Kemper Profiler Rack VS. Fractal Audio Axe Fx II (Mark II)

So here is my personal take on the Kemper Profiling Rack Mount unit versus the Fractal Audio Axe Fx II (Mark II)…you will have to be your own judge and jury, because this is a super heated subject between guitar players and producers world wide and the debate is not going to end anytime soon…

Both of these units are digital preamps/amps, which can create realistic (nearly identical) simulations, algorithms, profiles and impulse responses of actual amplifiers, speaker cabinets and effects. I have spent countless hours over the past few months with both units and everything written here is my own personal opinion based on my own experiences both live and in a studio environment.

On first look (literally just opening the box and turning on the units), the sounds available from the Kemper are quite impressive and are definitely better than the Fractal units. You really don’t have to dial anything in on the Kemper straight out of the box. There are some really great factory profiles that are completely useable right away. With the Axe Fx II, you have to adjust the stock presets and EQ’s to get the same useable amp tones. It seems that most of the presets on the Axe Fx II are programmed to showcase the versatility of the unit and the processing power, which are also quite impressive. That being said, I am NOT choosing the ultimate winner of this highly debatable subject just yet…round one, however, would go to the Kemper Profiling amp straight out of the box!

I have the newest software/firmware updates installed on both units. It seemed the best way to compare all of the features to their fullest.

Kemper Rack Operating System 2.1.0 Public Beta released August 29^th, 2013.

Fractal Axe Fx II Firmware Version 11.0 released August 28^th, 2013.

These updates for both units are HIGHLY recommended in my personal opinion. On the Kemper, it unlocks even more features of the rack version that were previously unavailable, such as finally being able to use the rear, secondary input, which is honestly about time and a much welcomed software addition. Also, there are additional amp profiles, which are quite nice. On the Axe FX II, there are new upgraded preamp and power amp algorithms for all amps, as well as greatly improving the switching speeds of most presets.

On first experience, the Kemper appears to sound more hi-fi and articulate than the Axe-Fx II, however, after dialing in both units, that same hi-fidelity of the Kemper can also be one of it’s major downfalls as well.

My main goal of this entire comparison was to test the ability to “profile” or “tone match” a real tube amp and report the tonal similarities/differences I found. While I was doing this, I also formed a few other opinions about both units that I will also share in this review…

The amp I used to clone was my own design “Class A” Foppstar JL-18 head which is an 18 watt head into an oversized Foppstar 1x12 cabinet with a Celestion 65w Creamback speaker.

First up is the Kemper –

The results with profiling my amp with the Kemper were quite impressive at first. The hi-fi sound that I referred to previously is definitely evident the profile I created of my amp. The Kemper did a fantastic job of duplicating the dynamics of my amp and I was able to create more available gain on the Kemper than on the amp I profiled. I’m not sure if this is a good thing or a bad thing considering that my amp is a classic, vintage low to mid gain amp when cranked (Think Led Zeppelin / Thin Lizzy). One of the things the Kemper does not profile so well is the ability to maintain a consistent tone when you roll your guitar volume down. This is a huge downfall of the Kemper when profiling a single channel amplifier where you need to use your guitar’s volume to control the amp’s overall gain.

Second up is the Axe Fx II –

The process is a bit different to ‘tone match’ an amplifier with the Fractal. I had to record a riff with my amp and then use this track to loop into the Axe Fx II. Once the track was recorded and sent to the Axe, it creates a ‘tone match’ cabinet IR which basically takes the amp sim that I chose and creates a custom impulse response based on a mathematical algorithm of the frequencies from my amp. This Axe Fx II, created a much more ‘deeper’ clone of my amp with a mild tweak of the EQ on the newly created IR. The hi-fi sound from the Kemper is fantastic and horrible at the same time. With the Fractal, there is an undeniable low-end depth that the Kemper just cannot create no matter how much you tweak the unit. The Fractal excels at cleaning up your amp with your guitar’s volume control. So much so, that it almost seems to be more dynamic that the real amp itself…which can be good or bad just the same.

Round two would definitely go to the Axe Fx II. Although the Kemper did a fantastic job of creating a ‘portrait’ of my real amp, the updated algorithms on the Axe Fx II in firmware 11.0 definitely have more depth and a smoother high end response.

The effects in both units are actually fantastic and I would rate them all very high, especially the delays and reverbs. I would call it an even tie between both units in effects quality, however, there would be a slight edge to the Axe Fx II with the amount of different effects as well as the deep editing available within the Fractal. Round 3 would ultimately have to go to the Axe Fx II.

Just for fun I used both units to clone each other. I tried to profile the Axe Fx II with the Kemper (although they do not recommend profiling other modelers) and the results were quite horrible in all actuality. I can see what they mean once you profile another modeling unit. Then I used the Axe Fx II to tone match different profiles on the Kemper. Wouldn’t you know it, the Axe Fx II created a custom IR tone match just like it was cloning a real amp. After a few mild tweaks, I could not tell the difference between the Kemper and Axe Fx II when I cloned the Kemper. Round 4 goes to the Axe Fx II. I was actually very surprised this even worked at all, let alone as well as it did!

Next I tried to use both units with a tube power amp (VHT 2/50/20) as well as a solid state power amp (Electro Harmonix 44 Magnum) and a real cabinet (Foppstar oversized 1x12 w/ 65w Celestion Creamback) instead of direct!

