4CM noise, any other setup has no noise

M

MetalMan

Member
Hi, my Axe Fx 3 Mk. 2 is very weird. I want to use the 4cm in order to get the most of the fx processing, and because that way I can also use some clean patches via IN1-OUT1 (essentially making it an A/B switch between my analog rig and a a digital rig).

When I use it only as post, or only the fractal or the amp (no fractal), there is no noise (I have not tried pre).

However, the 4CM is extremely noise, and I don’t know why.

I have checked the presets, the signal chain is ok (correct INs and OUTs). The noise is not from anything other than the fractal in 4cm.

The noise is high-pitched white noise, but also, just as incredibly irritating, is the “residue” from when I finish playing a note (a high-pitched noise, as if feedback).

Again, this is ONLY in 4CM. I don’t know why. Please help.

My signal chain:

Guitar > Axe FX IN1 > OUT3 > Boss SD-1W > Boss NS-2 > Amp input > Amp FX Send > IN4 > OUT4 > Amp FX Return > Amp Speaker Output > Two Notes Torpedo Reload (-15DB) > Focusrite Solo (XLR In) > USB > Reaper.

[I use the focusrite solo cause I like it, it works, and eliminating it by using a fractal does not work for me. Also, not the issue]
 
I often have issues like this with my Axe FX that 99% of gear is dead quiet with. Even with humbuster cables I still often need to use line isolators to properly eliminate any ground loops. I suppose the amount of I/O available on the Axe FX means it might be more prone than a lot of gear but it also seems to be fussy.

I’d try playing around with plugging in different sockets and seeing if anything in your room makes a difference. Also check all your balanced and unbalanced cables to see if anything helps.

A lehle line isolator or 2 is a good investment to call upon when unexpected noises arise, IMO if you have ruled everything else out I’d grab those and you’ll be sorted.
 
MirrorProfiles said:
I often have issues like this with my Axe FX that 99% of gear is dead quiet with. Even with humbuster cables I still often need to use line isolators to properly eliminate any ground loops. I suppose the amount of I/O available on the Axe FX means it might be more prone than a lot of gear but it also seems to be fussy.

I’d try playing around with plugging in different sockets and seeing if anything in your room makes a difference. Also check all your balanced and unbalanced cables to see if anything helps.

A lehle line isolator or 2 is a good investment to call upon when unexpected noises arise, IMO if you have ruled everything else out I’d grab those and you’ll be sorted.
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I forgot to mention that I also have a Furman P-1800 AR, which my entire gear (except my laptop) is plugged into. I have tried switching between sockets, but no dice.

I am thinking about getting an Iso Box, it would just be annoying to have to spend more money…but everything else is now a sunk cost, so I may as well in order to not render the gear useless…
 
What amp?

I seem to recall a couple of previous posts about that type of noise with specific amps.

Also, have you tried Humbuster cables on the Axe Fx outputs?
 
unix-guy said:
What amp?

I seem to recall a couple of previous posts about that type of noise with specific amps.

Also, have you tried Humbuster cables on the Axe Fx outputs?
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Marshall JCM 800 reissue (2203x).

No, I have not, but I fail to understand why these would change things if the noise is only in the 4CM setup, but not in the post-fx only setup.
 
MetalMan said:
I forgot to mention that I also have a Furman P-1800 AR, which my entire gear (except my laptop) is plugged into. I have tried switching between sockets, but no dice.

I am thinking about getting an Iso Box, it would just be annoying to have to spend more money…but everything else is now a sunk cost, so I may as well in order to not render the gear useless…
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it is annoying, and it doesn’t seem like it should be necessary but honestly, audio is fickle and unpredictable like that and if solving it is as easy as adding an isolation transformer then things are going pretty well. I do wonder if properly isolated transformer balanced I/O would significantly affect size/cost/performance of the unit (even if just on a couple of ins and outs). I’m yet to find a situation where humbuster cables have done much for me but i’m happy to have them around in case the situation arises.
 
I set the output3 (cable out to ext amp input) boost/pad to -6 in setup which tames noise quite a bit - be aware though, that increasing that boost/pad reduces out3 headroom (I never go more than -6). ISO transformer just before ext amp input has also worked for me (get a good one - ie: Radial) - humbuster on cable 2 to amp input also helps, and I find turning on the input block gate on cable3 (from Amp send) works well
 
There’s a Leon Todd video that shows a few adjustments for best practice for this. There’s a setting that adjusts the noise floor or signal to noise ratio, I can’t remember what it is. But it helps big time. I think it’s in the I/O screen, there are a few adjustments on input Pad and output levels.
 
sprint said:
I set the output3 (cable out to ext amp input) boost/pad to -6 in setup which tames noise quite a bit - be aware though, that increasing that boost/pad reduces out3 headroom (I never go more than -6). ISO transformer just before ext amp input has also worked for me (get a good one - ie: Radial) - humbuster on cable 2 to amp input also helps, and I find turning on the input block gate on cable3 (from Amp send) works well
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I’ve tinkered with that (the output 3 pad/boost), did not do a thing for my issue
 
I am curious - in my signal-chain, where would I put a lehle p-iso? And which of the 2 is the input and which is the output (or does it not matter)?
 
