the pickups as there’s no way for a loop to form between the guitar and the PC. But it’s interesting that the noise is the same whether it’s picked up by the cables in the form of a ‘ground loop’ or whether it’s by the pickups in the form of EMF leakage.
I often hear digital chatter in the signal too, like the sound of windows opening and closing on the screen, or the mouse moving. Even my hard drives spinning up and down. It all comes through loud and clear.
Interestingly the sound changes depending on whether or not I have my energy usage policy set to auto/power saver, or high performance.
I’ve only recently just got a new PSU, and I’ve run everything into a power conditioner. I’ve tried dedicated PCI FireWire cards (although the one on my mainboard is TI anyway). I’ve tried removing the graphics card, running one display instead of two, unplugging speakers, etc. Nothing helps.
From what I can tell, the noise isn’t there when the PC is in POST or BIOS. It’s as soon as Windows is loaded up that things start going crazy.
If it was just an EMF problem, it’d be easy enough to fix. I’d just move my base unit, or even compromise and sit at a funny angle to record. But that same damn noise is also in my dry guitar signal if I try to record DI in addition to Wet. So I can’t figure out where the hell it’s coming from. It just seems my setup is leaking noise all over the place. And I don’t know what to do or replace to fix it. Attached is a crude diagram of my setup.
Thanks so much for any input on this.