Posts by heldal

    The Remote works on a different voltage when fed from the PROFILER. Seperate wires are used for those two voltages. Don't feed 48 volts into the wrong wires since it could damage the Remote.

    Can the power from the Profiler cause damage to an ethernet switch or HUB?

    Why deviate from the PoE/PoE+/PoE++ standards designed to make alle ethernet-devices interoperable?

    Blueamps Spark (2x10" active stereo cab). Does anything from bedroom practise to band-practise and big stages. Blueamps specialised in FRFR-cabs years ago when there were few alternatives other than Atomic CLR and Friedmans FRFR-monitor. Today I may have chosen the Kemper Power Kabinet, but I am still happy with my Spark.

    I've been using my L6 G90 with my KPA and Sennheiser IEM for years. The G90 is operating on 2.4GHz, but I have stayed on the old transmitter firmware which produce a stronger signal. Possibly too strong as it renders any 2.4G WiFi nearby useless. No dropouts unless I go too far from the receiver or behind a brick wall. The transmitter for the G90 and G50 should be the same (TBP-12), but I can't remember if the reduction of transmitter signal strength was only a firmware update, or wether later TBP-12 transmitters also had their hardware altered.

    Was playing around with a lap-steel studying a few youtube-lessons when I noticed that my open-d-tuning was way off from the video, it was consistent across several videos. About 1,5 semitones sharp when I had used the tuner on the KPA. Then after about half an hour the audio starts crackling. Switching rigs, and back and forth between modes etc changes nothing. There are no errors reported by the KPA. After reboot everything is back to normal, at least for now. The crackling was like there is a an internal sync problem, and one that also throws the tuner off. Scary. It would be a very unpleasant experience on stage. Ticket filed.

    This is exactly the problem for Kemper; everyone wants something different.


    I'd settle for no screen with just a volume control and Kemper logo on the front, which would bring down production costs. It could still have all the ins and outs on the back. That way we could get it into a 1u rack and control from a phone or computer.

    I think a modular design could cater for many different wishes. It would also make it possible to change configuration along the way without replacing the entire unit. For rack-mount there could be a 1U main unit with a minimal display, I/O and a few knobs, then a 1U display-unit with a pop-out-fold-up larger touchscreen for editing and a separate 1U poweramp. The main unit would be the only mandatory component, everything else optional. I.e drop the screen-module if you use an external editor. Drop the power-amp if you have powered monitoring-gear.


    For me however the biggest reason to upgrade at this point would be more powerful hardware to enable near zero-latency switching (at least) within a performance and eliminate some of the sluggishness in the UI. Boot should be done in 5 sec max.

    Let the engineers take their time. The last thing I want is to see performance and/or stability compromised because an unfinished feature is added too soon. My experience is that at-times for switching slots and performances are increasing, and the UI getting slower. Both indications that the current hardware may be stretched to its limits. New features may thus require quite a bit of optimisation of other code to make "room". That is no walk in the park.

    When I open effects presets for the first time after boot there are two problems:

    1. There is a delay because the list/menu has to be initialised. I would suggest to perform this initialization during boot because it doesn't add significantly to the already tedious boot process.
    2. When initialised the category/type/preset-menus are out of sync. I you for example access the menu from the reverb-button it will on the first turn of the browse-button jump to something completely irrelevant such as distortion. Exit effects and reopen, and everything is ok. The state of the menu (type/category) when initially opened should reflect the current effect in the slot the menu is accessed from, and the preset-pointer should be at the header of the given category-type. Turning the browse-knob may when turned counter-clockwise go to the last preset in the previous category/type, but should when turned clockwise never jump to a completely different location in the category/type/preset-tree.

    These things only happens the first time effects are accessed after boot, but it is still a recurring pain every time I use the KPA. If 1 is fixed then 2 may be fixed too ... I don't know. If I were a KPA-developer I would consider this a bug. It seems to me like an issue with initialisation of pointers to a structure of information and should not be too hard to fix.

