All of these devices treat guitar sounds, albeit in different ways. All are switchable and very flexible. It’s perhaps unfair to compare them directly as they do different things, but there is also considerable overlap, so here we go…
Background & overview
The Axe-Fx and X3 Pro are ‘modellers’ and work (variously well) on any guitar, whereas the GR55 combines Roland’s modelling with synth sounds and requires a hex pickup input. In the order I acquired them :
The Pod X3 Pro succeeded Line 6’s first rackmounted preamp/effects unit, the Pod Pro, and was quite a step up from it. Its main attraction was that it offers two parallel signal paths, so you can use a favourite studio engineer’s trick, bi-amping.
(Put simply, not only is this a good way of adding space and texture to sounds, but it can go much further. By running two amps in parallel, you for example get the percussive front-edge of a note from one and the sustained overdriven tail from the other, so you can combine classic amps to imitate the behaviours of the finest boutique amps).
The Axe-Fx and is successor, the Axe-FX II, define the state of the art in guitar amp modelling by using incredibly powerful processors accurately to model amplifier and effect behaviour.
The GR55 is Roland’s fourth (?) generation guitar synth. It succeeded the GR33, which I had, and is a big step up. With the exception of the piano sounds which are very glitchy, all the sounds track superbly.
All three units require a power amp and speakers or can be run through guitar amps or better, a desk and pa. All three can be updated using firmware downloaded from the internet and loaded using USB or midi. Firmware updates offer both new sounds but also performance improvements and a strongly recommended. Online patch exchanges exist for all three too, but in my experience you really have to hunt for good patches – most are for bedroom players.
The Axe-Fx is an amazing piece of kit. Having owned one for five years, I’ve got to know it pretty well and it can do almost anything an amp and effects units can. It’s unbelievably editable and controllable and the graphical PC- or Mac-based editor makes editing the multitude of parameters much easier than its own small green screen.
The onboard time-based/modulation effects are as good as anything else on the market almost regardless of price. Really expensive and lush-sounding.
But all that said, it doesn’t sound or feel quite like a tube amp even when played through a good tube power amp and dedicated guitar speakers. It does processed clean and more heavily overdriven sounds better than anything else I’ve used, but is less convincing in the middle ground of mild overdrive/volume control playing. Hence its widespread adoption by metal bands, some of whom have even eschewed their backline, which will be popular with their road crews!
I’ve tried an Axe-Fx II and it’s better but did not, for me, justify the additional outlay. Fractal’s customer service is also legendary, my only slight disappointment being that makers Fractal Audio stopped supporting the original Axe-Fx’s when they introduced the mkII. I would have expected them to offer ongoing firmware uprgrades and new amp models, albeit only once they had been offered to current mkII owners.
The Pod X3 Pro is much cheaper and sounds like it. Everything sounds compressed in one way or another. It lack real ‘spring’, ‘punch’ and headroom. Very ‘bedroom’ sounding.
It also has a key shortcoming, which is that it is not possible to control parameters in both channels of a two-channel patch in real time with many of the foot controllers on the market as they only transmit on one channel at a time and the X3 Pro requires two.
I was one of their very first UK customers and a keen advocate in their early years so I was really disappointed at Line 6’s reaction to my challenge of this which eventually became quite hostile as I pressed my point. Eventually, and no thanks whatsoever to them, I overcame this major shortcoming (especially when playing live), by going to the added expense of a Midi Solutions Event Processor, which can map commands from one channel to multiple channels.
On the positive side, the X3 Pro can interface and control a Line 6 Variax modelling guitar via a Cat5 cable, so with some programing effort you can in theory switch from a ‘Tele through a chorus and a Blackface Twin’ to a ‘Les Paul though a Marshall Stack’ with a single touch of your foot. But in reality, the sounds are not good enough to make this worthwhile and it quickly becomes a novelty. The best thing about the Line 6 Variax guitars is not their modelled sounds but the fact that they’re noiseless and have no magnetic pickups to gather hum!
The X3 Pro’s online editor and patch library are pretty good, though not up to the Axe-Fx’s pro standard.
The GR55 is the odd man out here as it’s a less comprehensive preamp/fx but adds a synth. By combining a straight through guitar path, a stripped-down version of Roland’s COSM guitar modelling from its VG88 product and two synth sources, it can cover a remarkable spread of bases. It’s a floorboard format and can also act as a foot controller for midi-enabled amps and effects.
In use, Roland’s COSM modelling is pretty good – certainly as good if not better than the X3 Pro’s, if not quite as good as the Axe-Fx’s. By going into its routing you can combine the real and modelled signal paths and create a pretty credible sort of two-channel/bi-amped patch.
And then you can go really crazy and add synth sounds too, some of which are fantastic as long as you don’t go overboard with the mix!
It too has a downloadable editor which is very easy to use – important when you’re editing synth parameters which make guitar ones like child’s play. And the online patch library and support are good too. I was trying to create a credible Arabic Flute and found other online users really helpful.
(I’ve only encountered only one drawback with GR55 – its predecessor GR33 could be triggered by an external midi source like a keyboard, whereas the GR55 only works with a hex pickup source like a Roland-ready Fender Strat or the like).
So you’ve probably already guessed that I’m keeping the Axe-Fx and the GR55 but ditching the X3 Pro. Next step is to acquire a Kemper modelling rack preamp, another different and complementary approach to creating sounds….