Power amp suggestions

  • Hmm, really need support to wade in on this because as mentioned the whole unit is shutting down.


    I know it has protection on the power amp but yeah the sound just temp stops, not the unit shutting down. Also if you just pull the speaker lead out with sound, it doesn;t reboot.


    Dodgy lead could be a possibility as mentioned but certainly not normal behaviour - difficult to tell from the vid but I think I've played as loud as that no issues.


    Hope you get it sorted dude!

  • Definitely make sure to push the power cable in thoroughly before each use.

    Kemper PowerRack |Kemper Stage| Rivera 4x12 V30 cab | Yamaha DXR10 pair | UA Apollo Twin Duo | Adam A7X | Cubase DAW
    Fender Telecaster 62 re-issue chambered mahogany | Kramer! (1988 or so...) | Gibson Les Paul R7 | Fender Stratocaster HBS-1 Classic Relic Custom Shop | LTD EC-1000 Evertune | 1988 Desert Yellow JEM

  • ...you should also be able to see the wattage that its using under volume, which again would help in the diagnosis, but highly suspect you are not at the limits of the power amp...

  • I have had the same issue at band practice and don’t think it’s normal. I have tried everything as well and had to max out the Kemper power head until it shorted. I built a 4X12 Kemper kab and thought that would do the trick, and still the same problem. Because sound is not projecting forward like a guitar speaker would normally, the sound does not cut through the mix.


    My guitarist has a mini Mesa at level 1 and was still cutting through more than I was.


    I have now gone with a 2x12 mission Engineering cab which does not colour the sound and at the same time projects the sound forward which I am now able to cut through properly but barely. I had too turn up the Volume to max with the rig volume and now I have my max volume on the Kemper almost up all the way and the wattage meter goes to almost. 600. It’s loud but not as loud as you would think at that level.


    Standing in front of the amp at that volume, it was still bearable which is the problem. The 600 watts should be impossible to listen too from up close and with the Mesa turned up to 150 watts only, I was almost deaf lol.


    So not sure, something to work on for future models perhaps.

  • Very weird. I'm using a repurposed Fender Mustang III amp at a rehearsal space. Going into the return with the stock, 8ohm GT12-100, the 100 watts it has can be overpowering.

    600 watts and you can't cut through?

    I wish I had a better response than to say (again)....something ain't right.

    “Without music, life would be a mistake.” - Friedrich Nietzsche


  • What kind of speakers did you use in your custom built 4x12 and how were they wired?

    I think the Mission 2x12 is 16 ohms, and if you used 4ohm speakers for your custom 4x12 (wired in series) it would also have been 16 ohms....

    which means the power amp would only put out half its power rating.


    Even still, if you had it maxed out, 300 Watts is enough power to blow out most guitar speaker cabinets... Something might be wrong

  • I have a rehearsal tonight with my Kabinet so I'm going to see how many watts I'm pulling...I knowm its nowehere near the 200 watt speaker maximum

    I use my power rack through a 4 x 12 Marshall @ 16ohms and have the master at -17 and I'm lucky if I ever hit 50 watts, which on the meter is 200 watts. Always keep in mind about the wattage meter being calibrated for 4 ohms.


  • I have a rehearsal tonight with my Kabinet so I'm going to see how many watts I'm pulling...I knowm its nowehere near the 200 watt speaker maximum

    So, had rehearsal last night.....my set up is simply a power rack and remote and 1 Kabinet.


    Our drummer is not excessively loud but certainly gives plenty of volume...


    Turned up my power rack and played...the output was significantly less than 50 watts ( like a dufus forgot my glasses so didn't get an exact reading). I was also recording so couldn't take a picture....


    As a test I turned up to around 100 watts....no "analogue" drummer could outstrip that volume in my view. I chickened out going any higher...


    Interestingly I also tested some other profiles and found some better ones...i.e. cut through way better, so had to run my volume down...in other words, as we all know, its not about volume but cut as well.


    I still feel the dispersion is noticeably better than a guitar cab. When almost standing on top of my Kabinet vs in font at the "sweet spot" is definitely less of a discrepancy...

  • Could be I was trying to force a stereo rig with a radial cab-link? Mismatch in Watts or ohms?

    Do you use the serial or parallel input of the cab-link?


    Please try to run just one of your cabs, without the cab-link.

    That take it out of the equation for the test.

  • I know this isn't really helping but I was playing my 8ohm oversize 1x12 downstairs and felt like cranking it up. I had the wattage about halfway across the meter (about 28watts) It was SUPER loud. Things were shaking across table tops and amp racks. It was so loud my wife came down to yell at me and she never usually complains even when I'm cranking up my old 2204 Marshalls. Honestly I just cannot believe that that is only about 14 watts, that just cannot be?

    My power amp boost is on 2.5

  • I know this isn't really helping but I was playing my 8ohm oversize 1x12 downstairs and felt like cranking it up. I had the wattage about halfway across the meter (about 28watts) It was SUPER loud. Things were shaking across table tops and amp racks. It was so loud my wife came down to yell at me and she never usually complains even when I'm cranking up my old 2204 Marshalls. Honestly I just cannot believe that that is only about 14 watts, that just cannot be?

    My power amp boost is on 2.5

    Yes, it is astounishing.

    I made some tests yesterday night with a new beta software. We will add the PowerAmp Boost even for the use with the Power Cabinet, to achive maximum wattage.

    I was stunned how few watts make so much noise, again.

    I felt the need to make true voltage measurements again at the power amp output to check again if the Wattage Meter is calibrated correctly, or if I have made a mistake.

    But it is spot on!

  • One thing too I think about the power amp of the Kemper is, think about all the solid state bass amps that are pretty small but put out a lot of power! The Kemper is loaded and has plenty of power. I may hit 35 to 40 watts on some chunky palm muting stuff and that’s with a full loud ass metal band. Love this thing.

  • Yes, it is astounishing.

    I made some tests yesterday night with a new beta software. We will add the PowerAmp Boost even for the use with the Power Cabinet, to achive maximum wattage.

    I was stunned how few watts make so much noise, again.

    I felt the need to make true voltage measurements again at the power amp output to check again if the Wattage Meter is calibrated correctly, or if I have made a mistake.

    But it is spot on!

    Totally..I don't undertsand anyone even suggesting not enough volumefrom the KPA...