Posts by Laimon

  • 2 broken 12" speakers in the same day with powerhead¡¡¡¡¡¡¡¡gggggggggggCAUTION

    Quote from estocastico7

    the mesa boogie 1x12 is 60w......yes you can damage,i don´t know the limit,but i broke two speakers with the powerhead,now i have more caution.......


    however in 100 watt valve amps....where is the limit to drive a 60w speaker???? ?( ?(

    True, but is also true that, while it can't be done with a normal amp, a software based product like the Kemper could have a user-settable parameter specifying the wattage of the cabinet in use, and enforce a limit of volume based on that. At the moment I use it with a 20W tube poweramp, at home I never set it past 9 o'clock, and live I think I went as far as 1 o'clock (on a 2x12 cab), I really wouldn't see the need to push the volume much further

  • 2 broken 12" speakers in the same day with powerhead¡¡¡¡¡¡¡¡gggggggggggCAUTION

    This topic puzzles me...well, it is clear that a 600W@8Ohms can kill a speaker of lower wattage, but when does it?
    That is: is there a way to know the maximum volume you can bring your poweramp too, before your speakers are damaged?
    Or, even better is there an option in the Power Head/Rack to specify the cabinet wattage and thus limit the maximum volume that you can set on the kemper?
    I, for instance, own a Mesa Mini Recto 1x12, this one: http://www.mesaboogie.com/Prod…Recto1x12-SlantCab-LG.htm
    and I would gladly avoid damaging it, if possible :D

  • The Aliasing Problem

    Update from Kemper support:


    I managed to recreate the situation on my system and forwarded the case to our developers.
    Please wait until i get their comments.
    As soon as i have new info i will get back to you.
    Thank you for your patience.



    So prompt and kind intervention. Another plus for Kemper!


    Now we wait and see :)

  • kemper through roland ac 33

    I don't know much about the roland ac33, but I don't see any send/return to effects, hence you'd have to pass the output of the Kemper through the preamp section of the Roland, and that'd color the sound quite a bit.

  • Looper

    Also, it would totally make sense to have it automatically placed for each rig at the end of the chain, so to be always "looping ready", with the possibility though to select it as a stomp so to change the placement.
    Something like a minute or 2 (at least), and the possibility to store the loop. Ah, wouldn't I love that

  • The Aliasing Problem

    Quote from deadpan

    I had had a problem like this and a system reset cured it.

    Tried resetting this morning: didn't change a thing. (It would have surprised me a lot if it did)

    Quote from db9091

    I have read that when this happens, as it does especially to acoustic playing musicians, they use Crazy Glue to glue the skin back to the nail with great success.


    There is even a form of it used essentially in surgery to close wound in a stitch less way.


    Have you tried it? Might really help you, and sorry you have to go through that. I have been through it once and it is very painful.

    Oh man, if that would work I'd owe you for the rest of my life!
    Each time I have to stop playing for some 2-3 days, and even when I restart for some time I need to be all cautions with vibratos lest the wounds would open again :(
    But is this Crazy Glue the generic supertough glue that you can find anywhere? I would be a bit concerned whether it's totally safe to put that on something that is quite like a wound (even though it doesn't bleed).
    Maybe I can double check with friends of mine that are doctors.

    Quote from DukeOURL

    ma that clip is about as fizzy as it gets.. so I've got a couple of passages on a track or two that sound similar.. guess I'm having an aliasing issue as well. Thanks for point ing it out.. What I've don in the past is switch guitars.. it seems more dominant on my cobra, which has a 6 ohm front pickup.. when I move to a gibson with humbuckers, the issue seems to go away.. (using the same profile)

    Yes, it is a very fizzy rig. I would probably never use that one particularly for myself, but still I go very high gain though not as "modern".
    If you're having aliasing or not, you shouldn't judge from the fizziness of the rig (though those are certainly the conditions where you could expect it the most) but from listening. Try plugging it on a guitar cab, cab sims off, and play a single, sustained high note with some vibrato, that's when you hear the craziest wobbling. If you don't hear anything there, you should be fine. If you do but it's fairly subtle, you might be ok when cab sims are on (but do check closely with headphones on your record).


    Certainly the guitar/pickups used is a factor, but I find it really hard that it would go away altogether just changing guitar. I have tried with the two Yamaha Pacificas (used for the clips, DiMarzio Air Classic and DiMarzio Evolution respectively) and then with an Ibanez J Custom 7 string, with some custom DiMarzio PafPro (or similar)...the latter showed less signs of aliasing, in line with the fact that it is a much less bright sounding guitar, but nonetheless it was still there and not very attenuated either.

  • The Aliasing Problem

    Quote from Michael_dk


    Do you have the possibility to try S/PDIF?


    No wait... I'm thinking that maybe the problem COULD be from the audio interface, but did you say you experienced the same through a real cab/FRFR (i.e. without going through the interface)?

    Yes, both on record and (most of all) "live" (well, in my room, but going to an actual guitar cab). No AI in between.

