Recently, I have been getting hard crashes on the Kemper, either when switching Rigs in Performance mode, or, more frequently, when engaging the Looper to start or stop a loop.
‘Hard crashes’ means that any sound from the Kemper stops, the user interface becomes completely unresponsive, no buttons on the Kemper or Remote have any effect, the only way to recover is to switch off the Kemper, and switch it on again.
I have seen that after switching the Kemper back on, it sometimes confuses Rigs in a Performance - so you have to reboot a second time to get it to work correctly.
The crashes occur seemingly at random, in different Rigs, different Performances, when hitting different buttons on the Kemper Remote.
The crashes occur on average maybe once per hour at minimum - no way to get through a rehearsal or a gig crash free at this stage.
I have been in touch with Kemper support, after much back and forth, they were able to reproduce the crashes.
Here’s what I learned from the interaction with Kemper support:
- there is no fix for the crashes
- if you use ‘DSP hungry effects’ - like one mono Transpose, one mono Delay, two stereo Delays in a Rig, and engage the Looper, you can get the described crashes , due to 'DSP overload'
- the crashes are expected behaviour, Kemper support does not acknowledge that DSP overload should not result in a hard crash (if you get DSP overload in a DAW, you do not have to reboot the computer because if freezes completely. In ideal condidions, depending on the CPU spike, you may get uninterrupted playback, and not even notice the temporary overload.)
- Kemper support blames end users for these crashes
- Kemper support acknowledges that their Looper is not functional, and recommends to purchase a looper pedal if you want to loop and use ‘DSP hungry’ effects in your rigs at the same time
- Kemper support is aware, and could not care less, that, due to the mono-send, stereo-return nature of the external effects insert, the only way to loop in stereo (like the built in looper) is to connect from the Main Out to the Looper pedal - which means, Balanced Out is not an option anymore; Output Level has to be adjusted for the requirements of the looper pedal, not the audio interface or FOH board (which compromises correct gain staging); both Monitor Out and SPDIF out become unusable because they don’t contain the looped signal; and there is one additional A/D/A conversion in the chain, which does not help audio quality.
- it is the responsibility of the end user to determine how much DSP an effect in each slot in the Kemper uses, and adjust DSP consumption accordingly, so that no crashes occur
When I am supposed to estimate how much DSP an effect uses to avoid crashes, I do have follow up questions on how exactly to do that.
Kemper support has (repeatedly) refused to answer any of the following questions (quotes from email correspondence):
- how am I supposed to determine which effect uses how much DSP?
- please kindly provide a list of all the effects the Kemper uses, with reference to how much DSP they use individually
- please also provide a contextual reference as to how much of summed DSP causes DSP overload - e.g. 4 slots with Green Scream etc.
- why are you blaming end users for crashes?
- will you remove the ‘Looper’ functionality from your advertisements and feature lists of the Kemper Remote, as it does not work?
- please kindly explain why I also got crashes when the Looper was not in use, and why the same Performance failed once when switching Rigs after working reliably for months - how can I determine that the root cause is actually DSP overload in a case like this?
- why does DSP overload cause a hard crash with no sound, instead of failing gracefully, like on every modern computer?
- why are your developers not willing to look into the reason why DSP overload causes a hard crash?
- will you re-imburse me for the purchase of an external looper, as the advertised functionality in Remote is not available?
- you use the term ‘workaround’ when suggesting to use ‘less DSP hungry effects’. Will there actually be a solution?
My experience with Kemper support has been awful. At one stage, the support person had completely forgotten a week’s worth of email exchange (and the fact that he had reproduced the issue), and suggested a troubleshooting step that I had performed 2 or 3 times before, to determine if it’s a hardware fault.
When, after that, I sent him a mail with our complete correspondence pasted in for his convenience, he still could not be bothered to actually read through it and answer questions.
After suggesting countless times to have the crashes looked into by developers, and being ignored each time, here’s the last response from Kemper support:
“They will consider implementing a routine that will prevent the looper from being used in such a scenario in a future version of the operating system.”
So the Kemper developers’ approach to avoid crashes from DSP overload is not to investigate why DSP overload causes a hard crash (and fix the code), but to work around it by limiting resources that can cause DSP overload. And maybe not even that - they consider it.
Two ways to view the Kemper are:
- as a convenient, almost there, 1:1 replacement for a tube amp
- as a creative tool with virtually unlimited potential, that can by far surpass the sound possibilities of a conventional ‘tube amp & pedal board’ set up
I’ve always been a strong advocate of the second point of view.
Changing a musician’s process from ‘how can I use this tool to create the most amazing sounds I can imagine’ to ‘how can I babysit this tool, using a bunch of unpredictable, arbitrary, fear-based parameters, so it does not crash’ means completely breaking the creative potential of a mindblowingly brilliant product.
TL;DR:
- we end users take the blame when the Kemper crashes
- Kemper developers have no interest in fixing crashes that occur due to DSP overload
- Looper is not available when you purchase a Kemper Remote and are planning to use internal effects in the Kemper indiscriminately - if you want to use a Looper with effected rigs, Kemper support recommends you buy a looper pedal
