Powered Kemper, but still not enough "power", needing an extra power amp?

  • 300 watts would also blow that 70W rated speaker.


    No one has mentioned the output section settings which typically involve a pad setting (volume cut - default is 12 dB pad (cut) which is a lot) for the Monitor Out.


    It is possible by adjusting this setting to boost the Monitor Out levels considerably (so that they are louder at the same settings on the front volume control) and also to see a meter showing the current power level which is an aid to protecting your speaker from overload.

  • 300 watts would also blow that 70W rated speaker.


    No one has mentioned the output section settings which typically involve a pad setting (volume cut - default is 12 dB pad (cut) which is a lot) for the Monitor Out.


    It is possible by adjusting this setting to boost the Monitor Out levels considerably (so that they are louder at the same settings on the front volume control) and also to see a meter showing the current power level which is an aid to protecting your speaker from overload.

    Erm because its a powered Kemper. The pad setting doesn't apply to the speaker out I don;t think, only to the monitor out.

  • Erm because its a powered Kemper. The pad setting doesn't apply to the speaker out I don;t think, only to the monitor out.

    My understanding is that the powered output IS for use as a monitor out. If you are powering Kones with it, only the Monitor Out offers the Kone mode DSP processing => that assumption is correct.

  • My understanding is that the powered output IS for use as a monitor out. If you are powering Kones with it, only the Monitor Out offers the Kone mode DSP processing => that assumption is correct.

    Nope...just tested it. No effect, which makes sense to me. The output levels to speaker, monitor out and main out are independant. Monitor and main eitehr go to a desk or powered output so input levels make sense. No need to pad a power amp...

  • Nope...just tested it. No effect, which makes sense to me. The output levels to speaker, monitor out and main out are independant. Monitor and main eitehr go to a desk or powered output so input levels make sense. No need to pad a power amp...

    OK - I see where you are coming from - and you are correct that the pad nomenclature only applies to the Main Outs and is not used in the control settings on the Monitor Out.


    Instead - I would argue - the "pad" or"12 dB cut" (below full output power) was previously always applied (not switched) for the monitor out and now you can reverse this 12 dB cut with the new 12 dB power amp boost control which was introduced with v8 of the OS. This is not a hardware change - the potential output level of the monitor out output circuit was always what it now is with the 12 dB boost fully applied, but in the past there was no way to crank it past the safety level which was set at 12dB below max level.


    Presumably this was so that people didn't accidentally blow their speakers feeding a hot full powered signal into the typical power amps on the market or into their tube amp's return jacks.


    BTW I am using a non powered KPA and the monitor out section in the editor now ( since v8 of the OS) has a radio button for Power Amp on/off and a rotary control for Power Amp Boost which tops out at 12 dB. The Monitor out and the Main outs would all be line level signals and I imagine with no pad active and the power amp boost up full the levels of these outputs would be comparable. Perhaps support can clarify.

  • I thought the speaker output on the powered Kemper delivers the exact same signal as the Monitor, but powered.

    The Monitor out on a non-powered unit is a line level signal (something like 3V peak to peak would be the max amplitude). The powered signal from the power head is going to have much higher output voltages - that is what amplification is - it is an increase in the amplitude of the signal, so the powered output would have much higher voltages and be able to deliver high current as well.


    A back of the envelope calculation - 600 watts is the stated limit for the Power Head and

    Power = Volts x current and

    at 8 ohms load: Ohms law gives

    Voltage = I x R = current in Amps x 8

    => 600/8 = current squared

    So solving for voltage too - maybe looking at peak output that is something under 10 amps max current and 80 volts max signal amplitude at full power (accurate RMS power calculations involve more complex math - integral calculus etc)

  • I think you misinterpreted my comment. I said the same, but powered. I understand Ohms Law and how power relates to current and voltage. Both have the same sonic characteristics apart from volume and Fletcher M effect.

    ?

  • ChickenPicker


    Do you send a Direct line to FOH via the Main Outputs?


    If so, have you Unlinked the Main Output from the Master Volume?


    From the Manual:

    Within the Output Section you can find individual volumes for different physical outputs.

    When you press the correspondent "Link" soft button in "Output Volumes" or "Output AddOns", you can link, or unlink, the respective volume to the MASTER VOLUME knob. Any linked volumes will be controlled by the MASTER VOLUME knob, without having to enter the Output Section again. You can link more than one volume to Master Volume – all linked volumes will be adjusted relatively to each other. All output volumes can still be controlled individually by soft knobs in the Output Section. An obvious live application is to unlink the MAIN OUTPUT connected to the main mixing desk of the venue – this means you can now change the volume of your monitor signal, or headphones, while the all-important main signal remains unchanged.



