Posts by DigitalBliss

    Hi All,

    I'm using the Alternate Input and Return jacks on the back of the toaster (mine has no power amp) as inputs for stereo backing tracks I jam along to. I have two studio monitors connected to the main xlr outputs and an active FRFR monitor connected to the monitor output (I use either the mains or the monitor, but not at the same time). When I use the studio monitors on the main outs, I have the Aux In >Main setting set to 10.0 (Output section page 7/8), and I adjust my rig volume to a level that seems to mix well with the backing track. So far so good. My question is, when I use the single FRFR monitor, and turn off the mains, I have to dial down the Aux In >Monitor setting to 3.1 to match the same relative volume of my guitar (I leave the rig volume the same). Does anyone know why that is? Why I have to attenuate the aux level so much when using the monitor output? It makes me think I have another setting somewhere else that is either boosting the aux level into the monitor signal path, or is attenuating the aux into the mains signal path.


    @nejo_hh, that's a great writeup. Thank you for taking the time to post it. What tool are you using to do the math? Matlab, Octave, other? and what platform are you on, Windows? Mac? other? I did a lot of this at work (I'm a retired engineer), but looking for a tool to use at home. Thanks again, and if this wanders too far from the original intent of the post, I can take this off the board and chat via private conversation if you prefer.

    One thing you can try is take the JBLs off the stands. When a speaker is on a stand it's sort of "free-radiating" and the bass frequencies are spread out in all directions. You can really boost the bass by either placing them on the floor, or against a wall, or to get even more bass boost, try a corner between a wall and the floor. See this link for an explanation of why
    Configure your PA
    If you use the room to your advantage, you probably wont have to max the bass on the Kemper, and you might get by with the smaller JBLs if you aren't driving them so hard. Experiment with placement and see if that helps.

    Hi Rich,
    I tend to agree with your assessment that the Kemper sounds better loud, but I don't think it's because of your speakers or headphones, I think it's because whoever made the profile you were playing was probably playing it loud. As the others have said, If you like a profile loud, you will probably think it sucks at an apartment room level (and the opposite is true also). You can tweak them to sound better at bedroom levels, but it will take you a while working with the Kemper to build up those skills. I've had mine for 4 years and I still haven't figured out a formula to convert a profile which sounds great at gig level to one that sounds great at talking level. I've actually tried keeping two sets my favorite profiles, but I haven't been very successful because my low volume home practice level is never the same. Sometimes low (for me) means talking level, and other time it means playing at home alone but cranked up just enough that neighbors don't complain. So my low volume profiles are really all over the map.

    I'll tell you what I did (which might not be too popular on the forum) but I bought a Yamaha THR10c for my bedroom, and I keep the Kemper set up for mostly band practice levels. Again, I think the reason the Yamaha sounds so great at bedroom levels, is because it simply cant get very loud, so the designers tailored the tone to be really pleasant at the quieter volume. I honestly think it sounds better than most of my tweaked low volume Kemper profiles . Now to be fair, I haven't sat the two units down next to each other and tried to match them one to one, but I have spent weeks chasing a tone I wanted on my Kemper at a low volume, and finally settled for something close but not great. When I bought the Yammy, I was able to dial a similar tone in in in a few minutes. It's just made to sound good at really low levels. Like I say, I probably could get the Kemper to eventually sound great at low volume too, but it would take a considerable amount of time to tweak my 50 or so favorite profiles, and I would have to do it in a controlled environment (always at the same low volume) and honestly, I would rather just plug in and play.

    One of these days I might try to build a reverse Fletcher Munson transform using the studio EQ for one of the curves that best represents the difference between what I consider loud and quiet playing levels. Unfortunately the Kemper has no graphical monitor of EQ, so I' would have to monitor in a DAW, but it would be a fun experiment. Maybe a good project for when I retire from my day job. :-)

    Ah if it were just that simple. Every guitar I have has noiseless pickups. I have shielded every one. I have replaced pickups and wiring in most. I have a drawer full of SCs. I even have a few humbuckers in the drawer where the coils were not balanced closely enough. I have searched for the most noise free profiles. I have been struggling with this for years and years. I stayed at my father-in-laws house for about six months a few years back, and it was like heaven compared to my house. There was a little noise, and you could do the trick like point your guitar in the right direction to minimize it to nearly zero, but when I cam back home I almost cried it's that bad.

