Posts by SgtPepper

    For everyone that are concerned about the obsolescent s of the NXP [FREESCALE/MOTO56K] DSP'S consider this ... Even if Kemper were to introduce an evolution product in the KPA lineup that utilized say an Analog Devices Sharc it would most likely utilize the initial framework [ Backplane card based architecture employed in the current model ] Seeing that Mr. Kemper is obviously a visionary in the product longevity department this KPA II or whatever form it takes would most likely have an updated display [Capacitive Touch Full Color ] ect.... which brings with it a much higher price tag that may leave some the existing KPA loyalist a little depressed.. [ Kinda like unsupported A-FX customers ] =O


    Alas salvation for the faithful may be already built into the road map.


    I am betting that Kemper's business model leaves none of the faithful behind....


    Since the KPA has been designed as a card based system it is highly probable that existing users could purchase a DSP CARD UPGRADE package that would be installed into your KPA [By an authorized Kemper Dealer/Repair Facility ] that would provide all the audio advantages found in any new KPA product release.


    For those that absolutely need to have the latest visual bells and whistles there will always be buyers but just think of the potential revenues generated if every existing KPA user were to purchase an Upgrade package? Only time will tell if this will come to pass. In the meantime the new reverbs and any other improvements [ Distortion and Overdrive Pedal Profiling Options] ? would be a massive step forward. Providing there is any program code space and DSP processing power left in the current hardware. Of coarse there are always work around's like performing a re-mapping of the code space to allow overwriting dedicated code blocks on the fly to perform specialized functions and or effects !

    Where there is a will...... there is a way !


    So the moral of this story is that I believe Kemper will be taking all of us along as the evolution of the KPA continues for many years to come.

    If I am wrong take comfort in knowing that at its core any KPA will be a great one !


    Can I get an " Amen " to that ! 8)

    Okay I once had an issue like this ... However I had the KPA configured to use one of the 1/4 inch controller ports to connect a volume pedal.

    When the volume drop happened I took the 1/4 inch jack and worked it in and out several times and things came back to life. My hypothesis is that the KPA's jack or the cords jack might have had some corrosion and made one of the connections to the KPA JACK float intermittently which can cause strange volume changes or even total loss. So its a little like snake oil but maybe even if your not using them that somewhere along the way the KPA might have got a little confused , scanned them and jumped to service the volume by mistake. So for the heck of it work a 1/4 inch jack in and out about 6 times on each controller jack and then fire up the KPA and see if this helps...

    If the problem continues and your not actually using the controller jacks for anything you could look to see if CONTROL 1 or CONTROL 2 looks to be assigned or better yet just simply perform a [ SYSTEM ] ( INIT GLOBAL ) Maybe there some boot control registers that have corrupted data that is causing the phenomena. Hope this helps ....

    Just from your description I think a Global Init maybe the magic bullet for this condition. But it wont hurt to give the jacks a slight work out as well.

    Hello,

    The Headphone Out on the Kemper at best using your 64 Ohm headphones can output max 54mw. Try those same headphones and adjust the headphone output control lower to see if you may be running out of headroom. Secondly make sure you are not clipping the input (No red blinking at all) Same with the Output Led too.

    If you clip those it won't be pretty. Lastly in the main ouput section you could try adjusting down the presence control in the Main Output Eq section between the range of -3dBu to -6dBu.

    See if any of this helped.

    If your looking for earsplitting volume from the Headphone Out you maybe dissapointed because it cannot source enough current at 64 Ohms. But it should sound great at low to moderate volumes.

    Lastly if you want the biggest headphone volume bang for your buck I suggest you get some professional headphones that have an impedance greater than 400 Ohms like even 600 Ohm. Then the headphone out drivers do not have to max out thier current drive to rock the house in your head!

    Hey I am trying to help this guy save a few bucks and time ... That is all ... Ohh and as far as the KPA hardware is concerned there is Nothing Special !

    Its Kemper's code that is very very special !

    I'd like to correct Nightlight's disinformation about my official position as it concerns the Christoph Kempers, accomplishments.

