Just read that the 'monitor out' has the same feed as the 'speaker out' - just a silly question:
Does this mean I can use the monitor out to power a passive normal guitar cab?
No you can't because the monitor out is not powered, only the speaker output is powered.
The monitor out is taken from the signal line just before the same line enters the Kemper power amp,and emerges after the amp amplified, as Power Out.
Basically, the power amp and an active cab you'd connect to the Monitor out would be in parallel.
Does it mean the monitor out and it's volume considered as a preamp and Speaker out as a power amp ? The reason i'm asking cause i don't why when i adjust the monitor out to for example to -20db, the same volume number shows up on the master volume at -20db. Shouldn't they be on a different control ?
Does it mean the monitor out and it's volume considered as a preamp and Speaker out as a power amp ? The reason i'm asking cause i don't why when i adjust the monitor out to for example to -20db, the same volume number shows up on the master volume at -20db. Shouldn't they be on a different control ?
It depends how you adjust the volume.
If you do it with the master pot and both monitor and main outputs are linked they both will change.
If you do it in the output menu they will remain independent.
If main out is not linked to the master pot it will rtemain independent (recommended setting).
In any case monitor volume will drive and control both the monitor output and the speaker output. This has nothing to do with preamp/poweramp.
Master Volume itself doesn't follow a dB scale as it could control multiple outputs linked to it simultaneously - each at a different level. And Master Volume is maintaining those different levels. Only the individual output volumes e. g. Main Output Volume follow a dB scale.
So if i need to adjust a level of volume from Powered KPA > speak out > Guitar Cabinet, should i use the master volume or the monitor output ? i felt that when adjusting the monitor output, the sound gets more body to it
Louder (to a point) always sounds better, so that might be what you're hearing when you turn the Monitor up.
A few times I've been jamming away and wondering why it didn't sound thick enough or punchy enough only to remember that I turned down recently. As soon as I turn back up it's all there. Not ridiculously loud.
So if i need to adjust a level of volume from Powered KPA > speak out > Guitar Cabinet, should i use the master volume or the monitor output ? i felt that when adjusting the monitor output, the sound gets more body to it
It depends which other output volumes are linked to Master Volume and which outputs matter in your case.
If your Main Output is connected to a mixing desk and also linked to Master Volume, raising Master Volume will increase volume of both: your guitar cab on stage plus the incoming signal at the mixing desk. If that isn't your intend, either just increase Monitor Volume instead of Master Volume OR unlink the Main Out Volume from Master Volume. If the Speaker Output is the only output you currently use, it doesn't matter if you are increasing Monitor Volume specifically OR use Master Volume to increase Monitor Volume. Soundwise there is no difference.
If you are using a current operating system, while you dial Master Volume a graphic comes up which shows the individual output volumes in dB. You see which output volume follows (linked) and which doesn't (not linked) and how their relative levels are maintained.
Just to add to Burhards point, if you are connecting to a mixing desk, unlink volumes and set the main output level ( most set to around -18db to avoid frying the desk.
You really don't want to be changing this output once set.
You speaker output will then operate from the master volume so you can set this level independently ( it can evn be on zero whilst a consistent signal goes to the PA.
This all depends upon what you are trying to do. I have the power rack and I use an unpowered speaker as my backline on stage (4 x12). I have my main outs connected to the PA directly via an XLR ( no mike..yey!). Volumes are all unlinked so I can control my on stage volume and not affect the out front sound....that is managed by the sound guy ojn the PA.
Hope that helps..
Thanks guys! this is very helpful 
Let us know how you get on!