    I should probably post a follow-up on this after working it out with support. It may be of interest to others with similar problems:


    Being out of warranty long ago I ended up taking the KPA apart and found that the small circuitboard holding the main CPU was not seated properly in its socket. It had come partially loose on one side. I took everything apart, cleaned oxidation off connectors, removed all dust and put it back together. I have not had any problems since.


    Btw; The job was simple, but it does require an anti-static workplace and the right tools for the job. Static discharge may fry components inside.

    You should never rely on the soundguy to boost your volume for solos. That won't work unless you have an audio-engineer that is practically a member of the band. I boost output for solos either with morphing to a raised rig volume or switching to a louder separate rig. For small gigs with no soundguy I do the mixing myself from the stage and have become used to listen to the same mix that go to FOH. Ideally, with a soundguy I also prefer to have the same relative mix, but adding a couple dB extra of my own guitar and voice to my inears by setting up a post-fader tap of the main mix with a little extra for the channeks that matters. I don't like the added latency of feeding monitoring back through my KPA . If I have no control of the monitoring mix myself, then I'd rather have a FR-cabinet behind me or a dedicated wedge for guitar in front of me.

    I finally got around to open the unit and have a look. Being 10 years old it's warranty expired years ago. I've done lots of curcuit-board and VLSI-design over the years so I have an appropriate workshop for the job. Most important is to make sure that yourself, the work-surface and all tools are properly grounded so you don't accidentally fry circuits with static electricity.


    What I found was that the small CPU-circuitboard was not properly seated in its socket. I find it strange to cause problems on and off over time like I have experienced, but feedback from support suggest otherwise. A 10 year old unit is likely to develop issues with oxidation on connectors, so I took everything apart, cleaned and put it back together. And I took the opportunity to replace the old battery.


    The unit has worked fine for the last couple weeks. Fingers crossed it will be back to normal reliability for another few years.

    My 2012 KPA-head has developed a problem in the last year. For no apparent reason the entire front-panel goes blank, except for LCD-backlight. Knobs and buttons are non-responsive. Have to pull the plug to reboot.


    The unit keeps processing audio and switches performance, slots and effects via the remote. It can also be controlled from RM.


    Sometimes it happens within 5 minutes after power-on, but usually the unit has to be left running for a few hours first.


    Each time I upgrade firmware the problem goes away for a few weeks, or even months. Overwriting impliers refreshing NVRAM content so this may suggest some sort of NVRAM-failure or possibly battery issue. My use of the KPA varies from daily to weekly so it may also be a battery?


    What do you think? Faulty NVRAM, battery or failing front-panel circuit?

    I have one that is equally old which also has started acting up, but a little different. Mine doesn't shut down, it is just the front-panel that goes inactive every now and then. There is LCD-backlight, but nothing else is working. The LCD is blank. I can't even shut it off with the chickenhead knob. It can be controlled with the remote and is producing sound, but I have to pull the plug to turn the KPA-head off.


    However, I've found that the problem disappear for a couple months if I upgrade the firmware or reload the release that I am on. Could it be failing NVRAM causing corruption of code that is happening on older units? I'm just speculating, but that could cause all sorts of random problems. Have you tried to upgrade or reload firmware?

    Assume you mean "main", not "mail" there :)


    This explains your problem. You are sending the same signal to the PA as the one you are sending to your amp and 4x12 guitar-cab. That means that the effect your amp and cab has on the sound do not apply to the PA.


    The better way to do this is to :

    1. use monitor-out into your amp+cab, and main-out to into the PA.
    2. Set cab emulation off for the monitor-outputs in output settings. Also set monitor to stereo and connect direct-out to your amp for a stereo
    3. Disconnect main-outs from the master volume in output-settings to enable adjustment of monitor volume independent from what you send to the PA. At the same time you can also enable the 10dBm output reduction for the main outputs. That will stop most audio-techs from complaining that your KPA's outputs are too loud.
    4. Re-adjust the rigs you use on the KPA so that they again sound good through the 4x12. (Now without cab-emulation in the KPA)
    5. If the emulated cab in each rig now has characteristics similar to your physical cab, then you should achieve a very similar sound through the PA (which still has cab-emulation active).