    I challenge you to find any quote where I diminished any of Mr. Kempers awesome accomplishments specifically the KPA.

    I will admit to questioning the programming abilities and logic of the people charged with writing the control surface code and the Midi implementation which to my knowledge Christoph is not specifically one of them.

    Are you one of them????

    As a matter of fact I have much more experience in Control Surface design and coding along with specific expertise in writing efficient Midi interrupt handlers and main loop service routines !

    I can say without any doubt that there is no excuse for any Midi product these days suffering from Midi Overflow Issues or CPU Stack overflow problems.

    Sound familiar????

    For the record... and to stimulate synapses and dendrite activity in your sleeping brain.

    Christoph Kemper's profiling algorithm is nothing short of pure genius which places him in good company of the likes of Les Paul , Leo Fender , Jim Marshall and Mike Battle.

    So Kemper FI! and especially to you personally FUGG YOU!

    I have one question .... When your using the Amplifi is it connected to a PC via USB?

    In certain circumstances if the Shield of a USB cord makes direct contact to a metal chassis this can cause a nasty digital ground loop !

    So say the Amplifi is connected to a PC via USB if the above condition happens since there will be some cord connection to the Kemper it very well maybe allowing USB packet chatter noise into the KPA. Try another known high quality USB cable ... Sometimes USB cables can have poor conductor isolation shielding

    NOTE:

    IF YOU ARE NOT USING A USB CABLE YOU MAY BYPASS WHATS WRITTEN BELOW.

    It does contain some information that may come in handy one day !


    THE ROOT OF ALL USB EVIL

    Or better yet ...

    Get the squeal sound to occur.

    Disconnect the USB cable if you are using one between the Amplifi and a PC at that moment.

    Did it go away ?

    Now I do not mean to be insulting but I have to ask the question.

    Are you sure the cable your using to connect the Kemper to the Amplifi is not only a shielded cable but a very well shielded cable.

    Sometimes its easy for people to make a mistake and find themselves using a speaker cable or a very badly shielded cable.

    Just turning over stones here !


    What to leave in and what to leave out !

    You cant trust China manufacturing to do things using proper engineering protocol !

    A product may work in a lot of ways although there might have been one tiny detail overlooked prior to and during production.

    FYI: Chinese manufacturing rarely performs any QC test procedures on production runs. A couple of units come off the line a production Engineer looks them over and then rolls the dice. Happens everyday all day long.

    The fact that the Roland device worked could be that Roland applied extreme babysitting measures to insure total ground isolation and RF filtering was performed on all inputs and outputs just in case some other China made device cut a few corners in their design !


    LETS CHECK THE USB GROUND ISOLATION of the LINE 6 AMPLIFI !


    1. Another test you can do is with a USB cable connected to the Amplifi only!


    2. Connect the AUDIO cable to be used with the Kemper only connected to the Amplifi.


    3. Use an Ohm TEST METER and set it to the CONTINUITY TEST [Beep] Function.

    Touch the two test probes together to verify the continuity function is working.


    4. Take one of the probes and touch it end of the USB cables outer shield while taking the other probe to touch the sleeve of the cord connected into the amplifi that would have been plugged into the Kemper. If you hear a sustained beep there is a USB ground issue with the Line 6 Amplifi !

    There is a work around that might work but lets see where this all leads to.


    Let me know what you find...

    I wish KPA would please change my descriptor to something other than Beginner? Thanks


    Cheers

    Mr. Nightlight, Great advise if money were no object.

    Going on the premise this customer doesn't have $500.00 Euro to burn on something that a pc repairman most likely can fix within 1 hr of bench time and $10.00 in parts seems like something that makes sense to try before shipping it off and waiting .

    Here are some variables that may change your opinion.


    1. This customer has owned his KPA for over 4 years.... ding ding ding... does this tell you something ? As in can we say OUT OF WARRANTY !

    So it doesn't matter if a chimpanzee looks it over first as it makes no difference at all if it cant be fixed locally then it would need to be sent back !

    There is a good chance it can be fixed locally... IMO as being dully qualified as one whom has designed such devices.