Just a thought... on my setup, my amp/FM9 are on a different outlet than my mac. Simply unplugging the USB cable between the two eliminates a bunch of noise when doing 4cm with an amp. I tolerate the noise when I want to use FM-Edit, but then I unplug the USB when I am just playing.
 
InsideOut said:
Just a thought... on my setup, my amp/FM9 are on a different outlet than my mac. Simply unplugging the USB cable between the two eliminates a bunch of noise when doing 4cm with an amp. I tolerate the noise when I want to use FM-Edit, but then I unplug the USB when I am just playing.
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Same here…USB and computer noises can be quite the gremlins
 
IMHO, best practice here would be to bypass (unplug) each peripheral device one by one to find where the noise is being introduced.
 
Since nobody has asked, Old SoundMan will: what brands/types of cables are you using and what are their lengths? How are all your various pieces of equipment mounted? What type(s) of computer(s) mounted where?

Audio gear — especially the good stuff like your Fractal(s) — isn’t “fickle”. “Ground loops” and many objectionable noises are often the byproduct of compromised mounting, sub-par interconnection cables and/or cable routing… as well as not following proper electrical distribution/grounding techniques.

While using isolation transformers will sometimes effectively mask noise issues, I’ve had better results working to figure out the problem vs. “band-aid” solutions — and all but the best transformers can have their own sonic characteristics that can affect the “tone” we all spend so much time-effort pursuing.
 
I have had a similar problem (although FM3) with using 4CM and my preamps - the only thing that has worked for me was from the FM3 input -> spdif output -> Benchmark DAC-1 XLR output ->preamp -> FM3 input 2

If I use external pedals with the preamps then it is quiet.
 
I have found that many amps are particularly sensitive to electrical interference through their Send/Return effects loops. This even happened when the Send and Return were simply connected with a patch cable. There is no problem with these amps when effects are routed through the front end and the loop is not used. I have a Blackstar that went back to the manufacturer for this issue, and came back the same. It was only when I tried the amp in another location, and the noise disappeared, that I realised that RF interference was the problem.
I eventually tracked the cause to power line ethernet networking and, to a lesser extent, the power supply to an electric reclining chair! The noise only occurred when the Send/Return were connected together, even with just a patch cable.
I later bought a PRS amp that immediately exhibited the same problem, but much worse. I had already eliminated the interference sources that had affected the Blackstar, but the noise from the PRS was so loud that it was impossible to talk over. Again, this was only when the loop was connected. I couldn't face another interference chasing marathon, and the PRS amp went back to the shop (where it worked perfectly).
This may, or may not, be the cause of your problem, but it is easy to check. Just replace the part of the rig that passes through the loop with a simple patch cable, and put everything through the front end. If the noise is still present, but disappears when the patch cable is removed, then susceptibility to RF interference via the loop is the cause.
 
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touch33 said:
Since nobody has asked, Old SoundMan will: what brands/types of cables are you using and what are their lengths? How are all your various pieces of equipment mounted? What type(s) of computer(s) mounted where?

Audio gear — especially the good stuff like your Fractal(s) — isn’t “fickle”. “Ground loops” and many objectionable noises are often the byproduct of compromised mounting, sub-par interconnection cables and/or cable routing… as well as not following proper electrical distribution/grounding techniques.

While using isolation transformers will sometimes effectively mask noise issues, I’ve had better results working to figure out the problem vs. “band-aid” solutions — and all but the best transformers can have their own sonic characteristics that can affect the “tone” we all spend so much time-effort pursuing.
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I agree, there are some high end cables and some regular cables, but I do not think they are the issue because, again, the setup has no noise if you use the Fractal only as a Post-processor or if you bypass the Fractal at all. Also, using a pedal in the fx loop (the exact same setup sans axe fx) yields zero noise. Besides, it cannot be a power issue since everything is connected to a Furman P-1800AR, which regulates current and voltage.

So I understand ground loop can be here and there, but I genuinely think the axe fx is the variable introducing the noise.
 
I’m inclined to agree that it’s not AC power related b/c you describe the noise as “high-pitched white noise”. Assuming I’m correct in that the noise is a constant (not modulating in any way) I’m inclined to think it’s RF interference from a computer/processor penetrating your cabling. If you’re removing cables when you hook things up and it’s not noisy I’d suspect the removed cables first. Single-conductor (unbalanced) cables that use the shield as a signal-carrying conductor can be primary culprits for RF leakage.

Does the physical location of your components change when you do/don’t have noise? This can also affect RF interference issues…
 
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