Ultra noise at 3khz??

Rich G.

Rich G.

Experienced
I've noticed a distinct constant ringing coming from my Ultra. It's the same level regardless of output/output levels or ground lift position. At first I thought I was hearing things and then I measured it. The FFT is shown below:

2cyg0h4.jpg


The plot shows a distinct rise at 3khz. Has anyone else experienced this ringing at 3khz before?
 
I've seen that once when hooked up to a computer, there was a ground loop. If the computer and Axe-Fx are plugged into different outlets you can get a ground loop. If possible, use the XLR outputs and use the ground lift switch.
 
The setup used for the test was an Axe-FX Ultra into an A&H MixWiz board. Everything was plugged into the same outlet and fed off a plug strip.

For the measurement I fed the signal to a laptop from an Aux output. I used a Frequency Response Plotter to create the FFT.

I did some additional testing tonight with the following results:

(Y) = Yes, noise is present.
(N) = Noise is not present.

(Y) 1. XLR OUT of Axe to XLR IN on board. Axe grounded.
(Y) 2. XLR OUT of Axe to XLR IN on board. Axe ground lifted.
(Y) 3. XLR OUT of Axe to XLR IN on board. Axe grounded. XLR cable ground lifted.
(Y) 4. XLR OUT of Axe thru Ebtech Hum Eliminator to 1/4" IN on board. Axe grounded.
(Y)* 5. 1/4" OUT of Axe to 1/4" IN on board. Axe grounded.
(N) 6. 1/4" OUT of Axe thru Ebtech Hum Eliminator to 1/4" IN on board. Axe grounded.
(N) 7. 1/4" OUT of Axe thru Behringer DI to XLR IN on board. Axe grounded. DI grounded.
(N) 8. 1/4" OUT of Axe thru Behringer DI to XLR IN on board. Axe grounded. DI ground lifted.

* Noise was 60 cycle hum, not 3 kHz whine.

Also note that tests were performed with/without board phantom power applied.

So, I believe I can conclude that the whine is present only when using the balanced outs of the Axe.

I haven't concluded that this is/is not a ground issue. I'm in an old house and know for a fact that the outlet used is ungrounded. I've yet to dig out an extension cord to go into a grounded outlet.
 
I experienced the same thing with the XLR outs (ground lift ON and OFF, tried both).
I was trying different things two days ago (I never thought the problem was the Axe), and then I tried the 1/4" OUT. Voilà. That medium-high noise (I didn't measure it with a computer as you did, but could well be around 3KHz) was gone using the 1/4", but present in the XLR outputs (nevermind the ground lift).
I thought it was the cables, that's why I didn't write anything here, but your post shows exactly my problem.
 
First time I powered up in my 60 year old house, after getting the studio grounded, I had to double check to see if the power was even on because it was dead silent. I can take the same gear into my kitchen (ungrounded 2 prong) and it snap, crackles and pops like rice crispies. Until you ground it properly (IMHO) you are spinning your wheels. Not to mention the safety of you and your gear.
 
javajunkie said:
Did you have the phantom power on?
Click to expand...

Tests were done with and without phantom power from the board.

mwd said:
First time I powered up in my 60 year old house,
Click to expand...

My house is 80 yrs old and the wiring is pretty bad. I plan on retesting after running an extension cord to utilize properly grounded plugs.
 
supersecretjim said:
Just curious, are you using a power conditioner in your setup?
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Yes, The Axe is plugged into a Furman PM-8 Series II conditioner.

For those following the thread, I plug everything into a properly wired outlet and the results did not change.

For further testing, I'll check for the noise at this weekend's gigs which are at two separate venues.
 
As you are going into more complex diagnosing keep these in mind.

Is this sound present with and without your guitar? Other guitars?

Yep' take it to as many locations (new buildings a plus) as possible.

Get a cheap tester and confirm. 3 prong plug doesn't necessarily equal proper wiring or ground. Good for the gig bag as well.

outlet_test.jpg


Otherwise sounds like Fractal Support is needed.
 
