Amp Modeler Tests

I finally got a chance to A/B the Neural DSP SLO against the AxeFX SLOs. They both sounded very good, and there was not that “one sounds like cardboard” thing that you usually hear when comparing two modelers (especially when one of them is Native’s Guitar Rig). However, there were some interesting differences. As before, I switched off the cabinet modeling in each one and used a third party (Melda) cabinet simulation so that neither had the advantage of a matched cab. Both shared the same dry input track. Both were level matched and the A/B test used Hofa’s blind comparison plugin so I didn’t know which was witch until after I commented on each one. That was hardly necessary though because I could always tell which was which from listening.

The Neural DSP could best be described as extremely well behaved. The Axe FX sounded loud and disrespectful (at the same volume). The quality of the distortion was very similar. They sounded like the same amp. It was the things around the distortion that were different. The NeuralDSP almost sounded gated. It was like only the fundamental tone was getting through to the distortion. Anything below the threshold of distortion seemed attenuated and muted. Anything above the threshold was compressed by the distortion in a very nice way. This well behaved quality would work very well for recording. It’s like having an ideal amp with an ideal recording setup.

The AxeFX on the other hand amplified everything. All of the pick and string noise was there, as well as the body resonance of the guitar. You could hear body handling noise and a lot more harmonics of the notes and pick position. The softer notes slip below the distortion threshold a lot easier without losing volume. There was also an interesting glassy quality that sounds like “very hot tube glass”. I tested with both the “Solo 100 Rhythm” and Solo 100 Lead” models, and they both had these qualities. The Rhythm model distorted less completely than the Neural plugin and the Lead model distorted more completely (input gain set to start breaking up at the same point). Both had a smoother onset of distortion and a larger range of tones between clean and distorted depending on how hard the strings are picked.

To summarize, I think the AxeFX definitely sounds more like a real amp, with all of the expressiveness and noises that come with it. The NeuralDSP plugin is more like an idealized version of an amp which has been tamed and tailored to sound good for recording. Which one sounds better depends on the application. For live, in the room jamming the AxeFX is way more fun (I’ve gigged with various versions for years, and it lives up to the hype). For recording a tight rhythm part, the Neural plugin would be much easier to mix. For an expressive lead, the AxeFX would have more tonal variety. The more control you have over the strings, the better the AxeFX will sound. If you have less control over string noise and harmonics or you just want your playing to sound tight, the Neural plugin will help you sound like you’re playing cleaner. It was an interesting experiment, and cool to see how much more there is to tone than the sound of the distortion.

I had some other notes on some of the other plugins, but I can’t find them at the moment. I did like the Universal Audio plugins a little better than the NeuralDSP - but it’s not really a fair test, since the UA plugins have real DSP hardware like the AxeFX. If you’re looking at software only, Neural is probably your choice. I’ve also found since then that I like the sound of some of the SoftTube and Brainworks native plugins as well, but I haven’t done a side by side comparison. If anyone does, I’d like to read about it.

Absolute best sounding

    1. AxeFX
    1. Kemper

Best sounding, reasonably priced plugins

    1. Neural DSP
    1. Universal Audio

Useable sound, good interface

    1. Amplitube

Cool interface, bad sound

    1. Bias FX
    1. Native Guitar Rig