Hi pitched feedback after last update?

  • I'm suddenly getting really bad high pitch feedback on my gain patches when playing live through my KPA/Atomic. This is a new thing happening on patches I've used for a long time.
    It's feedback like a mic gets through a PA, not the kind we guitar players typically like. 8|
    At first I thought my pickups had suddenly gone microphonic or something but it's happening on my tele as well.


    Any thoughts?


    Thanks.

  • I used my KPA with my Mesa 2:90 tube amp & 2x12 this weekend for the first time in a long time and got this as well. Ran the KPA direct to the PA and ran monitor out to the tube amp (with the cab stack off the Mon out) for monitoring on stage. I am using the current firmware and never got this high squeal when I used it a couple updates ago. I mainly got it while trying to get natural feedback/sustain or if I pulled up the volume knob quickly from 0-10 it did the squeal.

    (RACK): Kemper KPA, ISP Decimator Pro G; (back of rack) Rack Solutions Power Strip, Xotic SP Compressor, Xotic EP Booster


    (PEDALBOARD): Kemper Remote, X2 Wireless, Visual Sound Pure Tone Buffer, Mission Engineering EP-1 KP, Digitech Drop, Rocktron Banshee Talkbox, Digitech Freqout, Xotic BB Preamp

  • I'm suddenly getting really bad high pitch feedback on my gain patches when playing live through my KPA/Atomic. This is a new thing happening on patches I've used for a long time.
    It's feedback like a mic gets through a PA, not the kind we guitar players typically like. 8|
    At first I thought my pickups had suddenly gone microphonic or something but it's happening on my tele as well.


    Any thoughts?


    Thanks.


    I have been playing in my last gig, last saturday and didn't have what happened to you. One thing it happened is that with high gain settings and high mesa 290 volume I got the same feedback coming from an unstable pickup. are you experienced this at high gain profiles?

    "...why being satisfied with an amp, as great as it can be, while you can have them all?" michael mellner


    "Rock in Ecclesia" - new album on iTunes or Google music

  • Yes, high gain profiles made from my Mesa rig. I had it happen with three different guitars. One with a DiMarzio Evolution and the other two had DiMarzio CrunchLabs, all pickups work fine with my Mesa Preamp through the Mesa 2:90

    (RACK): Kemper KPA, ISP Decimator Pro G; (back of rack) Rack Solutions Power Strip, Xotic SP Compressor, Xotic EP Booster


    (PEDALBOARD): Kemper Remote, X2 Wireless, Visual Sound Pure Tone Buffer, Mission Engineering EP-1 KP, Digitech Drop, Rocktron Banshee Talkbox, Digitech Freqout, Xotic BB Preamp

  • I'm not going to have this amp set up with the KPA again anytime soon, I typically run direct with IEMs, this was a one off gig I was sitting in with another band. I do know I eliminated some of it by turning the presence on the 2:90 amp down from 1/2 to about 1/4.

    (RACK): Kemper KPA, ISP Decimator Pro G; (back of rack) Rack Solutions Power Strip, Xotic SP Compressor, Xotic EP Booster


    (PEDALBOARD): Kemper Remote, X2 Wireless, Visual Sound Pure Tone Buffer, Mission Engineering EP-1 KP, Digitech Drop, Rocktron Banshee Talkbox, Digitech Freqout, Xotic BB Preamp

  • i have mine, the 2:90 presence at 9 oclock: didn't like the sound with higher presence setting. true though that my 290 have half el34 compared to all 6l6 as in the original setup

    "...why being satisfied with an amp, as great as it can be, while you can have them all?" michael mellner


    "Rock in Ecclesia" - new album on iTunes or Google music

  • I also have the half E34L & half 6L6GC power tube set up with JJ tubes

    (RACK): Kemper KPA, ISP Decimator Pro G; (back of rack) Rack Solutions Power Strip, Xotic SP Compressor, Xotic EP Booster


    (PEDALBOARD): Kemper Remote, X2 Wireless, Visual Sound Pure Tone Buffer, Mission Engineering EP-1 KP, Digitech Drop, Rocktron Banshee Talkbox, Digitech Freqout, Xotic BB Preamp

  • Did you get yours through Eurotubes too?

    (RACK): Kemper KPA, ISP Decimator Pro G; (back of rack) Rack Solutions Power Strip, Xotic SP Compressor, Xotic EP Booster


    (PEDALBOARD): Kemper Remote, X2 Wireless, Visual Sound Pure Tone Buffer, Mission Engineering EP-1 KP, Digitech Drop, Rocktron Banshee Talkbox, Digitech Freqout, Xotic BB Preamp

  • Awesome!

    (RACK): Kemper KPA, ISP Decimator Pro G; (back of rack) Rack Solutions Power Strip, Xotic SP Compressor, Xotic EP Booster


    (PEDALBOARD): Kemper Remote, X2 Wireless, Visual Sound Pure Tone Buffer, Mission Engineering EP-1 KP, Digitech Drop, Rocktron Banshee Talkbox, Digitech Freqout, Xotic BB Preamp

  • This just happened to me, running out of monitor out into Ambrosi then into CFR12.


    Drove me crazy for a while, went back a firmware, no help.


    Turns out the ground lift was the culprit, pushes the button and voila, no squealing!


    Try it and see if it's the same thing...

  • Huh, this is interesting. So you basically lifted the ground (pushed the button to the in position) and the squeal was gone?

    (RACK): Kemper KPA, ISP Decimator Pro G; (back of rack) Rack Solutions Power Strip, Xotic SP Compressor, Xotic EP Booster


    (PEDALBOARD): Kemper Remote, X2 Wireless, Visual Sound Pure Tone Buffer, Mission Engineering EP-1 KP, Digitech Drop, Rocktron Banshee Talkbox, Digitech Freqout, Xotic BB Preamp

  • From memory the button went to the out position. The squeal was only happening when I muted the strings and the guitar volume was up. Reducing the amp gain and increasing the noise gate went someway to helping but with more amp volume, the problem came back. I could even walk out of the room and the problem wouldn't go away, and it only stopped when I turned the guitar volume down.


    Playing wasn't an issue, only when I stopped (and it happened pretty quickly too). I can only think that the hum from the ground issue was interacting with the slight hum from the guitar, as well as the high gain of the profile, and creating some weird, high frequency feedback loop (maybe something to do with harmonics). I have a fairly noisy music room power wise so that's worth mentioning as well.


    I also had horrible him through my powered monitor at a gig once, balanced XLR from main out (had also run into stage box), this was on a clean profile but again the ground lift button fixed the issue.

  • New Kemper owner here... I was having this same issue and was becoming concerned that my unit had a problem. My tones were sounding horrible with the high-pitched squeals and I thought it was a noise gate thing -- but after upping the gate, my tone really suffered. But last night I found this thread and lo and behold the Ground button was engaged. After pressing the button, no more squeals/high-pitched noise. And finally tones are starting to sound as they should... Thanks!