Be aware of the digital sonic artifacts (aliasing) in your KPA!

    Quote from professortweed

    haven't heard the aliasing myself. Radley, do you hear it on your Lancer profile at all?


    Aliasing has never been a problem for me with the Amp block (that's someone else's complaint) - I'm referring to the higher gain OD stomps. The noise problem I refer to is usually with the stomp compressor on (medium settings) before the Amp block - the NR reduces the hiss, but there are still 'crackles & sputters' that come through unless you set the NR pretty high, which kills the natural sustain of your instrument.

    All modelers known to man 8o

    Quote from Radley

    there are still 'crackles & sputters' that come through unless you set the NR pretty high


    I agree with Hadley on this. I have noise that comes and goes. It's not a deal breaker, but it would be nice to eliminate it.

    Go for it now. The future is promised to no one. - Wayne Dyer

    Hi folks,



    I for my part can hear the aliasing (starting around the 17th fret on the high e-string) quite well - especially when reverb and delay are turned off. But you have actually to search for it (that is to say you wont hear it when you just play the guitar) and as it is quite discreet in the background it is for me not a big nuisance.



    Anyhow I would still prefer it if this issue could be solved in a firmware update.

    Don't know if this has to do with this topic but...
    Since I use the kpa my guitar is far more sensitive to noise it picks up from dimmed lights
    Allways had to adjust my noise gate
    But with the kpa I have to drastically turn down the gain sometimes

    As I already said the aliasing is not audible if you just play the guitar. You have to let the single notes ring (high e-string starting about the 17th fret) - then the aliasing is audible quite far in background.
    So it is not a big issue and for me absolutely no dealbreaker - but the KPA would be even nicer without.


    By the way - I have tried with different guitars and all other electrical gear turned off - it is no interference form outside.

    Quote from and44

    could it be interference from moniters?, light dimmer switches and sorts of things like that!


    The noise I hear is what I would usually associate with a solid state amp going bad, kind of a low pitch crackly sound. It appears out of nowhere and disappears when I play. Odd stuff, and definitely not the kind of noise you get from electrical interference. 8|

    Go for it now. The future is promised to no one. - Wayne Dyer

    Quote from fernandes

    As I already said the aliasing is not audible if you just play the guitar. You have to let the single notes ring (high e-string starting about the 17th fret) - then the aliasing is audible quite far in background.
    So it is not a big issue and for me absolutely no dealbreaker - but the KPA would be even nicer without.


    By the way - I have tried with different guitars and all other electrical gear turned off - it is no interference form outside.


    I've tried what you've suggested and I'm still not hearing it, all I hear is pickup flutter due to my guitars being poorly set up (I'll get the same noise with a real amp or other modelers, sounds like a ring modulation warble, I can provide an example of you want). Could you record and post what it is you're hearing?

    Quote from Zappledan

    The noise I hear is what I would usually associate with a solid state amp going bad, kind of a low pitch crackly sound. It appears out of nowhere and disappears when I play. Odd stuff, and definitely not the kind of noise you get from electrical interference. 8|


    Hi Z.


    Sorry to go about this, but this is EXACTLY the same probs I used to have, took me ages to discover.. turned out to be a dimmer switch that went bad, replaced with a normal on/off switch and all was ok, since then never had the same problem...


    I too had weird noises, soon as I touched the strings it went.. would hum one min, buzz the next.. used to drive me a bit nuts.. - silly suggestion, turn of all the lights in the room.. and in fact the house!!... also if your fridge power supply is near will casue simular results..


    I hope Im wrong here for your own sake.. but I feel your pain mate!
    A

    Quote from Zappledan

    The noise I hear is what I would usually associate with a solid state amp going bad, kind of a low pitch crackly sound. It appears out of nowhere and disappears when I play. Odd stuff, and definitely not the kind of noise you get from electrical interference. 8|


    Are you going SPDIF?

    I think the aliasing issue can most easily be heard when using headphones - that way I discovered it.
    And I am quite sure that it is no string flutter, pickup noise etc. as it reminds me of the aliasing noise my old modeler made - even though with the KPA it is much more in the background. If I find the time I will record and post it.

    Quote from Per


    I've tried what you've suggested and I'm still not hearing it, all I hear is pickup flutter due to my guitars being poorly set up (I'll get the same noise with a real amp or other modelers, sounds like a ring modulation warble, I can provide an example of you want). Could you record and post what it is you're hearing?


    Here is a reminder of what this thread is really about: KPA Aliasing Example
    I am reposting this sound file that demonstrates the amp profile aliasing with additional aliasing from a dist stomp (both dist stomps and amps will make this noise individually, but together it's obvious enough for anyone to hear).


    Thanks A. I've definitely decided it's coming through the PUPs, so not a KPA noise issue. So many possibilities in this old house, so I'll probably never find the source. Oh well.

    Go for it now. The future is promised to no one. - Wayne Dyer

    I'm probably deaf, but I still hear nothing that you'll not get from an amp....but then, I'm a low gain guy.... ?(

    "Music is enough for a lifetime, but a lifetime is not enough for music" Serghei Rachmaninoff


    There's two things I hear.


    1) Ghost harmonic, potentially could be aliasing or just too harsh compression attack (you can also get such notes with a real amp). You have to turn the sound up, basically the sound is somewhat like a ballbearing rolling on a piece of board behind the main sound.


    2) Bloom (most likely sag in the amp, or the effect of the natural compression).

    Edited once, last by Per ().