What the hell is this noise?

I wonder just how many have the same issue?

I am thinking This is a design issue. Could the fan be relocated so as not to interfere with the electronics and still be effective. The case is sealed so what is tan actually doing? I would expect a convection flow requires a vent.
 
rmbaylin said:
I wonder just how many have the same issue?

I am thinking This is a design issue. Could the fan be relocated so as not to interfere with the electronics and still be effective. The case is sealed so what is tan actually doing? I would expect a convection flow requires a vent.
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I have both the whining and heartbeat. Always have. I consider it very low level background noise; not noticeable for live or recording.
 
So its not just mine and it seems like few still have this issue even with fan replacement. The fan motor must be causing EMI and the circuity is picking it up. The noise is simply amplified by gainier patches which is why different patches are worse

My guesa is The noise has nothing to with grounding. Its all induced so relocation or rejection of the source is the fix.

Can the fan be relocated inside the case, other than over the processor? Would this be safe?

Is there shielding that culd be put in like the foil used in a pickup cavity? Is there any potential issues adding a layer of foil cage over the CPU or under the fan.
 
If the fan is the actual source there is more than enough room inside of the case to construct an air duct of some kind. Basically locate the fan away from the circuitry as best as possible and then use a NON CONDUCTIVE vent to route the air to the heatsink of the DSP. Automotive ducting works really good for this stuff.

Just remember that you aren't going to have the cfm at the chip so you may need to get a stronger fan. Of course since you are moving it away from the heatsink you could get just about any size that would fit in there physically.

I will say this though; I get a similar noise in my computer. If I mute the line input it is gone, but when I move my mouse or use the scroll I hear it (this is without the AFX even connected to the machine).
 
Played some more with mine and a unshielded Strat. It did have a Suhr BPSSC installed, but cavities were unshielded. I used a non-BPSSC strat the other night (but shielded), there was a little 60hz hum audible.

Quiet. We're talking about playing at bedroom + levels, probably talking very loudly.

Mainly playing with Raca's Plexi2(changed to JTM-45 model) patch and Enzo's Tri-Chorus patch. One thing I did notice in the past is when the bright switch parameter on the amp model was engaged, noise floor went up significantly, so lowering mids/Bass and boosting treble/prescence, along with increasing gain seemed to reduce the noise floor significantly.

Not having the hum definitely made things sound better to my ears. I was about to pop for a couple sets of EMGs.
 
rmbaylin said:
Now listen carefully.. WHAT DO YOU HEAR...
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Broadband (white) noise at a very low level (i.e., I have to put my ear right up to the speaker to hear it). Most of that is input noise in the powered monitor's amp section.

NOW WHAT DO YOU HEAR? I hear everything LOUDER, as is expected.
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Yep. That's it.

Now there is what I call the "digital whine" noise on top of the hiss
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Nope. I've never heard any hint of that noise from my Axe-Fx.

and the 'heartbeat' noise.
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Nor that.

Adjusting the SAG makes the noise more prominent.
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All that says is that the noise is injected prior to the amp block.

Is your AXE 'DEAD QUIET' (except for the floor noise - ie the hiss of the speaker's amp)?
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Yes. Absolutely.

Something is wrong and I think its in the AXE.
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Seems like a possibility to me. The noise sounds like bleed from a clocking circuit, which could be caused, for example, by a defective opamp in the Axe-Fx input.

Its just to see if there a digital artifacts or aliasing or something in the AXE circuitry creating this noise.
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Aliasing does not create noise in the absence of signal. The fixed frequency of the "whine" is an indication that there's unwanted clock signal getting into your audio signal chain.

I just need to know is it mine or is this something IN THE AXE DESIGN.
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It is not.
 
Here is a clip of mine.

The signal chain is shielded Strat > Korg tuner pedal > AFX Ultra > MOTU HD192 > Sonar 8.

The tuner is running on batteries. If I plug straight into the front input, I do not have the problem. If I use any pedal at all, the whine appears at sits a constant -33dB whether the pedal is powered with batteries or a power supply.