First the Kemper –

You can disable a cabinet from a profile within the Kemper so you can swap cabinets or you can disable a cabinet completely to use with a power amp and cabinet. I tried this both ways with the Kemper and here is what I found…with the cabinet sims on with the Kemper, the tone was definitely negatively affected when using a cabinet profile with a power amp and cab. I would NOT recommend this at all!! Second, I turned the cabinets completely off and ran the Kemper through a power amp and cab. When turning off the cabinet within the Kemper, you actually change the entire sonic structure of the profile and the tone is just not the same no matter what you do. I also tried their new preamp only profiles available in the newest software version with a tube power amp, but even those just didn’t sound as good as the full amp profiles within the unit. The Kemper unit definitely excels at direct recording or using headphones as opposed to using it with a power amp and cabinet. This was not that big of a surprise considering 98% of the people I know using the Kemper’s only use them direct and use in-ears live. This is the best way to run the Kemper from everything I tried.

Second the Axe Fx II –

The Axe Fx II can completely disable a cabinet IR from the chain and allows you to just take the amp’s preamp. I also tried running the Axe unit with the power amp and cabinet IR’s on at first. This sounded horrible with both units…again no big surprises here. Next I turned the power amp sims off and disabled all cabinet IR’s and ran it through the power amp and cab. The global EQ of the Axe Fx II needs to be tweaked when using a real power amp (tube or solid state) or you won’t get the full dynamics available from the power amp itself. Once a few tweaks were made to the global EQ, the power amps worked great together with the digital preamp. I found that when using the solid state power amp, the heavier tones sounded a bit more compressed and were more round sounding. It lacked quite a bit of high end, but this could be compensated within the EQ for each preamp model. The other thing with the Axe Fx II unit is that you can run it in true stereo, which is also not available with the Kemper unit.

Round 5, again would have to go to the Axe Fx II.

Round 6 would have to be customer support and this hands down would go to the nice people over at Kemper. They probably have some of the best customer service response times and available solutions/answers for any issues you may face. They are honest and know there are a bunch of issues that are being worked on and software updates that will continually enable features within the Kemper that are currently unavailable. It can take days and even weeks to get a response from the kind folks over at Fractal. Once you do get in touch with someone over there, they are also very nice and accommodating, however, getting someone to respond to you in the first place just takes too long from a consumer/customer standpoint. Kemper wins this round no doubt!

Round 7, would be the ability to save and swap/upload presets. This round would go to the Kemper! The Axe Fx II has the brand new Axe Edit 3.0 software, however, it requires a computer to save and upload patches from device to device. On the Kemper, all you need is a USB stick and you can email files back and forth or just insert the USB stick into any Kemper and you can install any saved profile.  

After playing and testing both units, if I ultimately had to choose only one product between the Kemper or the Axe Fx II, I would end up choosing the Axe Fx II…

Here are the overall features that helped me decide to choose the Axe Fx.

Although the Kemper does create great profiles of your own amp collection, you actually have to have the amps/cabs/mics you want to profile in your possession or know someone who does to profile them. 

The Axe Fx II can tone match any Kemper profile out there as well as tone match virtually any direct recorded tone. 

The Kemper does sound great and more hi-fi, however, the Fractal has a better low-end response that the Kemper cannot duplicate and the Axe Fx II works perfectly with a real power amp/cabinet setup as well as direct.

The Kemper has a few millisecond delay when switching profiles and is definitely noticeable when playing live. The new updates to the Axe Fx II virtually eliminate any lag in preset switching. The processing speed of the Axe Fx II is just faster than on the Kemper.

In a live situation, if anything ever happens to your Kemper and it shuts down, or you lose power, it takes roughly 1 minute or more (depending on the profiles you have loaded into your unit) for it to start up and load. This is really a huge strike against the Kemper for me.

The Axe Fx II can be run in stereo and you can have two different amps running at the same time, one left, one right.

Many of the features within the Kemper are still in the development stages and certain features are on the unit itself, however, they are not currently enabled within the software.

 I do not use either unit direct, so the Axe Fx II’s ability to excel at sounding amazing with a real power amp and cabinet was really one of the major deciding factors for me.

In conclusion, both units are great at what they do and they both are an excellent product in regard to sound quality and the price for what you get! I would honestly use either unit at any given time. However, my personal preference is for the Axe Fx II. You don’t have to agree with me and I honestly don’t even care if you do or don’t. I only wrote this for those of you who have asked me to give my own two cents regarding both units side by side.

You honestly can’t go wrong with either unit. I just have my own reasons for choosing the Axe Fx. Over the next few months/years who knows what either companies will introduce or choose to update.

As with pretty much all gear, I have heard some amazing guitars/amps sound absolutely horrible and I’ve heard quite a bit of mediocre guitars/amps sound fantastic. Proof is out there everywhere that the best gear does not always mean the best tones and vice versa. I have heard several bands using both the Axe Fx and Kemper units live that sounded absolutely horrendous and I have also heard bands using both units live that sounded amazing and I couldn't tell they were even digital units. Tone is a very subjective and personal topic, so go try both units for yourself and then decide which one works best for your own needs. It is not a competition, I am NOT affiliated with either company and I would be more than happy with either unit in the end.  

For some of you out there (you know who you are!!!!), stop being one of the petty little gear whores out there that try to slam another piece of gear just because you spend $2000+ on something and are trying to justify your purchase. Your shiny new toy is not better than someone else's shiny new toy. :-)