    2. Electronically speaking there is nothing complicated or special about the design of the Kemper. It is no different than a personal computer !

    It has high quality pcb's [circuit boards ] using high quality flexible ribbon cables to connect them. One skilled in electronics and PC repair would have no problem checking power supplies and diagnosing particular IC failures even without a schematic. This isn't nuclear science ?


    But I respect your opinion ... Maybe you can pick up the tab for this guy ! Then I would have to say Kemper Fi ! Hooray for him and Fugg You !

    Sounds like the power supply for the Main LCD Display and the Led Driver IC's most likely a [ 7805 voltage regulator ] could be the problem.

    Considering the unit is still running leads me to believe the problem is localized. I do not have a schematic for the KPA but 7805 regulators are very commonly used for these purposes. Another cause could be that one of several of the led driver IC's that are connected to the Main LCD Display Power Supply could also be the culprit too ! If one were to fail it can pull the entire Display power supply down as a result. In that event typically the failed IC WILL BE VERY HOT TO THE TOUCH ! If you want to attempt to spare yourself the 500 euro expense. Find a local electronics repair man and demonstrate the failure to him and see if he can quickly find the issue with a little power supply probing, finger testing and logical deduction.

    Note: I do not represent Kemper nor am I affiliated other than an owner like you.

    But...... I am quite knowledgeable in digital electronics .

    Good Luck :)

    I am assuming you are using a Guitar amp and cabinet live primarily and have this EQ to use when your in the studio or at home.


    If this is the case you could get the same approximation by using the Monitor OUT to your live rig with no EQ.
    Then use the Main outs for the full range system using the Main Out Eq . Just roll off the Presence -6 dBu to -10 dBu and that should get you in the ball park.
    If your bypassing the Kempers Cabinets then yes you might want to use a Graphic Eq and do a -4dBu per oct starting around 4kHz
    4kHz = - 4dBU
    8kHz = - 8dBu
    16kHz= -12dBu


    Now if you want to apply the end all beat all you would use a -24dBu/Oct shelving EQ set at @ 4kHz !
    If you look at the speaker response of a guitar speaker you will see a sharp drop off right around 4kHz !
    That would be what you are looking to replicate if you are not using the Cabinets in the Kemper.


    Or simpler yet When you play live I think you can disable the CABINETS and lock it.
    Then when you are using full range UNLOCK and enable the CABINETS and tweak the EQ presence in whatever outputs your using...


    Anyway something to ponder.

    Please tell me a few things about your rig...
    Guitar type Single coil Humbuckings?
    What Firmware version?
    Did you buy this new or used?
    After your response I'll shed some wisdom...
    FYI: I have owned my KPA since 2014. Despite the moniker associated ... I am far from a beginner and hope I can be of some assistance.
    I do not work or represent Kemper products.


    Ok I waited for you to chime in again to see if I could help... I assume that you either found a solution or will see this later. In any event I will generalize this response that applies to any of the KPA firmware and general operation.


    FIRST THING FIRST:
    No matter whether your KPA is used , new whatever firmware version it has or whether you have or have not updated the firmware do this now or anytime after you perform an update of the firmware or if one day you boot the KPA and it doesn't quite seem like it did the day before. I don't have the procedure in front of me but search for " GLOBAL INIT " procedure. The only downside is if you will have to reset the output and input parameters you may be using but that is a small inconvenience.


    • Init Globals - resets global system (and output?) settings to their defaults (will not delete/change rigs)

    PRESS the SYSTEM BUTTON then press the second button above the display "Init Globals"


    Did this fix your problem? If not continue to the QUICK FIX.



    THE QUICK FIX:


    What guitar you are using comes in to play here.
    The profiles you have purchased were created and tweaked using the individual profiling persons guitar to attempt a generic happy medium.
    It could be your personal guitar and pickups are different enough to create a mid honk maybe like that of a Duncan JB Model Humbucking !
    Great pickups but has that muddy mid honk....
    So a quick fix for this could be a simple as assigning one of the many Equalizer types to one of the PRE-AMPLIFIER slots !
    Like the first or second you can then scoop the mid range content a little EXAMPLE 450 Hz Q =1.0 -4.0 dBu and give a slight boost around 1.8 Khz Q = 2.0 +3 dBu
    Once you find the magic bullet then you can save your EQ as a preset that can be assigned to every other Rig you use with that guitar.
    Once you are happy with just one of your rigs then applying that Guitar Eq preset to other rigs should yield instant satisfaction !


