Noise in my setup...going crazy and need expert help!!

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.

My Setup.jpg721×890 39.3 KB

I am no expert (or even near) in this field, but since I am online at the moment, I figured I’ll butt in.

Do you need the other two devices connected to USB? Just wondering what they are used for since at least the audio is already serialized from X3 → HD → 410. Maybe you are using some software with them, but I had to ask…

Try running the FW410 on wall power instead, since it’s currently bus powered. Cannot hurt to try, if possible.

Maybe when trying the FW on self-power, try the entire computer on a different power outlet? (Just to test!)

Do you have any other devices (PCI cards, etc., other than graphics) connected to the computer?

Is the guitar is disconnected on the setup schematics? (Just joking, mate!)

What he said!

Also to add to the above, In the BIOS turn off everything to do with power saving and clock speed ramping.

No over-boost, C1 state off, spectrum spread off etc, etc… depending on bios.

Hey guys!

Firstly thank you for your replies - everywhere I go I seem to get no replies, so cheers for taking the time!

So I took the advice and just stripped everything down, explored all possibilities. And I think I’ve cracked it.

drum roll

Graphics card drivers! I installed the latest ones, and instantly my digital ‘chatter’ and ‘chirping’ was halved (although still present). Then I established that the power scheme had a massive impact on the noise, and also that it was highly directional, so I would need to move my tower. So between new GFX drivers, a relocated base unit, a power conditioner, more space between audio + mains leads, I’m not enjoying this kind of signal;

http://dl.dropbox.com/u/2996036/Golden%20Silence.mp3

This is going into an external amp modeller connected by both XLR and SPDIF (digital output being dry guitar only) and feeding the dry guitar into a soft amp modeller, which historically for me has always been an impossibility due to the amount of noise. It’s damn near perfect now!

My only remaining issue is that the central heating knocks out my SPDIF lock (yeah, I have a screwy house) but I’m hoping a 6-4-6 pin FireWire cable chain will remove the ground from the data connection, and I can power my interface from the wall socket instead. I’ve been told this can help.

Overall I’m very happy. I never would’ve thought that graphics card drivers could actually influence the amount of EMF it radiated. Who knew?

As an interesting side note, it’s funny that you should recommend disabling throttling/stepping/etc. as it was actually when my PC was running in Eco mode that it was the quietest. That was before I moved my tower anyway. Now I’m running in high performance mode and there’s barely a whisper.

Oh and Elektrobolt, the PODs have on screen tone editors/librarians, and the X3 also needs to be connected via USB to authorize the plugin version. It’s basically a way over spec’d hardware dongle!