Rehearsal with Kemper Profiler Stage into audio interface but... without computer

  • At rehearsals, I usually plug my Kemper Profiler Stage into the PA, but with my new band they don't use a PA for vocals, the singer sings straight into a computer audio interface (Scarlett 18i20 third gen) plugged into a couple of (I guess) powered monitor speakers, neither Mac nor PC around.


    I admit it struck me, but the point is that it sounds fine. I wouldn’t have expected to use a computer audio interface without computer.


    The point is that I plugged my Kemper Profiler Stage L and R XLR Main outputs into the audio interface and it worked, but when the singer connected his microphone in any other Scarlett’s tracks (we tried them all), his voice didn’t sound. If I connected only 1 of the Kemper Stage outputs (L instead of L and R), then his voice sounded. I insist we tried to plug both Kemper and the singer's microphone into all the audio interface tracks.


    Maybe some of you have gone through something like this. Any idea why it didn't sound?


    If I connected into the Scarlett through one single Kemper Output (L), is it correct? And if it's correct, then maybe should I switch to Master Mono? If I did that, should I check the stereo based effects like delays or they’ll just go Mono without any other snag?


    Maybe should I connect through Monitor output instead of Master output?


    Thanks in advance and sorry if any of these questions is naive ;)

  • How does the interface know what other inputs to send to the L&R main outputs without information from a DAW program. The interface would have the settings to send 2 inputs to 2 outputs as default built-in but maybe not 4 inputs to 2 outputs without a computer connected to tell it to do that.


    Using computers on stage is just asking for trouble, IMO.

    Larry Mar @ Lonegun Studios. Neither one famous yet.

  • When using a single out on the KPA you need to select Mono out. The Kemper doesn't automatically sum stereo outs to a single output just by plugging into only the left out. Unless you select Mono out you will lose half of any stereo FX. You can test this by setting up a ping pong delay.

    But is it adviseable to use 1 single XLR output on the KPStage (previously selecting Master Mono in Main Output)? I think using only 1 out won't affect to the sound beyond what you already mentioned about the stereo/mono, am I right? Thanks!

  • How does the interface know what other inputs to send to the L&R main outputs without information from a DAW program. The interface would have the settings to send 2 inputs to 2 outputs as default built-in but maybe not 4 inputs to 2 outputs without a computer connected to tell it to do that.


    Using computers on stage is just asking for trouble, IMO.

    I guess you are right, it makes perfect sense to me. Thanks for answering!

  • There is nothing wrong with using a single XLR with output set to mono. You obviously won't get the full stereo effect but for most guitar parts that is no great loss anyway. I would never use stereo on stage.

    I'm not at the rehearsal place now, I'm at home and tried to reproduce the situation I'll find at the rehearsal place: connected 1 single L XLR with ouptut set to Master Mono into my M-Audio M-Track eight Interface, without opening the DAW Logic, well... it only sounds through one of the speakers... I expected to sound in mono through both speakers. Desperation level rising... ;)

    Later I also tried connecting a TS to Monitor Out L and later a TS to Send L, always setting output to Master Mono, but the result was identical. Desperation level keeps on rising... ;)

    Again, truly thanks for your support.

  • The 18i20 has a fair number of moving parts. I took a look at the manual (Scarlett 18i20 User Guide and a few things came to mind.

    1. There is additional software, Focus Control, that can control the configuration of the unit. It may be that settings can be made with the computer that stay with the unit after it's disconnected. I'd look into that. So, the first question is, how is the routing configured?
    2. Normally I'd assume a dynamic mic like an SM58, but this is an unusual setup so it's worth asking. Is he using a condenser mic that requires +48v power?
    3. Which outputs are you sending to the PA speakers? Again, grab the manual and confirm routing / Focus Control implications.
    4. From the manual page 11 (emphasis mine) - which input are you plugging into, and is he changing the input he normally uses to accommodate you?

    Inputs 1 and 2 – Combo” type input sockets - connect microphones, instruments (e.g., guitar), or line level signals here. Combo sockets accept both XLR and ¼” (6.35 mm) jacks. Microphones will normally be connected using XLR plugs: instruments and line level signals should be connected via ¼” (6.35 mm) jack plugs of either TS or TRS type. The preamp gain is appropriate for microphones when an XLR plug is inserted, and for higher level signals when a jack plug is inserted. Do not connect anything other than a microphone - e.g., the output of a sound module or FX unit - via an XLR plug, as the signal level will overload the preamp, resulting in distortion; also, if phantom power is enabled, the equipment may be damaged.


    These are just the things that came to mind with a quick glance. Audio interfaces like this are really designed with the primary use case being a DAW, so to use it as a mixer for live performance you may have to do a little RTFM to understand how it wants to be configured.


    Hope this helps.

    Kemper remote -> Powered toaster -> Yamaha DXR-10

    Edited 3 times, last by Chris Duncan ().