    If you are not smiling from ear to ear at this point its time to go deeper !



    LETS DIVE INTO THE DEEP STUFF !


    As you may know the KPA has many useful features to sculpt your particular tone you have your standard front panel EQ then you have your AMPLIFIER section parameters that make a big difference in overall voicing's specifically DEFINITION, CLARITY, PICK, TUBE SHAPE , POWER SAG and BIAS these alone can make a big difference.
    From your description I suggest taking a rig that exhibits what you have described and adjust the DEFINITION and CLARITY see what you find .
    From there make sure POWER SAG = 0 as Power sag will essentially compress your transient dynamic range which will limit your attack then rise over time.
    Lowering POWER SAG to 0 will allow maximum peaks of chord chunks and soloing... But if you want the tube bloom affect you'll want to use the Tube Sag especially blues players !
    AMPLIFIER COMPRESSOR:
    The Compressor in the amplifier section is interesting as it will help accentuate your initial attack like a well tweaked tube amp does. The combination of COMPRESSOR, CLARITY , PICK and DEFINITION goes along way....



    If that were not enough you have tone shaping left to play with in the CABINET section


    It allows you to choose different cabinet types and then shape the final response with parameters to shift the CHARACTER LOW and HIGHS response.


    The AMPLIFIER and CABINET editing are very powerful and easy to use Tone shaping tools. You will quickly get familiar with them and how to apply them to get your personal tone footprint.
    .


    I hope this begins to open up the universe of tone capabilities the KPA has in store just for you !


    Best regards

    Too everyone reading this ..... This illustrates the knee jerk reaction of the Kemper team that comes into focus whenever there omnipotence is questioned at all.
    Agenda? The only one I have is hoping that KPA OS issues such as all these operational anomalies , crashes and any other weird unexplained artifacts are noted and addressed.
    I even offered to help you solve them????


    Did I not write the following


    " As an end user like you for the time being I accept all these things because the KPA produces some great tone even despite the direct leakage. Would I rather it didn't have this issue? Yeah.... I know its there and it is mildly annoying but not to the point that makes the product unusable. Maybe someday somehow by some quirk of fate one of the programmers or engineers will just happen to discover that something from within the countless lines of code or even an internal interrupt or memory arbitration logic flaw within the MCU that yields an implementation of a firmware worked around that fixes many of the unexplained issues once and for all.
    Just remember back to when KPA was first released. A milestone in of itself by Christoph Kemper as profound as those of Leo Fender, Les Paul, Jim Marshall and Mike Battle [Inventor of the ECHO-PLEX ] . "



    Are these words of a TROLL ????


    For the record I have over 20 years experience engineering Digital Pro Audio Guitar processors working with Moto ala Freescale 56K based ASSEMBLY code along with the User Interface Microprocessor assembly code as well. I am well familiar with the idiosyncrasies and unexpected issues that arise.. Now days your relying on your IDE to compile and assemble your code and most likely are trusting its output without question. That is the first mistake ! The second is poor interrupt handling protocols employed ! Midi Buffer overflows ??? Really ??? Never before have MCU's had more onboard memory ! There is no excuse for any buffer overflows ... That's your second mistake.... Its called sloppy programming or poor coding logic !


    Bottom line: Instead beating people over the head and berating them when they bring attention to these anomalies maybe you should consider that maybe you have a real problem that keeps waving a flag that you will refuse to acknowledge. That will be your third mistake... I can tell you that these strange things are going to keep occurring within every official release of FW update until the root of theses issues are discovered. I have faced these types of bug reports and I know they are not fun especially when they cant be replicated by the programmers. It dose not mean they are not real.... We live in an age that affords FW upgrades which also creates a environment of end user beta testers.. I worked in a time where the firmware was internally beta tested to death before any release because it needed to be as close to completely debugged as possible. Flash programming was not an option.
    As MCU's evolved with internal flash and more on board memory a lot of things became much easier !


