Far too many to list, but here are the main things:
- Replication of existing amplifiers via profiling.
- Loudspeaker emulation using impulse responses.
- Deep editing of amplifier behaviour parameters (clarity, definition, pick attack, compression, tube bias and more)
- MIDI channel switching and expression.
- HUGE range of effects - overdrives, modulation, delays, intelligent pitch shifting, reverbs, wah and much more.
- Ability to make your own amplifier profiles (replicate your own amplifier).
- Multiple independent outputs for direct recording, monitoring, to power amp, digital outs.
- Versatility. This unit seems to cover all the bases for studio recording, but also is very well-equipped for gigging.
- Incredible effects. The quality is brilliant and there's pretty much everything you could need.
- Clean sounds. Many warm, realistic sounds.
- Light unit, but good build quality.
- Online forums with useful advice for the (inevitable) pitfalls of a new user and a wealth of information.
- Tweakability. There are many useful parameters that can be edited to tailor a profile (assuming the original is near what you're after).
- The supplied factory preset profiles of distorted amps are very disappointing (and the Kemper is only as good as its profiles). The way these profiles are created may work for the original user, but may not work for you. See summary for details.
- Price. Whilst you do get a LOT for your money, the Kemper is only good value if you actually NEED all of its features, and unless you are a studio owner or jobbing session player, you probably don't. Additionally, as far as amp sounds go, the Kemper is a jack-of-all-trades but master-of-none. It's good, but still a compromise - if you're in any way a specialist, you will probably find it good, but not $2200 good.
- Latency. Whilst the latency is acceptable for hardware monitoring (if you have a high-end sound interface that can do it) or for playing live, should you want to add your own effects in your DAW and monitor it in your mix, the combined latency of even a high-end interface and the Kemper results in a noticeable (and for me, unacceptable - YMMV) lag.
- Occasional fake-sounding noises. Whilst this may be down to individual profiles, there are things that are fine with a real amp, such as string handling and pick noises, which come through as fake and nasty (think plugging into a hi-fi) in the KPA. It's the same with Line6's Pod series or the old Rockmans. If you adjust your playing technique to avoid it, you can get around it - you have to adapt to it, or learn to accept it.
- Not easy to quickly get a good (IMO) sound from it. Whilst I like the depth of tweaking available, if this unit is supposed to appeal to traditional amp users, who are used to plugging in their Strat/Les Paul, turning up the volume and instantly knowing if the amp has potential, Kemper REALLY, REALLY need to do make it easier to get good results for guys who actually know what a real distorted Marshall sounds like (both recorded and in the room).
- No official computer-based editor. For a machine this complex, that is insane. I believe a beta version of a limited 3rd party editor is now available, but only for the PC, which is ludicrous considering how many pro audio guys use Macs.
Seems very solidly built.
No personal experience, but Kemper's techs (and even the inventor himself) are known to be quick, courteous and very helpful. If you find glitches or technical difficulties, apparently, they will work with you to fix them.
The official Kemper forums are a very good source of information - I was able to find solutions to several noob problems very quickly be searching the forums. Just by aware that some users have their egos tied to the Kemper - watch out for the bitch-fights with AxeFX users and don't dare tell anybody that your real amp sounds better than the KPA.
I've been putting off checking out the Kemper Profiling Amplifier (KPA) for a couple of years now, but finally decided to give it a serious test since hearing the testimony of Wolf Hoffman - I heard him using the KPA live on Accept's tour of Stalingrad, and discovered that all the guitars on Stalingrad were made using the Kemper itself.
Also, both famous dino producer Michael Wagener and Accept producer Andy Sneap have pretty much raved about the Kemper - although despite bold claims that you can't hear the difference between the real amp and the profiled version, Hoffman, Wagener and Sneap refuse to go as far as saying they'd actually get rid of their real amps for the Kemper.
I had 3 big questions over the KPA:
- Does it SOUND like a real amplifier?
- Does it FEEL like a real amplifier.
- If 1 & 2 are true, can I REALLY get that sound recorded by going direct to my sound interface and DAW?
As far as my expectations go - my requirements were very simple. I'm a dino-rock player with nearly 30 years playing under my belt and very sharp and discerning ears. I've spent a fortune on amps and gear over the years, chasing good tone - both for live use and (with more difficulty) for home studio recording.
I want the sound of a real JCM800 Marshall, well-mic'd and recorded, but I do not have access to the expensive microphones, preamps or studio needed to create it myself. My current best efforts have been to use a loadbox with my real Marshall JCM800, take a line signal from that, then use a speaker cabinet simulator VST in my DAW, using speaker impulse responses. So the KPA has to beat that.
I soon discovered that the factory-supplied profiles were a very mixed bag. The clean sounds were very impressive - although I have little interest in them. Most amp simulators can pull off good clean sounds - the real test is how well they can sound like a cranked, distorted tube amplifier.
Sadly, the factory preset distorted profiles were VERY disappointing. Flat and lifeless and curiously, despite the clear difference in character between Marshall and Mesa Boogie profiles, I discovered that pinched harmonics were first of all quite difficult to get, but more alarmingly, sounded almost identical, regardless of which profile I chose. I also found that string handling noise had a spiky, nasty sound - reminiscent of the Line6 Pod series or VST guitar plugins.
