Unless mine is faulty, the Axe-Fx II is a very noisy unit...

Discussion in 'Digital & Modeling Gear' started by trazan, Feb 14, 2012.

  1. trazan

    trazan Member

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    I get no response in the Fractal forum, so....

    Any Axe-Fx II 4CM users in here? Setting up a loop within the Axe and going to the front of my amp. No effects, nada, just guitar > Axe-Fx > Out 2 to amp.

    I've made som comparisons, with straight guitar, and an Eventide Timefactor (which I thought was more noisy than I liked to begin with...)

    Part 1 - guitar > 65 Amps
    Part 2 - guitar > Timefactor > 65 Amps
    Part 3 - guitar > Axe-Fx 2 > 65 Amps
    Part 4 - guitar > Axe-Fx 2 with 12 dB boost/pad > 65 Amps

    At live loudness the Axe (Part 3) is like a friggin' waterfall...

    (You can really skip the last part, cause this is boosting the signal internally, hitting the DA at max level, and then padding the output...which leaves me with zero headroom in the Axe-Fx)

    [SOUNDCLOUD]http://soundcloud.com/runepune/axe-fx-ii-hiss[/SOUNDCLOUD]

    PS: whether a guitar is connected or not makes no difference. Nor does the input trim. I can even reduce the level digitally at loop send by 20dB...makes no difference....all the hiss seems to come from the output stage.

    So...faulty unit, or just the way it is?
     
  2. Scott Peterson

    Scott Peterson Staff Member

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    You have a ground loop or gain stage issue.

    It's not my forte though so I have no specific advice for you at this point.
     
  3. DougDoppler

    DougDoppler Member

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    Hey, sorry you're having a bummer experience. I'll be doing some FX loop with the Axe-FX in the next day or so and will be able to circle back with any suggestions. It sounds like there is a unity gain issue which may be part of why you're getting the hiss. The unit as I've used it direct thus far even with high gain models is REALLY quiet...


    Cheers ~ Doug
     
  4. trazan

    trazan Member

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    No ground loop and no gain stage issue. I repeat:

    PS: whether a guitar is connected or not makes no difference. Nor does the input trim. I can even reduce the level digitally at loop send by 20dB...makes no difference....all the hiss seems to come from the output stage.
     
  5. trazan

    trazan Member

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    I have no problems with it going direct, or using it in the loop. Also, stomps or amps within the Axe are not noisy at all. The problem is just an enormous amount of hiss at output 2 (efx send). Output 1 is fine into the front of the amp.
     
  6. shasha

    shasha Member

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    That sounds like noise that you'd pick up from unbalanced audio cables. Are you using the humbuster technology at all? It works fantastic and if it's ouptut 2 and you are using a straight TS cable that's the kind of noise you will get.

    http://wiki.fractalaudio.com/axefx2/index.php?title=Humbuster_cabling

    Wire it up like this and it should help knock it down by about -20dB (the noise, not your signal).
     
  7. PhilF

    PhilF Member

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    I don't know if this is a dumb question, but I didn't see it mentioned. Did you turn the output 2 knob up all the way on the front? If you aren't using any amp/cab models I believe it should be all the way up. So I'm thinking if its not then its actually taking the signal level of your guitar way down (closer to the noise floor...ceiling?).
     
  8. shasha

    shasha Member

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    Excellent point. If the signal being sent is low then of course it's going to be drown out by any noise along the way.
     
  9. trazan

    trazan Member

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    Humbuster takes care of hum, not hiss ;) But yes, I'm using a short "humbuster" cable.

    Again, the problem is output 2, and not 1. It's an output stage thing.
     
  10. PhilF

    PhilF Member

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    I don't know if this was in reference to my post (if not ignore) about the output knob, but output 1 and 2 have separate level knobs. Whichever one or ones you are using should be all the way up
     
  11. trazan

    trazan Member

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    The output knobs controls the analog output stage. They will lower the hiss as well as the signal when turned down. They will not alter the signal/noise ratio from the Axe. Yes, they are and need to be on full for unity gain.
     
  12. ejecta

    ejecta Supporting Member

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    I'm not a pro rig builder but I've dealt with groud loop hums quite a bit in the past and have gear like a Hum Eliminator and Hum X plug to deal with it. Those things have worked very well in the past to get rid of ground loop hums with other units hooking them up 4CM. However with the Friedman amp I have now... I've had zero success getting an AxeFX standard or my AxeFX2 quiet via 4CM even when I was able to take down the ground loop hum. I still had this whine noise in the back ground. Other users have had similar issues but I never found a an answer even on the Fractal forum. Never tried those cables that are supposed to help but dont see how they are any different than the other gear I have to deal with hum.

    Sorry I couldn't help you more but just wanted you to know I feel your pain.



     
  13. PhilF

    PhilF Member

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    Yea, you're right. Brain fart. Not sure how I thought the other way considering I adjust the output 1 knob quite a bit at home when the hours get a little later and notice exactly what you are talking about.

    Tonight when I get home from work I'll run the axe without anything in the chain...record output 1, then record output 2 (with an fx loop block) and see what the result is. It won't be into an amp, but it should still be able to test whether this hiss seems to be normal.
     
  14. Long2Play

    Long2Play Member

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    Maybe try and take take those two outputs to a mixer and see if they have different noise floors. You need to isolate the issue to the source. If output two is making more noise than output one, then it would suggest the issue in the Axe. If not, then the issue is either in cabling or some sort of impedance/grounding/gain level issue. At least that would get you some isolation to check for source issues. You might have already done that, just trying to help..
     
  15. trazan

    trazan Member

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    Yep, done that. The issue is with Output 2 (L and R), and not Output 1 (L or R). The manual seems to say that all analog outputs are the same, but this is definitely not the case with this unit.
     
  16. DougDoppler

    DougDoppler Member

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    Hey, just you might double check the firmware and update that, you never know:)
     
  17. Long2Play

    Long2Play Member

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    Ok cool sorry to hear you are having issues. I think why they say they are the same is they probably use a multi channel D/A to feed those outputs but you could still have analog issues in circuits past that. Or a code issue maybe. Doug's suggestion of firmware update is worth a try.

    :)
     
  18. trazan

    trazan Member

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    No, I mean same analog specs...impedance, dynamic range etc.

    Latest firmware.

    Again, the only difference is noise from the analog output stage. Output 2, that is.

    Had output 2 had the same lower noise floor as output 1, I would have been very satisfied. As it is now it's unusable.
     
  19. Scott Peterson

    Scott Peterson Staff Member

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    Have you contacted Fractal Support?
     
  20. trazan

    trazan Member

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    I probably will. I was just curious to see whether others had the same experience. If others can confirm that they have the exact same noise floor on output 1 and 2 I must suspect mine could be fixed.

    If you use the preset 383 BYPASS, no guitar plugged in, no boost/pad (I/O), no global alterations, both output levels full....then turning the amp up till you hear hiss - is the hiss level the same on output 1 and 2?
     

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