    I think I also said that I love the KPA and would not consider using anything else as its sonic quality has yet to be surpassed.
    I am on your side ... If you cant take user comments objectively without attacking someones credibility maybe Kemper should do some serious staff house cleaning.
    He's got the money to do it. The basic pre-amp core of the KPA is nothing less than pure genius ... The rest of the product should be held to the same standards.
    There should be no excuse... How long has this product been out??? The operating system should reflect that don't you think? Midi Buffer Overflows ???? Your still having basic serial communications issues after 5 years of this products life ? That should tell you something right there... Its great that Kemper gave the OS programmers 5 years time to get up to speed. But maybe who ever is responsible for the current OS architecture should step down to a general programming position and someone brighter should be considered to restructure and optimize the Boot sequence, User Control Interface, General Main Routines , Interrupt handlers , Confirm MCU Memory buss arbitration via verification code , Thread management ect ... Basically tighten up coding logic and confirm the assembly output address declarations against the expected code map file. 5 years has been more than enough time to realize that some sort of change is needed.


    You can not keep doing the same thing and expect a different result ! Crazy man.


    My feeling is the current chief programmer is in too deep and has lost his way. I am not saying he is a bad programmer ... I am saying his program logic flow is really rough .... Its a talent ... There are programmers and there are others that have an expertise in operating system optimization and program flow execution.


    As I have indicated I am keeping the faith that great improvements will be made in the operating system that will make this product unstoppable now and into the future...


    So what kind of troll am I .... I am a proud Kemper-ite and will remain one until such a day that something comes into existence that surpasses the KPA's preamps sonic performance and user interface execution.


    I'm done now.... Think and say what you will ... Oh before I forget hey Locrain ,


    I mentioned the reverbs as a contextual metaphoric example ....


    As in


    Instead of finding and fixing the existing code .... More code is being written and being touted ... albeit a nice addition...


    What good is more bells and whistles if the basic vehicle keeps breaking down???????


    Has there been one totally stable official KPA firmware release? Why not ??? What precedent does this track record create.


    KPA sounds great but unexpected issues may occur when you least expect them.... Not to mention taking 50 some odd seconds to reboot ! That's the fourth mistake !


    Danimaetrix,


    Your not crazy , I am not troll, neither is anyone else that dares to say that the KPA may have some issues....


    The OXYMORON is that the KPA response exhibits the behavior of exactly what they claim to detest!


    They proceed to demean and diminish anyone's credibility when they don't like what your saying like a gang of arrogant scheißekopf A-holes !


    That is reason I have not commented in quite a while ... But this was an exception ...... I am always keeping tabs on whats going on here....


    Its cheap entertainment !


    Waiting for something good to transpire ... Like a 5 second boot ! That be a good start !
    How about a Midi Buffer that never has overflow problems... Lockups , Freezes ect....


    Best regards,

    I'll put my two cents in this discussion for what it is worth... You are not crazy or over analyzing anything here...
    I have had to deal with this phenomena ever since rev 3.00. It is real and for whatever reason the people in the drivers seat look the other way and say. " We have never heard of this before " " Maybe you are just imagining it ? " Yeah right ... That's their way of avoiding the issue.


    Here is my take coming from a perspective of actually writing signal processing code. There are two ways of introducing clean into mix.
    The first being done by the Hardware via codec internal mixer or digitally controlled analog circuitry functionalities and the second being performed in the DSP processing using the input buffers. It could be true that not all KPA's are exhibiting this... Mine and yours are...
    So what could be the source of this problem... If the direct is a function of hardware it could be a flaw in the codec that is not fully muting the input signal from the final output. The second and more insidious cause could be some sort of internal initialization of the DSP boot state or some rouge program pointer corrupting that memory location or even worse code mapping issues where all sorts of weird erroneous manifestations not unlike some of the post made in this forum that are met with you must have a bad midi cord and such. The Kpa for sure is awesome at its core and when the stars are aligned its as good as it gets. I'd love to help Kemper fix and find the solutions but they take the attitude that there is nothing wrong with their coding..... but they will be releasing some new reverb's soon ?