Power chords and riffing were adequate, and the FEEL of playing a real amplifier was definitely there. Dynamics were there and the KPA allows you to adjust pick attack, the compression, the power tube sag. There's a limited window of usability with these parameters though, as adjusting any of them very far gives very unusable results.
This brings me to the core issue I have with the KPA. And it seems obvlous, but it cannot be overstated. The Kemper Profiling Amplifier is only as good as the profiles it uses.
I spoke to my friend (a knowledgeable KPA user) about the problems I was having with the harmonics and he explained to me that the way that a Kemper profile is created is that you set up the original amp and speaker that you intend to profile so it sounds the way you want. You set up your microphone(s) and preamps and whatever else you use in your signal chain, so the sound from the mic(s) is just right and you hook it up to the KPA. The KPA sends various strange sounds through your rig and does its magic - this is the automated process. Then you have to "refine" the process by actually playing your guitar through it.
Now, Kemper doesn't actually specify WHAT you should play here and this step is a bit mysterious. But bearing in mind how differently guitarists play. Almost all the factory distortion profiles seemed incapable of producing a screaming, early Gary Moore/John Sykes-style pinched harmonic. Power chords and riffs were ok, but dig in for a screamer and the KPA sounded like I was plugged into the microphone input of a hi-fi. But if the guys who created those profiles didn't play any screaming harmonics or whatever through their Marshall/Boogie/ENGL, how would the KPA know what it's supposed to sound like? And if you don't make pick noise/string handling noise during that phase of the profile, how could the KPA reproduce that? It's not the KPA that is at fault, it's the person who made the profile.
Herein lies what I believe is the biggest weakness of the KPA (for me at least). If you want to be able to get ALL the nuances of YOUR playing through a particular amp, you're going to need a superbly made profile (of which there are very few) or you're going to have to profile that amp yourself. Which means that aside from procuring the amp you want, you need to be able to mic the speaker so it sounds great.
This is where it starts to fall apart for me. The ENTIRE reason for me trying the KPA, is that I am a guitarist - and NOT an audio engineer. I don't have a soundproof and acoustically treated room, nor do I own a $1200 Royer 121 ribbon mic, or a Neumann or an expensive mic preamp or any of the other industry-standard recording gear that is used to create professional guitar sounds in a proper studio.
When Wolf Hoffman recorded the guitars for Stalingrad with the KPA, he profiled himself playing his own amps. Well - Wolf is not exactly short of cash or gear, and he's close personal friends with (and a lives next-door to) Michael Wagener (producer for Accept, Dokken, Skid Row etc. etc.) - who owns Wireworld studios and knows more about mic'ing amps and dino hard rock sounds than anybody else on the planet.
I ended up purchasing some 3rd party commercial profiles from theampfactory.com. This place has some quite impressive audio samples of their profiles and from what I could hear, the guy doing the demo playing sounds at least partly similar to me - a clean, dynamic hard rock player. And I got MUCH better results than anything from the factory presets.
But all the while I was testing the KPA, I kept going back to compare the sound with my own setup - an attenuated Marshall, comparing both the "in the room" sound and the direct recorded sound (the Marshall going direct and using a VST speaker simulator). Despite the good progress I'd made with the KPA, it still fell short when compared to my own amp. Both in the room and recorded direct.
I did everything I could to give the Kemper a fair shot. At one point, I actually played nothing but the KPA for two days and I actually began to adapt to it. It brought a smile to my face (playing a Blackstar Series One profile). It's funny how these things are relative. Because I was really starting to think I could go for the KPA. Right up until I plugged my Marshall back in.
I told my KPA-using friend about this, and he urged me to profile my Marshall. He told me that I could profile a line signal from the Marshall's power amp and forget about microphones - then use the speaker sim that I currently use, and it should sound just as good as my own Marshall. I raised an eyebrow. $2200 to sound just like what I already have? AND add another 6ms latency to the chain? He then told me I could also convert the impulse response of the VST speaker simulator to a Kemper compatible format and then monitor it in hardware.
Cool. But that's $2200 to get what I already have, and to maintain the low latency I use, have to reprofile it every time I want to change an effect from my DAW? This is getting silly. Ok. So maybe I'm a specialist. But why shouldn't I be? When Wagener or Sneap say that "you can't tell the difference" between the KPA and the real amp, I DO believe them. But think about what they are actually referring to. These are music engineering experts who have profiled the amps themselves. They have world-class skills and professional studios and gear to create AMAZING profiles. And MOST importantly, they're talking about the same guitarist AND guitar going through the amp and the profile.
Don't get me wrong - the Kemper is good. It can sound good recorded AND it can sound good amped with a solid state power amp and sent to a guitar cab (I got some nice results with that Blackstar profile). But as nice as the results were, they were still a compromise and fell short of what I was already achieving through my own rig.
Your own requirements may be different. Maybe your playing style is more similar to the guy who created the profile you try. The best I can say is to try one out yourself. Perhaps the KPA is the best evidence yet that "tone is in the hands." If the guy who makes the profile doesn't cover all the bases you'll need, there's not much you can do, but make the profiles yourself. Good luck with that... Other players may get better results than I did - it could well be that I missed something very important, but I did my best with it for a week, with the help of an experienced KPA user to guide me, but I still couldn't get it to sound as good as what I currently use, so it went back to the shop.