KPA froze moments before my gig last night!

    hi everybody. well, it finally happened to me last night. after successfully using my unpowered KPA for the last year and a half, it totally froze up on me minutes before my gig started. just a little background. i control the KPA with a liquid foot 12+ and run it direct into the mixing board for this particular band (we all use in-ear monitors). up until last night, the KPA has always worked perfectly and never given me any problems whatsoever. we were playing at a high end wedding in brooklyn, NY and couldn't really set up until 20 minutes before we were supposed to start playing (the ceremony, cocktail hour, and reception were all in the same room and it was a total mess). we usually have a couple of hours to do a long soundcheck and relax a little.


    once we were able to setup, i noticed that my KPA was taking a lot longer to start than usual. it finally booted up but was stuck on 1 patch. i couldn't change patches via my LF12+ or via the front panel. i was still pretty calm. i tried to power off the KPA but it was frozen and wouldn't even turn off. still fairly calm. i unplugged the unit and plugged it back in. again it took forever to start up. it finally went back to that same patch. i was getting a signal but again i couldn't change patches at all. i then noticed that the screen of the KPA no longer displayed that patch name. it just said "kemper profiler". again, it was frozen and wouldn't power off. i started to freak out! =O again, i unplugged the KPA and tried a different outlet. i thought that the outlet that i had previously tried might have been funky. the same result happened once i plugged into the other outlet. i was in full freakout mode. nothing was working and my kemper kept freezing and was unresponsive. i was lucky enough to restart the KPA once again with the midi pedal unplugged and just did the entire set on one patch.


    luckily, we only had to do 1 set on this particular gig because there was a salsa band and a DJ who were also splitting the night with us. if this band had to do the entire gig it would have been a DISASTER and i could've potentially lost my job with this band (i'm a professional musician and rely on these gigs to make a living). this cannot happen again.


    of course, i set my gear up once i got home and everything was fine. the KPA worked perfectly and i was unable to duplicate what had happened on my gig. could this have happened because of bad power at the venue? i was told that the KPA doesn't need to be run with a power conditioner or a voltage regulator. i don't really know what to do at this point. thanks for reading this post and i'm all ears if anyone has any ideas as to what happened last night.


    thanks!


    jack


    p.s. i was running the latest official released firmware for the KPA (not the latest beta)

    Quote from jabromusic

    i was lucky enough to restart the KPA once again with the midi pedal unplugged and just did the entire set on one patch.

    Bummer. 4 years of gigging with mine and no issues so far.


    So presumably there was NO front panel control with the MIDI pedal unplugged??

    Quote from Gizmo

    Bummer. 4 years of gigging with mine and no issues so far.
    So presumably there was NO front panel control with the MIDI pedal unplugged??

    i'm not sure. by that time we had to start playing and i just had to deal with what was happening. if there was a problem with the midi pedal and the KPA working together i'm guessing that the same thing would've happened once i got home and hooked my rig up

    Couple of thoughts, I'm not sure if these are related to your problem but I thought that I would share them just in case.


    1) One time when I was using a MIDI controller (before I got the Kemper Remote) and I accidentally misaligned the MIDI cable when plugging it into the controller and IIRC it acted like you described. What happened was the MIDI controller had a 7 pin socket because it supported phantom power, I was using a 5 pin cable and somehow had it misaligned when I plugged it in. MIDI connectors do have a key so you shouldn't be able to do that but somehow I did :)


    2) I discovered by accident that if you turn the master volume knob on the KPA while it is booting it won't boot correctly. This makes me wonder if your controller was sending commands to the KPA while it was booting causing it to lock up, I'm not sure if MIDI commands would affect the KPA like turning a knob on the front of the KPA but it might be worth investigating. BTW, I did report this and Kemper support was able to duplicate the issue so I'm sure that they will address it in a future update.

    Quote from timowens

    Couple of thoughts, I'm not sure if these are related to your problem but I thought that I would share them just in case.


    1) One time when I was using a MIDI controller (before I got the Kemper Remote) and I accidentally misaligned the MIDI cable when plugging it into the controller and IIRC it acted like you described. What happened was the MIDI controller had a 7 pin socket because it supported phantom power, I was using a 5 pin cable and somehow had it misaligned when I plugged it in. MIDI connectors do have a key so you shouldn't be able to do that but somehow I did :)


    2) I discovered by accident that if you turn the master volume knob on the KPA while it is booting it won't boot correctly. This makes me wonder if your controller was sending commands to the KPA while it was booting causing it to lock up, I'm not sure if MIDI commands would affect the KPA like turning a knob on the front of the KPA but it might be worth investigating. BTW, I did report this and Kemper support was able to duplicate the issue so I'm sure that they will address it in a future update.

    thanks for your reply tim! it definitely wasn't a misaligned midi cable. in fact, i believe i unplugged the midi cables and plugged them back in at one point and there was no change. the midi pedal was definitely on and connected at startup but i always start my rig up like this and it has never froze up in the past

    Quote from creative360

    Over a stretch of 50 or so gigs, there were a couple of funky moments where the Kemper sort of went into protection mode, rebooting mid-song, due to some overtaxed, subpar electrical outlets. But those were my shows, in a hectic crowded dance party atmosphere. The experience kind of built character, no big deal really. In the scenario you describe, as a service provider, after maybe the second attempt at booting up the KPA, I would've switched to a simple backup like a zoom MS pedal or an amp character pedal. That type of thing can shake you to the core, but night in and night out, most would say, and it's been my experience, that the Kemper is way more reliable than any experience prior, using traditional analog/tube approach. Every time I see a guitarist setting-up a traditional rig, they're always frantically plugging and unplugging pedals seconds before the show, searching for the cause of some random issue. Glad you kept your cool and saved your gig.

