​​Neural DSP Quad Cortex vs. Line 6 Helix

Even if you’re new to the world of digital modeling and profiling, you’ve almost certainly heard of Line 6. They’re a household name in the guitar world, and have a number of excellent amps and FX units on the market. If you do follow digital processing, you’ve probably also heard of Neural DSP’s Quad Cortex. Both are stunning devices that offer a lot of similar features and some unique ones all at the same time.

In this KillerGuitarRigs Guide, we will be pitting these 2 processors against one another to compare and contrast in order to give a better idea which is right for you. To keep things consistent throughout the test, we used our Jim Root Telecaster and a Vox AC30 amp.


The Line 6 Helix was introduced in 2015 as the brand’s very first model to use their new HX modeling engine. It was a runaway success, and went on to birth a whole range of complimentary Helix products. They were some of the very first digital modelers that started prying old-school guitarists away from their analog gear and into the world of digital emulation.

Line 6 Helix Guitar Multi-effects Floor Processor Tone Demo

Until the Quad Cortex, Neural DSP were a software-only company. Their plugins were widely used throughout the industry (with big names such as Tom Morello vying for their own plugin suite), and so news of a physical profiler got the entire community pretty excited. The QC has quickly become an industry favorite, and has been taking on the establishment ever since.

Check our full QC review here.

Quad Cortex - The most powerful floor modeler on the planet


The Helix series is a little more affordable than the Quad Cortex. There are several Helix models available, usually starting at around $599 and going up to $1,500 for the high-end models. The Quad Cortex is still the only hardware from Neural DSP and typically retails around $1,850.


The Quad Cortex and the Helix series are very closely matched for usability. They are visually very similar (barring the rack-mounted Helix options) on both the hardware and software elements. Both have simple stomp button layouts, attractive, bright displays, and easy-to-use controls. On both the Helix and the Quad Cortex, we found we could navigate most menus and get to the simple settings we wanted very easily.

The Quad Cortex’s display does have an edge on the Helix line, in that it’s touch screen and can control pretty much every function of the unit. The Helix displays are bright and clear, but lack the touchscreen capabilities.

The interface on both devices was fairly similar, and it would seem as though Neural DSP took a little inspiration from Line 6 when it came to the layout. Regardless, both devices have very intuitive layouts that wouldn’t take a beginner long to figure out and master.

Capture Quality 

Neural DSP Quad Cortex vs Line 6 Helix: which one to buy?

Capturing amps, cabinets, and pedals is the Quad Cortex’s party piece, so there’s very little competition here. The QC can profile an amp directly within the unit. We tested the process by capturing our Bugera V22 during our Quad Cortex vs Kemper comparison, and found that it produced an indistinguishable emulation that we were beyond happy with on both clean and high-gain recordings. For this comparison, we profiled our Vox AC30, again both clean and dirty so that we could compare it to the AC30 model in the Helix.

With the AC30 profile recorded on the QC, we played some comparison riffs between the clean take and the distorted profile, and compared them to an AC30 model on the Helix. It was a very close match, but in the end the Quad Cortex just manages to capture more of the organic tube tone than the digital model. Despite this, know that the Helix model is genuinely excellent, just not quite as excellent as the Quad Cortex.

Because the Line 6 Helix is a modeler, rather than a profiler. It won’t record impulse responses the way a Quad Cortex or a Kemper will. You can manually create an IR recording outside of the Helix and upload it for use, but there’s quite a process.

That being said, the quality of the other pre-loaded amps that we tried in the Helix were outstanding. They sounded just like the originals they were modeled on and required little if any adjustment.

Available FX

Effects have traditionally been a strong suit of Line 6 products, so we weren’t surprised to find that the Helix’s selection of pedal models were extremely accurate. The models are built into blocks that can be combined to make a signal chain similar to an analog pedal board. The selection of built-in FX is especially impressive, and it includes just about every big name pedal you could imagine, in fact there are 231 built-in FX over 12 blocks.

As you’d expect, the models have had their names changed, clearly for copyright reasons, but Line 6 does provide a guide to the FX and names the pedals that their models are based on.

The Quad Cortex comes with 70 built-in FX presets over 32 different blocks. The signal chain is set up to allow 4 parallel FX sets to be used simultaneously, which allow us to get some really cool stereo sounds. We were able to get similar results with the Helix, however the Quad Cortex also offers the ability to use multiple signal paths.

While the Helix is packed with excellent models, it isn’t able to profile new pedals on its own the way the Quad Cortex can. If you’ve got an analog pedal that you want in your digital rig, the QC can fully profile it using Neural Capture Technology the same way it would capture an amp or cab.

The Helix picks up a slight advantage over the Quad Cortex when it comes to expression-based FX, since the floor-based LT (and above) models feature a built-in pedal. The Quad Cortex can accommodate external expression pedals, but they require a separate purchase, and not all models are supported, although our Jim Dunlop Cry Baby worked perfectly. Additionally, the Quad Cortex struggled with modulation and phasing FX when using expression pedals, whereas the Helix models fully supported their use.

Because of the Helix’s extended time on the market compared with the Quad Cortex, aftermarket support is a lot stronger. There are a lot more IRs available to download for a Helix than there are profiles for the QC. Although, the support for the QC is growing daily, as more and more players enter the ecosystem.

It’s also worth mentioning that the Quad Cortex doesn’t feature a looper. Given the cost of the Quad Cortex, this is definitely a flaw. The Helix has 3 looper blocks, including a 6-switch, a 1-switch and a shuffling looper.

Playing Feel

Quad Cortex vs the Helix, and why I sold one of them after I finished filming.

Given how much the two units look alike, from the form factor to the UI, the Quad cortex has a noticeably better playing feel. While there aren’t as many built-in FX or amp profiles, the QC has a much more natural sound. The Helix’s models are excellent, but you always get the feeling that you’re playing a model, whereas the Quad Cortex could genuinely pass for the real thing.

The Helix does excel when it comes to pure FX, however. If your priority is FX and you plan to play through a real tube amp, the Helix gives you an experience that is much closer to using a regular pedal board through an amp. So for live FX use, the Helix is pretty tough to beat.

Final Thoughts on the Neural DSP Quad Cortex vs. Line 6 Helix

While the Helix family hasn’t had quite the same time on the market as the Kemper, it’s still a much more established product than the Quad Cortex. Despite this, the Quad Cortex has carved a niche all of its own. In the studio, nothing comes close. The ability to reproduce tube tones like it can has made it a must-have for every pro and amateur studio alike. The Helix is still a phenomenal piece of kit. It’s versatile and having the option of rack-mounted or floor-based opens up a lot of possibilities. The Helix really shines when it comes to live use as a primary effects processor.

The pedal models are superb, and they’re ready to go right out of the box. The amps and cabinets are good, but they simply can’t match the QC for tonal authenticity, making the Helix a better choice for players who are more interested in FX than transitioning to a fully digital rig.


  • Simon Morgan

    Simon is an Orlando based musician, but originally hails from Newcastle, England. He started playing bass and guitar in 1998, and played the local scene throughout his teen years before life got in the way. Favorite Genres: Blues, Classic Rock, and he’s not ashamed to admit - Emo