    With rigs in the KPA that use an emulated cab very different from your physical cab then you may struggle to make the PA sound the same. One amp into two different cabs can be almost like two different amps. The cab colors the sound a lot. This is why most people seem to prefer to use a neutral monitoring solution and keep cab-emulation on for both monitor and main outputs.

    Does your guitar sound OK through the PA-speakers? If it does, then the problem is with the mix in the X32. If not, then is CAB-emulation on in the RIG(s) you use on the KPA? Assuming you use a powered KPA to feed your 4x12 I suspect that you are missing CAB-emulation for the signal going to the PA. You wouldn't be the first not to read the manual and/or not explore the output options and still get great sound through a traditional cab by turning off cab-emulation in the stack, only to discover that the signal going to the PA sounds bad. The correct way to do things when using a powered KPA (or unpowered KPA some external amp) into a cab for monitoring is to keep cab-emulation on in the stack for each rig but turn it off globally for monitoring in the output settings. That keeps cab-emulation on for the main-outputs. The signal going to the power-amp in a powered KPA is the same signal as the one going to the monitor outputs. If the emulated cab in each rig you use has characteristics similar to your physical cab then you may get similar sound in the PA (and your in-ears) to what you hear from your cab.

    How about a browser-based application to access the Kemper over the network? It would automatically be usable by any system running a modern web browser. Linux! Android!

    We actually had that in a Beta prior to the launch of the Kemper Remote. It was a web-app emulating the remote with display and switches. At that time the KPA would happily attach to your house-network grabbing an ip-address from the local DHCP-server. The problem we have at the hardware-level is that the Kemper Remote, if you use that, require power over ethernet so you will net a PoE-capable switch when the Remote can not connect directly to the KPA. It is some time since I last tried to hook my KPA up to my network so I don't know how well it can coexist with other gear today. The core of the unit is network capable so there's at least opportunities for interaction between the KPA and RM as well as for example audio over ethernet (DANTE/AVB).

    Most likely you have some corrupt files which happens from time to time using databases. Deleting the corrupt file is all that is needed. Doing a factory reset can work wonders, but I would check with Kemper Support before doing this. Make sure you backup your important files first. It is nearly impossible for computer components to fail that do not have moveable parts like a IDE hard drive, switch, dial, etc. You have to take a hammer or put them in a fire to break them. I have an Atari 2600 that works like when it was purchased in the 80's.

    Database corruption is not something that just happens every now and then in a database, or any storage for that matter. It is always caused by some kind of failure in software or hardware. The KPA performs some limited consistency-checks during upgrades, but there is a need for more. Especially as the hardware is getting older. There should be a consistency-check available in the menus that checks both firmware and data. My KPA had a rather serious issue with the front-panel being seemingly disconnected at random. LCD backlight was the only sign of life although the unit was working fine with the remote. Even the power/mode-switch wasn't working so the only way to regain control was to pull the plug. The problem disappeared after upgrading to the current production firmware. Nobody else had reported similar symptoms, which make me suspect a glitch in the NVRAM where the firmware is stored. I had been running the same firmware for some time without problems when the issue first appeared so it wasn't simply a bug in that particular firmware. A simple checksum validation of NVRAM-content could have pinpointed the problem immediately.


    My Kemper's 10th anniversary is coming up so I'm also starting to be concerned about maintenance. Warranty ended years ago and shipping such old gear half way around the globe for expensive repairs isn't reasonable IMHO. Maybe the community should create and maintain a list of things to do and how, what tools are required, possibly with instruction-videos etc. The most obvious things being tasks such as cleaning the internals and replacing circuit-board batteries.