    i actually have a sansamp flyrig 5 which i will ALWAYS have in my car from here on out. this was a very nerve racking experience and could have been a total disaster if the circumstances were different. it also could've jeopardized my job with this band. the crazy thing is that it works perfectly now at home and i can't duplicate what happened on the gig. hopefully support can figure out exactly what happened

    Quote from tubelube

    If you could get fired for something out of your control you should consider looking elsewhere..

    i don't think i would be fired for something like this happening once. i CAN see it being a problem if it starts happening more often. hopefully this was a one time event and won't ever happen again

    My Kemper has frozen say seven times since the last September. What is interesting is that my spare Kemper, which is connected via the main one's midi through, hasn't frozen.


    By freezing I mean that the sound is on but the unit doesn't respond to anything except unplugging the power cable. After that it has worked good, until the next time it has happened.


    I get the midi PCs from QLab so the program does all the sound changes. One thing is also that the freezing has always happened at the same part of the show.


    I contacted the support and they suggested changing the order of the main and spare. I'm still in process of trouble shooting since the freezing happens so randomly and not so often that it is quite hard to pinpoint the problem.
    And of course it hasn't happened even once since I contacted the support.


    I've been always using the latest firmware release.

    Quote from jabromusic

    i don't think i would be fired for something like this happening once. i CAN see it being a problem if it starts happening more often. hopefully this was a one time event and won't ever happen again

    I agree. If it continues I could see it jeopardizing your position. Seems like you are taking the right approach with a backup available at all times. If it were me I think I would have the backup plan plugged in and ready to go for every gig until a time I was satisfied the Kemper wouldn't suddenly crash on me. Even then I would still have the backup readily available if needed.

    Quote from Grumpter

    I agree. If it continues I could see it jeopardizing your position. Seems like you are taking the right approach with a backup available at all times. If it were me I think I would have the backup plan plugged in and ready to go for every gig until a time I was satisfied the Kemper wouldn't suddenly crash on me. Even then I would still have the backup readily available if needed.

    usually, this particular band has plenty of time to set up and soundcheck so i will just keep my backup rig in my car. if i find that the kemper is frozen on startup i will have about 2 hours between then and the start of the gig. this particular gig was a wedding where all of the events (ceremony, cocktail hour, reception and after party) were in ONE big room. we all got there in plenty of time but had to wait until about 20 minutes before we were supposed to start to set our gear up (PA included). it was a big cluster&*%$. my next gig with this band is tonight so i will report back tomorrow. the good news is that the kemper has been working fine all week at my house. fingers crossed!

    Quote from citizengain

    One thing is also that the freezing has always happened at the same part of the show.

    Is there a MIDI event happening at this point or just before?


    When I was debugging my homemade MIDI pedal I could freeze the KPA with clumsy programming of my pedal, even though it would continue to play sounds.

    Quote from Gizmo

    Is there a MIDI event happening at this point or just before?
    When I was debugging my homemade MIDI pedal I could freeze the KPA with clumsy programming of my pedal, even though it would continue to play sounds.

    I notice the freezing when my rhythm sound doesn't change to the solo sound. This happens in song number 5. The problem is that the freezing could be happened at any point between that solo change or the last time the sound changed, which is in the song number 2. Between those points, it's only the same rhythm sound.
    I programmed the same midi sequence that proceeds the freezing into Logic and left it running a whole night, but couldn't reproduce the freezing.
    @Gizmo did you analyze what kind of midi command froze your Kemper?

    I've had the unit freeze due to USB-issues and on receiving external midi signals from an external source. On USB it was an issue with communications with Rig-Manager that supposedly was fixed in the last firmware update according to release-notes. The external MIDI source that caused problems was a MIDI-interface transmitting messages from a set-list-manager intended to control stage-lighting and all midi-equipment on stage during a show. The freeze on USB was resolved by disconnecting the USB-cable. RM would also have to be restarted. If not the KPA would freeze again once RM got re-connected. The freeze on MIDI-input was solved by re-booting the KPA. I don't know exactly what happened on the MIDI input to cause the problem, but I suppose it would happen over and over again if the external equipment would keep sending the same messages. Thus I think it is likely that your problem lies in the MIDI-controller. However, no device should lock up on erroneous input on any port. Any properly implemented device should interrupt and/or reset external communications within milliseconds if communications fail or the device is receiving erroneous/incomplete information. To simplify troubleshooting of such issues the KPA should have implemented a method to trigger a crash/stack-dump that could be sent to support for further debugging.

    Quote from citizengain

    @Gizmo did you analyze what kind of midi command froze your Kemper?

    It was not so much that the Kemper "froze". it was more that some errors during my MIDI SYSEX program development would keep the KPA and my pedal too busy trying to respond to very many repetitive commands, such that the KPA seemed unresponsive. The errors were mine, not the KPA, much like heldal describes.
    Just suggesting that something similar could be happening to you and when you programmed the MIDI commands into Logic, you may have not duplicated the error that you have with Qlab.