As I said before, it doesn't matter if the output is digital or analog. It doesn't matter which guitar I use or which cords I use. It doesn't matter if I run it with or without a power conditioner, which outlets I use in the house, etc. Lifting grounds makes no difference. It always does this and always has.
 
stvnscott said:
Here is a clip of mine.
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I downloaded that and did a spectral analysis:
[attachment=0:1wrpz2l4]whine.jpg[/attachment:1wrpz2l4]

These are all harmonics of 60 Hz. Something in your signal chain is generating very high levels of upper harmonics of the AC power frequency - with the strongest being the 480-Hz (eighth) harmonic - and something else is picking up these frequencies.

The tuner is running on batteries. If I plug straight into the front input, I do not have the problem. If I use any pedal at all, the whine appears at sits a constant -33dB whether the pedal is powered with batteries or a power supply.
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That would indicate that the problem is not being caused inside the Axe-Fx.
 

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Hmmm... It appears I need to take a closer look at how my studio is wired. Thanks for that analysis.

To your second point: yes, that is obvious since it manifests based on what I plug into it. The point I failed to articulate well is that none of my other gear does this (11R included), which leads me to believe the AFX is more sensitive to it.
 
My noise came from my computer. It was identical to this noise, and very annoying. I researched everything, replaced every cable, every light bulb even the cat litter. Nothing worked. One day (I beta test computers and build them too), I switched my DAW interface (Digi 002) over to a Mac Pro, fired up Pro Tools and - NO NOISE. None. Dead quiet, even on very, very high gain metal patches.

I switched it back to to one PC and then to another PC built in the same way but using very different components (CPU, PSU, etc). No matter what do (seriously) I cannot get the PC DAW to be as quiet as the Mac. I even bought one of those $70 hum cancelation units that plug into the wall, and your unit into the hum canceler. No relief.

Switched it back to the Mac - bingo! Better, quieter, more enjoyable pure tone.


I've tried everything I can think of to lift the ground of the PC's, but it ain't workin', and I don't know why.


My $0.02
 
diggi said:
My noise came from my computer. It was identical to this noise, and very annoying. I researched everything, replaced every cable, every light bulb even the cat litter. Nothing worked. One day (I beta test computers and build them too), I switched my DAW interface (Digi 002) over to a Mac Pro, fired up Pro Tools and - NO NOISE. None. Dead quiet, even on very, very high gain metal patches.

I switched it back to to one PC and then to another PC built in the same way but using very different components (CPU, PSU, etc). No matter what do (seriously) I cannot get the PC DAW to be as quiet as the Mac. I even bought one of those $70 hum cancelation units that plug into the wall, and your unit into the hum canceler. No relief.

Switched it back to the Mac - bingo! Better, quieter, more enjoyable pure tone.


I've tried everything I can think of to lift the ground of the PC's, but it ain't workin', and I don't know why.


My $0.02
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You probably need to move your firewire card (if it is not mounted on the motherboard) further away from your video card or power supply. You are probably picking interference from something inside the case. Usually moving components away from each other or moving cabling inside the box will fix that.
 
Merci' Sean,

Unfortunately, the approved Gigabyte boards I am using for both PC's also have approved on-board FW that work well with my 002 setup. I will attempt to move graphics cards on both systems (ATI HD4650 1024 cards) further away from the CPU, and the USB FW cluster. My sense is that this will not help, but I am really hoping I am wrong :)
In doing so, I may also see a degradation in performance from these GPUs.


I'll report back....
 
Well... I am sure the digital noise coming from the fan itself - this means either the fan is defective, or something in the axe is defective...

I am sending the unit back to Fractal, and hoping it just a rogue fan, and not anything to do with the Axe 'guts'.

I did play for a little while with the fan disconnected at practice and it was nice to hear true guitar tone w/o the noise. Got worried, so I hooked it back up after a few minutes.
 
I also get a high pitched whine every time my rack is plugged into my computer. In my case it's definitely a ground loop.
 
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