  • The Aliasing Problem

    Quote from deadpan

    I had had a problem like this and a system reset cured it.

    Seriously? That would be gorgeous. I guess I'll ask confirmation with their support team first (in case they actually need to analyse the setup and I can provide some helpful info)

  • The Aliasing Problem

    Quote from Michael_dk

    Well... That does sound like aliasing, doesn't it...


    Did you record through the SPDIF or the analogue outs?

    Analog outs. The "cabbed" version from the Main out, the "uncabbed" version from the Monitor out.
    I am actually surprised that I am the only one to bump into this problem...noone using it for high-gain sounds?

  • The Aliasing Problem

    Quote from paults

    Agreed about the high end, from an artistic standpoint. I thought you had boosted the treble, to make the issue easier for us to hear. Is this a single coil, low output guitar?


    I normally use a PA speaker. If it is easier to hear when using a guitar cab, have you tried using profiles that were created without a cabinet, with the Kemper cab "on"? If not, try some of those, and see if that solves your problem.


    Culd the distortion be coming from overdriving the input to your power amp with the Kemper?

    No, didn't boost the treble, I left exactly as it was in the profile. (which again, was chosen for the extreme signs of aliasing)
    What you heard before was a DiMarzio Evolution bridge humbucker, so not even low output. Anyway, I put new clips (see below) also with lower output humbuckers. I guess the alder gives it a very bright tone.
    I have used "preamp only" profiles: one I created myself based on my head, and that - though not completely alias-free - behaves fairly well; the others I tried, downloaded from the Kemper webpage, also show a lot of aliasing (the dirty tones, of course).
    Finally, I am not overdriving the power amp, and the clips prove it, as I recorded them directly from the Kemper's outs.


    Now, update:
    I made new clips. Hum-free this time, which makes the aliasing really easy to hear this time, both with and without cab simulation.
    I used two Yamaha Pacificas, one with a DiMarzio Air Classic pickup (bridge, medium gain) and one with a DiMarzio Evolution (bridge, high gain), and I made a clip for each combination guitar-cab sim on or off.
    I loaded the clips here: https://soundcloud.com/simone-frau-2/sets/new-alias-clips
    and you can also download the wave versions from here: https://drive.google.com/folde…94cS1KUFNCNEU&usp=sharing


    I tried profiling a lowpass filter (plugin on my pc), the result did not help much: although the filter was set at 20kHz, the overall sound appeared somehow a bit muffled and still retaining the aliasing.
    But this is a hardly reliable try:
    1) the PC plugin has a noticeable latency, the profiling might all broken in such a scenario I believe
    2) the cab is not the profile that I made, but a part of it that the Kemper estimates to be the cab part of the profile. The result is to me completely unpredictable (and most likely irrelevant in our analysis)


    So, enjoy the extremely boring clips :P

  • Loading a profile as a cab block

    Quote from lef38

    Simply use the cab of your lowpass profile with any other profile.
    Which frequency did you cut at ?

    It's strange, but I can't find it in there!
    I find the cab for all other rigs (or so it seems, there are approx. a thousand) but the one I created...?
    Anyway, lowpass at 20KhZ. I am experimenting something to remove some aliasing effect that comes up bypassing the cab sims.

  • Why are The Amp Factory's the best profiles out there?

    Quote from Der_JD

    Absolutely. That is normal for high gain recording.


    My point is this- it seems to me that commercial profiles often come in one of 2 flavors. The first I would classify as going for a more "amp in the room" sound. They sound stellar right out of the box and have an immediate "wow" factor for solo playing. I'd put TAF's profiles in this category.


    The other flavor is what I would call "mix ready" profiles, which is what most of the current high gain profile sellers seem to be offering. These profiles were captured using equipment and micing techniques that aim for a tone that works well for recording with minimal tweaking. Often, a reference tone from another recording is used and the creator of the profile experiments with micing to try to come close to the reference. These profiles often don't sound great on their own (actually, sometimes they're very harsh) but put into a mix (especially with multiple tracks) they come to life.

    I love this classification, I second it entirely! ;)

  • Why are The Amp Factory's the best profiles out there?

    Quote from Der_JD

    IMO, the main reason why TAF's profiles are so popular (talking about clean through medium gain) is that they sound so good out of the box played solo. I think when most people audition profiles, they don't immediately do it in the context of a recorded mix or live setting. That may come later, but initially they simply plug in and let it rip. TAF's profiles, to my ears, sound the most like a real amp sitting next to you. Most do not sound tweaked for recording or live use.


    When I'm just sitting at home practicing or jamming along to tunes, I've yet to find profiles I like more than TAF's. For recording...that's another story. I find that TAF profiles for cleans and low gain generally work fine for recording as is, but for medium to high gain they need a fair amount of tweaking (usually cutting lows and low mids and boosting highs/high mids).