    The point I am attempting to make here is that there have been operational problems with this product for years that have never been fully addressed yet Kemper continues to move forward developing new features and improvements compacting the code to maximize memory within every new version release. Of coarse I will be pummeled for my opinions,,, That's ok ! I understand ...
    The KPA team is very sensitive and highly protective of their own.


    What If the problems that I have outlined above are the result of being caused by the compiler , assembler or programmers themselves.
    If so all of these strange anomalies will continue for the life of this product. For instance midi buffer overflows can cause problems in many ways such as unwanted parameters changing , system crash and weird happenings due to stack pointer overflow issues and memory buss contention. Issues of this nature allude programmers and some either haven't enough experience to know where to begin finding the needle in the code haystack or they continue moving forward hoping the problems will just go away.


    Believe me it is not fun or easy to take the bull by the horns and find the solutions. I have faced these exact challenges and know what the warning signs are and how to go about locating the causes and fixing them.


    On the other hand In the defense of the Kemper programming team chances are pretty good that Kemper has limited programming resources that are working on the latest and greatest algorithm improvements and literally cannot afford devoting indeterminate amount of time $$$ that could be needed to chase down all of the digital gremlins where ever they may be within the hardware or firmware .
    A programmers worse nightmares are the problems users experience that can not be duplicated in their environment.
    But even those anomalies that can not be replicated are silently speaking to them.... whispering " NASA we have a problem "
    Its a vicious cycle ....


    Moral of this Story:


    As an end user like you for the time being I accept all these things because the KPA produces some great tone even despite the direct leakage. Would I rather it didn't have this issue? Yeah.... I know its there and it is mildly annoying but not to the point that makes the product unusable. Maybe someday somehow by some quirk of fate one of the programmers or engineers will just happen to discover that something from within the countless lines of code or even an internal interrupt or memory arbitration logic flaw within the MCU that yields an implementation of a firmware worked around that fixes many of the unexplained issues once and for all.


    That is until the a new kid on the block builds a better mouse trap! Its just a matter of time.
    Just remember back to when KPA was first released. A milestone in of itself by Christoph Kemper as profound as those of Leo Fender, Les Paul, Jim Marshall and Mike Battle [Inventor of the ECHO-PLEX ] .


    Every dog has it day in the sun. At this moment Kemper is the top dog. And that's still very good for all of us !


    FYI: I have owned and loved my KPA since 2014 ... I am hardly a beginner with the product as well as other related aspects !

    Sorry to be the grim Kemper reaper here but I suspect a cold solder joint on that encoder or depending on the scanning scheme a bad encoder enable line connection or logic IC issue. Either way service maybe the order of the day. Sometimes it's the luck of the draw with electronic components. Doesn't mean all are bad just a few but that's no comfort when it's your device.

    I know a little about this product.


    For the Midi Mate to be fully compatible with the Kemper performance more the firmware would have to be specifically rewritten.


    But hope is not lost as you can achieve what you want by doing a few hours of work remapping the Midi mate.


    1. Set the Midi mates main Transmit channel 1 .
    Set the Kemper to 1 .
    Now start reading from page 24 of the manual. You will be editing SET 1


    Edit Set 1 and change the preset number mapping to correlate to your specifications.
    Example
    Recall Bank 2 preset 1
    Now edit SET1 so preset 1 sends PCH 5 or whatever you desire.


    If you want this functionality you can achieve it with a one time edit session. Make sure to do a midi mate data backup after your satisfied with your setup.
    Let me know what you find.

    I really hate to rain on your mcc love fest but any $100.00 midi controller with ext footcontrollers have been doing this as long as midi has been around. The Kpa team keeps wanting to reinvent the wheel and make it seem like it's the inovation of the century.
    Here's what inovation for Kemper would really be worth touting.
    Since the KPA team came from the synthesis world. How about polyphonic pitch to midi conversion generated by the Kpa?
    Now that would be something to hoot about!

