I got to hear, and play through, Joe Moore's Kemper profiling amplifier at EZ's place the other day.
It was connected up to EZ's 2x12 Marshall cabinet with G12H30s that I know very well. As a result the cabinet modelling/profiling whatchamacallit was turned off. It's slightly smaller than you might think. About the size of a small tube head.
I finally got to understand what the millions of buttons on the device's very unattractive interface are for. So nothing is redundant. You can control every aspect of a guitar rig from this one device. All your effects units can be used from profiles and individually tweaked.
The sound quality is well-beyond modelling amps and effects units–any of them. Every profile sounds
exactly like the amplifier or effects unit in question. So the Singemonkey is sold? Selling all his amps and effects to buy one? Not quite.
It sounds exactly like a recording of the amplifier. A good recording. A top-notch studio recording. But it doesn't give the feeling of a live amplifier in the room with you. For me, but not for everyone, the valve guitar amplifier is part of the instrument. The sound box of the guitar. It has a very different feel when you're playing it to the Kemper, or any recording of the amplifier.
This will make no difference to the audience. In fact, if I mic up my amp with say, a Senheisser E609,
it's not going to sound as good through the PA as the Kemper. But it does make a difference to me on the stage.
If I were using a Kemper, I'd ditch guitar cabinets (what's the point? Big heavy, and adding little to the Kemper's work-flow) and run a line to a powered monitor and straight to the PA. Guitar cabinets are totally redundant with this system, IMO. You want to run this stuff into a hi-fi power amplifier.
So do I think the Kemper is over-rated or worthless? Not at all. There's a kind of guitar player for whom this thing is heaven sent. The guitar player who is duplicating the sound of various recordings and guitar rigs professionally. You will not get a better duplication of those sounds without a truck-load of guitar gear (and it's unlikely that it'll sound as 'right' live as the Kemper even then). This is a single box that does everything. And it does it perfectly.
But if, like me, you're going for your own signature sound, this stuff is completely unnecessary. A single small tube amp will sound as good, and costs a fraction of the price. Why do I want 5,000 different amp profiles? I've got one that sounds frickin' awesome. And I also respond to the raw sound coming out of my loudspeaker. The Kemper gives phenomenal sound, but at one remove–the sound of the miked up feed from the amp.
You know what? If I could get the profile, just the one, of the Trainwreck Express, in a stomp-box with cabinet profiling and an out to the PA, and nothing else, I'd happily pay R2,000 for it as a backup system for when I don't or can't have my amp. That profile sounds like God. But the full Kemper is only truly worth it to a certain kind of pro guitar player IMO. For others it's overkill.
And I hope they won't make that stomp-box look like a karaoke system.