    But that's fairly normal for high gain guitars, isn't it?
    When I play by myself I want the full body, but in the mix I gotta tame low frequencies if I want bass and kick drum to be heard. Distorted guitars are very frequency-greedy :)

  • The Aliasing Problem

    Quote from paults

    At gigs, I go as high as the 24th fret high E. The Kemper sounds just like the amp I profiled, all over the fretboard. I don't claim to have the same kind of ears as the producers who are using the Kemper for major label projects, but they are getting results they like with it, too.


    I agree the clips (especially the second one) have non-musical distortion artifacts in them. But, there is enough input noise to be amplified and distorted, and the second clip has the treble boosted too high to be a practical tone for a mix.


    A non-musical result can be achieved with distortion and a lot of high end with a tube amp, too. Or, just plug you tube amp into a full range PA speaker or monitor, and crank up the gain.

    Do you go to a guitar cab or PA? Cause in the second case the aliasing it's admittedly very hard to hear.
    The input noise is really not a factor, and as I wrote before by plugging in from the front of the unit I solved the hum problem but not the aliasing one (which in fact was even clearer as not masked by the hum)
    Too much treble: see below

    Quote from nightlight

    Can you provide a clip without the hum in the background? Seems to me like this is a case of the excessive brutalz resulting in digital pandemonium. Also, what firmware version are you using?

    I hope I can provide a new one hum-free later today.
    Firmware is 2.4.2, completely up to date.


    Regarding treble and excessive brutalz:
    a) that's not really a good point, right? This profile are made from amps and sound settings that people actually use, and sound good in the real thing. I am sure that it is in the interest of everybody to be able to capture also those sounds. After all, saying that I shouldn't use that much treble is a bit like saying "hey, maybe you should play country instead of metal, it will be all better" :D
    b) I picked that profile particularly because it was (out of those I tried) the most affected (aliasing can be heard for over the highest octave), to make a point. For myself I would use less extreme ones, but it is audible also there.

  • First profile

    Quote from nightlight

    Good for you, Laimon. I suggest you try profiling the amp multiple times. Am sure you'll be able to nail that tone spot on with a bit of effort!

    I will certainly do that, even if only for the fun :D
    In fact the first attempt was already superremarkable, I did extensive refinement (maybe 10 minutes of noodling around, soloing, chords, harmonics, whatever came to mind!) and the only complain I have...well, it's being discussed in another thread and working on the solution, hopefully :)

  • The Aliasing Problem

    Quote from Quitty

    I'm sorry, i was terribly unclear.


    It's often difficult to differentiate aliasing errors from some clipping artifacts.
    Aliasing is purely digital and lower in frequency than the fundamental. Clipping artifacts vary, but cover the range of aliases as well.
    So you are correct, i'm just not sure we're hearing proper aliasing, just something that sounds like aliasing noise.

    No problem, I just wondered if there existed some analog phenomenon somehow referred to as analog aliasing.
    What you say is correct, it might be something else, sure. All points lead to aliasing for now, though: first, because I heard it several times in the past and it was really alike, second because the higher the note played, the more prominent the effect (in line with the fact that harmonics must surpass the range of proerly sampled frequencies).
    Anyway, later today I will provide all infos to Kemper and also try to create cab profile out of a lowpass filter, and keep you posted on the result.
    I am just surpised that no one is being able to reproduce this in their own setup?

  • The Aliasing Problem

    Quote from Quitty

    The rear input is noisier. It's acknowledged by Kemper, don't use it unless you have to.


    By the way, just to be clear - this is aliasing, but really not necessarily digital. Aliasing should exist on your tube preamp as well if you compress the signal hard enough.
    Normally, the cab cuts out most of that, but i've never compared the Kemper's no-cab out with a proper preamp - i would imagine the Profiler is capable of producing much more range.
    Poweramp and cab is *not* the way to test a studio unit, generally speaking.

    Uhm? To me aliasing only make sense in a digital context, because it's an erroneous sample interpolation of frequencies higher than half your sampling rate; hence, no sampling, no aliasing.
    How can it occur in an analog setting?

    Quote from Trazan

    I hear that aliasing in your clip. I can not reproduce it on my Kemper though. Tried it on 3 of my high gain sounds, cab sim off, no aliasing.

    Have you tried with Keith Merrow's KM-ANDROMEDA profile? I used that one for the clips. (with that one I get aliasing easily already on the 12 fret of the G string, absurd!)
    Of course it depends also on the guitar, I might well imagine pickups and buzzing from low action generates a lot of that.


    BTW: I already received a reply for my ticket, they asked more info (which I am gonna provide later at home), and said:


    To shape the frequency range for the monitor output you can use the dedicated Monitor EQ that you can find in the output menu.
    You could also try to profile a static lowpass filter and use the resulting cabinet in your rigs if you want to cut high frequencies before going from the Monitor out to your poweramp.



    I have tried the first, but I didn't find the EQ fine-grained enough for this.
    On the other hand, I would definitely try the second option, which seems the best one to me. I didn't see options for profiling something as a cabinet, though?