    Even though you may or may not be using the external control ports please try this.
    1. Make sure both control ports are not assigned to anything especially volume related parameters. Note: You may want to physically scroll through a few of the parameter assignments for each pedal to reset them to the state you want them to be just for good measure. Do this even if it intially looks like they are unassigned. At least your hand touched the dial.


    Now this has happened to me before with previous KPA OS but I had a pedal connected to the port. Nevertheless this next thing worked to bring the dead back to life.


    2. Stick a jack in and out a few times on both pedal 1 and pedal 2 jacks. Could be some oxidation causing an open condition to be read yielding maximum value at boot applied to whatever had been assigned by you or some digital gremlin then at some point the jacks conduct if they are normalize to ground ( no jack plugged in ) and a change of state is detected by the scanning routine and for some reason the KPA thinks that pedal was assigned to volume , well you can see where I'm going with this. In any event say the pedal assignment variable was ambigously corrupted or had never been set by the human user and was
    interpreted as being Volume the KPA volume would go to zero. When you stick a couple if 1/4 inch jacks(Open not grounded) into both pedal ports and do not pull them out, if either of them where somehow assigned to Volume the value read assuming Kemper has pull up resistor bias should now be maximum.


    Therefore if an intialization problem exists as described above your volume should miraculously return.


    Since you mentioned re-booting helped it leeds me to suspect an initialization problem of some sort is occuring.


    Won't hurt to give this a whirl for the sake of science .

    Sorry for the coding protocol banter fellas.
    I'm sure TIMO got the gist.


    As for me I keep the KPA in browse mode and send PC a MCC messages as needed.


    But I have to say what was just quoted from the manual does appear to be a little convoluted at best.
    Reading between the lines I would put it this way.
    #32 0= Bank 1
    PC 0-127= 128/Performance.Slots=Rig#
    On that assumption since there are 5 slots hence the PC=0-124 per Bank.
    Just throw away PC 125,126 and 127,
    After you reach the 124 PC limit you send MCC #32 and new Bank Value
    Send PC =0 and do it all over again.


    But as a fellow guitarist and programmer possibly a more graceful aproach would be.
    MCC #32 VALUE= 0-120 Performance Bank Select.
    PC = 0-4 Slot Select.
    Simple to understand easy to program.
    Would make needing a calculator to get to one particular rig unnecessary.


    Alternatively you could use another MCC # and VALUE= 0-4 to pick the desired slot as well.
    Midi Apples vs Midi Oranges.
    Cheers

    Yeah that's a common response in these here Kemper discussions. It's called bad initialization procedures or something is randomly overwriting parameter locations used in the audio processing blocks. Both are not very nice.

    As to Timo's point . If a Midi Service Routine is written properly using an F7 termination Byte should Not throw any cog into your buffer service routines. If you happen read an F7 you set an Eox_Service_Flag and leave the interupt. Then check if there are any message service routine flags set in the main loop and act accordingly. If there are no other specifying service flags set you simply clear the EOX recv flag in your service code and be on your way. Your midi service routines should be written in such a manner to be absolutely bullet proof with All possible scenarios considered. So in affect the EOX should insure some sort of action is taken.
    So let me ask you a question. Considering an Mcc message you Can absolutely opt to either omit the Eox or use it is your service routine going to get confused then?
    As a secondary follow up say your receiving a Sysx message you have confirmed the header and product Id but some how a few transmission bytes get corrupted or omitted yet the Eox gets received? Do you loose your midi mind and attempt to service the message or have a mechanism to verify either the proper number of bytes ecpected? Naturally a preset dump would contain some sort of checksum. But I'm talking about say for instance a special command used for some internal function that you want to be private.
    If the message is not correct you just ignore it and clear the service flag.


    In the case of the Pc message if you serviced it before the Eox is detected big deal! what is the difference? You would clear the Eox service flag and be on your way. Its really not that complicated for you to anticipate that is it? Certainly nothing to blow the stack? Right?