    Once you have done that - What is the Monitor Output level?

  • Thanks so much!


    I have to check this as well.

    Problem is that I am at home at the moment and over here it's more than loud enough :-)
    When doing rehearsal with band, I feel to have not enough headroom and very compressed sound.

    I will let you know when I have checked this :-)

    Thanks again !

  • Not sure what there is to clarify.


    Main and monitor out are line levels out, speaker out is a powered output. A Pad is on there ( as is the volume) to attenuate/control the output levels, so it makes sense to have that control at a line level.


    It makes less sense to have power boost on the non powered versions to me but hey...

  • It makes less sense to have power boost on the non powered versions to me but hey...

    I guess they are thinking that if you run an SD Powerstage (or something comparable) off the Monitor Out you effectively duplicating the circuitry of the Kemper power head but using an external Class D amplifier instead of in internally mounted one. Same issues apply with potentially blowing out speakers designed primarily to be driven by moderately powerful tube amps like the OPs 70 W driver.

  • I need more volume on stage.


    I think I am missing the boost power of my tube amps in the past.

    When doing rehearsal with band, I feel to have not enough headroom and very compressed sound.

    I've included both quotes because I think it might be helpful to better understand what you're missing in rehearsal. In particular, your comment about not enough headroom and compressed sound makes me think the problem you're trying to solve isn't necessarily just the raw volume db measurement.


    First, a little context. I have a powered toaster and prior to buying an FRFR, I ran into a sealed cab with a single Celestian V30 speaker. I could hit 105 db without breaking a sweat, and that's just where I stopped turning it up because even as a rock guy, that's starting to get a bit hard on the ears. So, I know the power amp will deliver the volume, but that may not be the entire story...


    I play classic rock, so more often than not the tones I'm going for are your typical Marshall on 11 kind of thing. When I'm pushing the speaker with higher volume, if there's some compression that's not a bad thing for my tone. Your user name is Chicken Picker, which would lead me to believe you play in a country band and thus have more need for clean and snappy tones with distinct attacks / transients.


    If you start getting compression with those kinds of tones, you're obviously going to feel it. A clean, high headroom sound at loud volumes will pierce your ears (if they're not pierced already) and can at times be painful because of the uncompressed transients. A rock distortion tone at the same db level isn't going to feel as loud as a completely clean tone at the same volume because of this.


    I mention all of this to offer another possibility for you to look into. It sounds to me like at rehearsal volume you're not hearing the kind of clean, twanky / spiky / sharp transients that you want in your tone, and you instinctively interpret that compressed sound as "not loud enough." Even if you fire up a db meter and it says it's X dbs and that's mega-loud, it doesn't really matter. All that matters is that you're not feeling the tone you want to feel.


    With that in mind, and because I'm pretty confident that the power amp in the Kemper is capable of delivering the raw db levels, you might try skinning this cat from a different direction. If you start with the working hypothesis that the power amp is capable of delivering the volume, that will then lead you to investigate other solutions. Consequently, the next step would be to search for profiles that deliver what you're looking for at volume.


    So, while not invalidating the question you've asked here, you might start another thread mentioning the kinds of bands / songs you play to give people a common point of reference, include the fact that a lot of profiles feel compressed at volume, and ask the guys what profiles they use to get the kind of tone you're looking for at rehearsal / gig level. These are a great bunch of guys and I think you'll get a lot of worthwhile suggestions that may, in fact, be the actual solution to the problem you're experiencing. At the risk of overstating the obvious, with a Kemper the profile is everything.


    For the record, I couldn't pick a chicken out of a police lineup, so I'm personally pretty useless to you in this regard. However, there are a lot of guys here and I'm confident that many of them need high headroom, uncompressed tones at high volume, so they can recommend some profiles that might get you closer to what you're wanting to hear.


    Hope this helps!

  • At the risk of overstating the obvious, with a Kemper the profile is everything.


    For the record, I couldn't pick a chicken out of a police lineup, so I'm personally pretty useless to you in this regard. However, there are a lot of guys here and I'm confident that many of them need high headroom, uncompressed tones at high volume, so they can recommend some profiles that might get you closer to what you're wanting to hear.


    Hope this helps!

    You made the point better than I could...


    There is either something wrong in your set up or its not volume but cut that is the issue.