Front input vs. alternative input

  • I stumbled over an old forum post that was a couple of years old, where a user said something along the lines of "the alternative (back) input is designed for line level signals". I kept searching and ended up finding a few more posts from different threads that all stated the same. I already know that the front input expects an instrument level signal. If that's true, this could possibly be a solution to a problem I am having, so I was excited. I am at work so I went to check the manual to confirm and there is nothing in the manual about what specific signal level the inputs are designed for. The manual only states that the alternative input can be noisier.


    So were they just blowing smoke or has someone official confirmed that indeed the front input is for instrument level and the back input is for line level?

  • I don't know about the exact levels but the alternative input on the back of the Kemper can take line level for sure, it is a multi purpose input. And: In the input menu you have to dial in which input for your guitar signal you use. So maybe the Kemper switches from line to instrument level automatically if rear input is chosen. Just a guess. In the past I've read several times that users are connecting to the rear input without an issue.

    I could have farted and it would have sounded good! (Brian Johnson)

  • So were they just blowing smoke or has someone official confirmed that indeed the front input is for instrument level and the back input is for line level?

    If this was so then you would get very different input volume/gain depending on where you plug your guitar. In practise I find the inputs to be just about identical when used with TS, except that anything plugged into the primary overrides the alternate input. I have my wireless receiver permanently plugged into the alternate, which leaves the primary/front input available for plugging in a cable whenever I don't want/need to be wireless. According to the spec there are some differences though: The front input is TS with 1Mohm impedance and dynamic range > 108dB while the alternate is TRS with ground-lift and dynamic range = 105dB. The behaviour of the alternate input depend on intput-settings, but when set to "input source" it behaves as I describe above.

  • One noteworthy thing I noticed about the alt input is that it's rated at 825k ohm vs the 1M front input. Not sure what that implies, but doesn't lower input impedance darken the sound of the guitar? Anyway, that's neither here nor there, your logic seems right. There should've been a difference in levels indeed so that's out of the window then.