+1 for the electrical plug tester thingy. I *never* plug my Ultra into any receptacle until I've gotten those two yellow lights to indicate an all-clear power supply.

Daniel
 
mwd said:
Is this sound present with and without your guitar? Other guitars?
Click to expand...
The sound is present with and without a guitar present.

Yep' take it to as many locations (new buildings a plus) as possible.
Click to expand...
I'll be playing two different venues on opposite ends of town Fri & Sat. That will be a good test.

Get a cheap tester and confirm. 3 prong plug doesn't necessarily equal proper wiring or ground. Good for the gig bag as well.
Click to expand...
I always bring one with me and use it when playing new venues to check things out. I identified a problem at one place where they had the line/neutral reversed. I told them they needed to fix it as it is a violation. I ended up running extension cords to good outlets which were like 50' away. Went there a month later and they had done nothing to fix it. The guy called over his "electrician" who proceeded to tell me my yellow tester was bad. We never played there again.
 
What does this noise sound like, exactly? I've been having noise issues with my Axe-FX rig since I put it together. Bad power is the only thing I haven't been able to rule out yet (I have a power conditioner, but if there's not a proper ground, that would explain why the conditioner wouldn't help), though I'll be setting the rig up somewhere else tomorrow evening. I'm getting it with all of my rigs, though, so if you only have this issue with the Axe-FX, it might not be similar after all.

Edit: Nevermind. I just looked back again and saw you're talking about a constant ringing, which doesn't sound like what I'm experiencing.
 
Tom said:
What does this noise sound like, exactly? <snip>
Edit: Nevermind. I just looked back again and saw you're talking about a constant ringing, which doesn't sound like what I'm experiencing.
Click to expand...

It's a constant "wheeeeeeeeee" at 3khz, but there's another component to it. I hear a "tick-tick-tick" once every 750ms or so.

I listened for it this weekend at both places and did not hear anything... however, the sound is rather faint and the noise floor of the room/crowd was certainly loud enough to mask it.
 
You had mentioned you were going to plug in an extension cord and it still made noise. Was it in the same location that gave you noise before? Reason asking is it sounds like a monitor or fluorescent or cell phone interference.
 
Make sure your not pluggin into a circuit that has a refrigerator, wahser/dryer, etc, on it. Those can creat noise.

Wall warts near your cables can create noise as well.
 
I know what noise you're talking about. With the gate off and the master and gain cranked, you can hear it. Sounds very digital. However, unless the gains are cranked with the gate being off the noise is pretty much unnoticable with normal ambient noise. Besides, how much more noise do you get from a real cranked tube amp vs the virtual cranked model of the Axe-Fx. Seem's pretty understandable to me. ;)
 
I just discovered a similar (or the same?) issue:
Dial up the JTM45, turn the Bias up and change the TF Lo and Hi Frequencies and there are sine waves coming out of the Ultra (frequencies change when altering the parameters described above).
I haven't tried with other amp models yet.

Sounds like a bug to me...
 
merlin17 said:
I just discovered a similar (or the same?) issue:
Dial up the JTM45, turn the Bias up and change the TF Lo and Hi Frequencies and there are sine waves coming out of the Ultra (frequencies change when altering the parameters described above).
I haven't tried with other amp models yet.

Sounds like a bug to me...
Click to expand...

Sounds like you are taking the amp way out of spec to me.
 
merlin17 said:
I just discovered a similar (or the same?) issue:
Dial up the JTM45, turn the Bias up and change the TF Lo and Hi Frequencies and there are sine waves coming out of the Ultra (frequencies change when altering the parameters described above).
I haven't tried with other amp models yet.

Sounds like a bug to me...
Click to expand...

If you set some of the parameters to extremes like this you can actual cause the amp model to go unstable (just like a real amp). The Stabilizer switch can be used to stabilize the amp. This isn't considered a bug, you just have to use common sense when setting parameters.
 
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