Posts by heldal

    If I remember correctly the older units had an upgrade around 2020 (ish) to make them the same as the stage for SPDIF. Prior to the update they had to be set as the master for SPDIF clocking but after the update the Head and Rack were able t0 run as slaves. There might have been a few other minor changes in that upgrade but nothing that affects the sound.

    True. Forgot about that one. SPDIF improvement should be the only real change.

    An old device in working order does the job perfectly. All head and rack-units sold are functionally identical. Except from possibly the use of different but equivalent components in production over the years there have been no changes to the design.

    I haven't seen any integrated one-chip solution for a PoE powered Ethernet interface yet. You still need a PHY (physical layer chip) and a power acquiring circuit and a (preferably isolated) step-down converter to bring the PoE voltage to a lower level as required by your device. There are integrated chips containing the power circuit and the converter and the Remote uses such a chip. Basically, everything required for an implementation supporting both modes on the Remote would have been already there.
    However the Remote was released way later than the Profiler, where they had already made that bad decision to go for a propietary and spec violating solution. So they probably took the easy way, which was to just continue with that bad decision when designing the Remote instead of using the opportunity to get this right. As to what they were thinking, i have no idea and i'm not sure if we'll get an official comment on that.


    Here are power-sourcing IC's (need to be fed the correct voltages): https://www.ti.com/power-manageme…t/products.html

    These are circuits for the receive/consumer side: https://www.ti.com/power-manageme…s/products.html

    I bet several other manufacturers can offer something similar to those from Texas Instruments. It is a point that the KPA predates many of these products, yet most of the relevant IEEE-standards predates the KPA.

    BTW that is, why following specs is (or would be) such a great idea: You could just interconnect any Ethernet equipment without having to care about such details. There would not only be no risk of damage, it would simply work, literally, plug and play.......

    When the KPA is based on Ethernet/IP and there are PoE-enabled chip-sets readily available I struggle to even understand why they would deviate from the standard. What were they thinking?

    I'm trying to simplify my current rig and run my bass and acoustic through my kemper as well. Currently just using it for electric guitar. Is it possible to send 3 separate signals for each instrument to FOH?

    Why!

    It is not possible to have different signals going to different outputs, but I use my KPA for just about everything with strings on through the same two (stereo) channels on the mixing-console. Electric-guitars, bass-guitar, double-bass, acoustics (steel/nylon), mandolin, ukulele, banjo, lapsteel etc all works fine, and when patches for each instrument is set up properly on the KPA you don't need to do much on the console other than setting the input gain and mix. Matching output volume for rhythm/lead for the different instruments and patches is done by adjusting the KPA during band practice.

    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?