Is it normal to have hum on complete silence with the Kemper?

single coil pickups are very sensitive to noise rom electrical sources etc. Does the noise reduce if you move around? Common culprits are computer monitors, dimmer switches, AC, mobile phones (try putting your phone in a different room or on flight mode).

Also, as obvious as it sounds, guitar cables. I was getting an unexpected hum the other day and it turned out that the cable between my wireless and the Kemper had started glitching. Switched cable, hum gone.

Another possibility is a ground loop. If you have gear plugged into different outlets on different circuits and you're getting a 60 cycle hum, one thing you can try is plugging it all into a single outlet (assuming it has the capacity) and see if it goes away. Others can speak more intelligently than me on this one. Debugging ground loops can be quite the hassle.

Of course, as a lifelong Strat guy I can testify to Alan's observation about sensitivity. If there's even the slightest possibility of hum developing in an environment, I can just place my Strat in the middle of the room and like a Ouija board it'll magically find it. It's like a sixth sense or something.

The hum thing is true not only with the Kemper but with any amp I've ever owned. It's just part of the Strat experience. And no, hum on a clean tone is not normal, even with a Strat. Unless I'm doing something to invoke the hum like standing next to a noise source, the Kemper is crystal clear with any of my guitars.

I don't even own a Kemper (just made my first post questioning as to if I should or not), but from other gear experiences...

In addition to everything people have said above about single coils and ground loops -

Most people don't realize how much noise there is on the amps that are being modeled. Think about it - when was the last time you had a 100 watt Marshall 8x12 cranked to 10 while standing inches away? Yet, this is the tone we are trying to replicate. And thanks to modeling, we can. We can have that tone coming out of our headphones without the deafening volume level.

Unfortunately, there is a lot of noise/hiss/hum on physical amps - even without a guitar being plugged in. It is totally natural. It gets included with models. In fact, without the hum, models can sound "blah". And the same can even be said for "noiseless" single coils - without that noise, you often lose the very tone that made you want a single coil in the first place.

Of course, without being in the room to hear what you hear, we don't know what kind of noise you have. You could have any number of issues. But, to answer the question as stated - yes, it is normal to have noise.

Quote from HardcoreNinja

Is there something wrong with my unit or is 100% this environmental?

I guess your Strat has 3 single coils and a 5-way switch.

With the pickup switch in position 2 and 4 the noise should be pretty much gone.

If that's the case your noise is 100% environmental.

Some clean profiles are noisier than others. I will get a bit of "amp noise" on some clean profiles even when using humbuckers. The Noise Gate fixes that.