    Yes, same for me. Since this discussion reminded me of my sorry state, I did a little more research. As it turns out, the wiring and devices in your house can create two types of effects. They can induce electric fields and magnetic fields. Guitar pickups are sensitive to magnetic field variations, and are much less sensitive to electric field variations. This is important because you can get big magnetic fields which can propagate many feet or even meters if your building wiring has stray return paths. If the hot wire and the return wires are right next to each other (as they should be) and current is flowing, the two magnetic fields will nearly cancel each other out and you will get a small combined magnetic field that fade away to nearly zero in about a foot or about 30 cm. If the wiring is incorrect and current is flowing (even small currents like a lamp), and the current finds a return paths through a different wire or even some metal pipe, you can get large magnetic fields which don't cancel and can be detected many feet or even meters away. So I think an electrician having a look for possible wiring errors (and I understand these are common mistakes) would be wise. I myself am planning to retire from my day job in a few months, so I'll probably call someone out then when I have more time to attack this.

    I am in the same boat. Real bad case of EMI and I have shielded all of my guitars with only minor improvement. I built a portable EMI sniffer (battery brick -> high gain 40db solid state amp -> single coil pup, and small speaker) and have mapped out the worst areas of my house. They are all near electrical outlets and wire runs in walls and under the floor. I have an old house and some outlets are not grounded (they only have the old 2 prong sockets). I have not been able to identify any particular appliance that might be causing the noise, but I haven't ruled that out yet . I think I'm going to put my sniffer in a noisy location and have my wife cut power at the fuse box to various rooms and see if I can narrow the search. If I cant find a particular device to turn off that will help quell the noise, I am planning on calling an electrician out and show him my problem to see what he can do.

    Oh, and I should add that I've had my Kemper and guitars out of the house and they always sound way better just about anywhere I go. Way less noisy, and then I always come back home and swear at my stupid house when I cant get a good mojo going because of the noise.

    Hi All,
    I was the other bay area tester. It was great of OP to set up all the gear and let me have the opportunity to try these all out. I only played with them for a half hour or so, but I agree with everything the OP said.

    I will add that although I thought the Atomic sounded the best to me as well (it was a little crisper and punchy-er on the high end than the Yamaha), but I would probably still go with the DXR10 over it. The DXR footprint is just so much nicer, and in my opinion the price difference was not worth the small edge out in tone. I will also add that I thought the Yamy had the most even dispersion pattern of the bunch. OP had it in the wedge position on the ground and I kid you not, it sounded the same even up to 45 deg off to either side, and only when you got way off to the sides did the treble fall off a little. Either the Matrix or the Gemini had a very narrow sound stage and rolled off quickly starting about 20 deg off axis (OP might remember which one this was). Also the Gemini was quite large (if size if a discriminator for anyone) 52 lbs, 2 feet across and about 20 inches tall. Also both the Gemini and Matrix were a little hissy while the Atomic and DXR were very quiet when the guitar was muted. The tiny hiss was insignificant at loud volume though, and might only bother you if you tried to play them in a quieter environment. Thanks again OP for the opportunity to try all of these.

    Welcome Angus,
    You only really need the UR22 to record. So if you record frequently, you can use the UR22 as the mixer by bringing the Kemper outs into the UR22 inputs. But then every time you play you have to power up the UR22 (and maybe your computer depending on where you monitor). If you record infrequently, you can just bring any backing track source into the Kemper and use the Kemper as the mixer using the Alternative Input and Return on the back. You need a special cable for this, but there are directions in the manual, and pictures on this forum. Just google Kemper Alternative MP3. In this case you just plug the headphones into the Kemper and you're good to go. You can even practice without the computer if your just doing scales and such.

    @ PaulReedSmith
    The noise you hear is electromagnetic interference. This can come from lots of sources around you (PCs, fluorescent lights, switching power supplies, motors, etc.) It is not coming into your Kemper through the power cable (as evidence by the fact that some orientations of your guitar produce almost no noise) Rather it is coming into your guitar pickups from a radiating source. Your pickups detect this noise and send it out your guitar cable to be amplified by the Kemper along with the good signal produced by your stings. The more the amplification (gain) the more you hear it. Especially at high gain levels when lots of compression is occurring. At high gain, your guitar signal and noise are both amplified by the same gain, but the guitar signal being stronger begins soft clipping (distorting) while the noise just gets louder. So it sounds relatively louder (compared to your music) than it does at lower gain. Single coils pickups are the most susceptible, but even guitars with humbuckers can pick this noise up especially if there is no shielding in the electronics cavities where the signal wires are just an unshielded pair. I have a PRS Core Mira and was disappointed to see no shielding in the cavities. I shielded it myself to make it more quiet. Why an expensive guitar like this is not shielded amazes me. Of course the ultimate solution is to get away from the source of the offending electromagnetic interference, but in my case I could not identify where it was coming from. I actually took my guitar and a portable amp, and walked all around my house trying to find where it was coming from and could not. So I live with it, but I can minimize it by ensuring that all my guitars and cables are well shielded, and this makes it more tolerable.