Sudden major issues with my long time owned PowerRack

  • Hello,


    First time posting on the forums, as my PowerRack has worked flawlessly since I got her in 2017....until today.

    A few days ago I went out of town and powered everything down since I was going to be gone. Then last night when I returned and there was a new guitar waiting for me,

    so I eagerly powered up my Kemper to start shredding, and to my dismay there was a horrible static, white noise and worse sound coming from my cabinet and no signal from the guitar.

    I switched it to the tuner and it worked fine, so I know it wasn't an issue with the guitar. After switching to various other speaker cables, the problem remained. After a lengthy process of elimination, I have determined that it seems to be related to the Speaker Output. I can hear the signal through my powered monitors (I have the Kemper going to my audio interface) but no signal from my 4x12 cab. This is the same cab I've been using since day one of owning the Profiler. Only loud, horrible hiss and noise, with clicks and pops that seem to get worse and worse the longer it stays on. I updated to the current OS build, but it didn't change anything.


    Again, it should be noted that when I powered everything down on Thursday morning, everything was working as it should. The next time I turned it on, which was Saturday night, this issue presented itself. I'm a little concerned that something serious is wrong with it.


    Any help or tips are appreciated.

    I'll record a little video of what its doing and upload to YouTube and post the link to show exactly what its doing.


    Thanks in advance!

  • Sorry to hear that. I hope it's something simple to fix. Worst case scenario you can sell it as an unpowered one and buy a new powered one since the power amp is probably the culprit.

  • This sounds like a worse case of the issue I posted yesterday. I think I helped it today by unlinking the volume links and cranking the power amp boost (I was running very low compared to what I could see people using online).


    I have a ticket submitted & I'll let you know if any advice looks helpful for you.

  • I've uploaded a short video of the symptoms. My cell phone video doesn't properly show just how abrasive and loud the hiss and high pitched squeal is that emanates from the cab when powered on. Nothing I do changes this. I've switched cables, tested the cab with other heads to ensure it wasn't an issue of the cab, nothing I can do helps.


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  • I dont have a powered Kemper but something you said has me thinking. Especially this time of year (cold).


    If you left for a few days and turned down your furnace, the humidity in the house may have risen a lot. This may add some oxidation on connections.


    Not sure how the power amp is connected internally but hopefully it is just a bad connection. And not something was damp when you powered it up and popped something.


    Just wishful thinking. We will all pray for you :)

  • I left but the house was still occupied, meaning there were no changes in terms of the interior climate of the house while I was gone.

    I should also note that the PowerRack is plugged into a Furman Power Conditioner.

  • Check if the issue is really limited to the SPEAKER OUTPUT, which is the output of the built in power amp. The signal of the MONITOR OUTPUT is feeding the input of this power amp internally. What if you plug your headphones or one of your powered monitors into the MONITOR OUT? Is that signal ok? In that case we have to conclude a defect of the power amp. Sorry, for the bad news! Please open a support ticket then to initiate repair.

  • Check if the issue is really limited to the SPEAKER OUTPUT, which is the output of the built in power amp. The signal of the MONITOR OUTPUT is feeding the input of this power amp internally. What if you plug your headphones or one of your powered monitors into the MONITOR OUT? Is that signal ok? In that case we have to conclude a defect of the power amp. Sorry, for the bad news! Please open a support ticket then to initiate repair.

    Monitor Output works fine, because I have it going to one of the channel inputs of my Audio Interface, which is then going to my powered monitors and the signal works fine. In fact if you watch the video that's why you can hear the guitar signal when I strum the guitar. It's my conclusion that it seems to be just Speaker Out that is malfunctioning. I'll look into the support ticket.

  • It appears, the power amp is defective. Too bad!


    By the way, I don't understand your concept of driving a 4*12 from the SPEAKER OUT and powered monitors from your MONITOR OUTPUT at the same time. Running a guitar cab from the SPEAKER OUT requires Monitor Cab. Off being activated, Running full-range monitors from the MONTOR OUT requires the opposite.

  • It appears, the power amp is defective. Too bad!


    By the way, I don't understand your concept of driving a 4*12 from the SPEAKER OUT and powered monitors from your MONITOR OUTPUT at the same time. Running a guitar cab from the SPEAKER OUT requires Monitor Cab. Off being activated, Running full-range monitors from the MONTOR OUT requires the opposite.

    Monitor Out is going to channel one on my Presonus interface so that when I am recording in my DAW, the signal is direct from the Profiler when recording. The Profiler isn't hooked up exclusively to powered monitors for the sake of being connected to powered monitors. I could be doing it wrong, but this is the way I've successfully recorded with it for years now.


    It could be that my Kemper is just mad at me for relegating it to a backup amp since I've recently switched back to a traditional setup of a tube amp (6505+) and Mesa cab + SM57. /shrug

  • There is still this fundamental conflict, that you are either running a cab simulation through a physical cab (Monitor Cab. Off not activated) or recording a signal without cabinet in the signal chain (Monitor Cab. Off activated). This is one of the basic concepts of the PROFILER described in all manuals.


    The PROFILER offers multiple outputs to separate the sounds for those applications. Recording via MAIN OUTPUT is the recommendation.

  • TBH this stuff is quite confusing to me and my knowledge of it is rudimentary at best. I don't understand how I'm supposed to hook my Kemper directly to my audio interface via Main Output since I see only left and right 1/4" jacks and XLR outputs. I just want to be able to have the Kemper hooked to my 4x12 cab as well as have whatever Rig I'm currently playing go directly into Input 1 on my interface and therefore my DAW. I've been doing it my way for a number of years with great results but if there is a more appropriate way, I'll do it if it can be described in a way that I'll understand. Also, I don't care one bit about having raw unprocessed signal going to my DAW because I don't use software amp sim plug ins. Any help is appreciated.

  • Use one of the Main outputs, set to Master Mono to feed your DAW so it contains the profiled speaker that won't be in the Monitor or Speaker feed if you have Monitor Cab off.


    If you don't have Monitor Cab off then your speaker cab is getting fed a signal with a speaker already in the sound, so the DAW will be correct, but the speaker might sound less articulate.

  • I have to agree with the rest, if you're using a cab connected to the power amp at the same time as recording, then use the main outputs to connect to the audio interface, either 1/4" or xlr.


    How about did you check:


    * Try a different speaker cable?


    * In the output menu, advance all the way to page 9 using the page buttons. Is the power amp box checked as on?

    With mine you can hear some connection clicking inside the Kemper when you check or uncheck the 'power amp on' box.

  • Yes, I have tried several different speaker cables, all with the same result.

    And yes, I do hear clicking inside the Kemper when I check and uncheck the "Power Amp On" box.

  • Use one of the Main outputs, set to Master Mono to feed your DAW so it contains the profiled speaker that won't be in the Monitor or Speaker feed if you have Monitor Cab off.


    If you don't have Monitor Cab off then your speaker cab is getting fed a signal with a speaker already in the sound, so the DAW will be correct, but the speaker might sound less articulate.

    I made this changes. Thank you! This is what happens when you dont read the user manual very well and haven't opened it since 2017. HA!


    Meanwhile, the primary issue with the power amp is still the same. :/