Neural DSP Quad Cortex

Direct Monitoring feature still is unusable on Windows as of January 2022. I have tried every QC OS update/USB driver/windowsOS workaround on the PC of every bedroom producer I know and all with the same result. The entire signal gets bitcrushed when you record, fizzy unusable mush. Line-outs work just fine. Never had this issue occur on a Mac.

Side-note: I'm pretty disappointed that many teased features (such as being able to load Archetype plugins, having a desktop editor) have not been added and at this point never will be. I anticipate they'll put out a new unit with this feature in a few years and leave any early adopters in the dirt. This unit is rusting away, a waste of potential. The company's focus seems to have shifted almost entirely to their plug-in users. Not acceptable conduct at this price-point. I dare you Neural, prove me wrong in the next update

Lastly: flimsy unconditioned power supply, should come with something more reliable. USB 2.0 Type B is practically extinct why is it on this unit? Why doesn't the app have audio demos for user presets? Why is it so cluttered to navigate? Why is there so much latency switching presets?

First impression – einfach genial!

I bought this product in hope for a good sounding and easy to use unit. I own a Fractal Audio FM3. QC is the most user friendly unit I have ever tried - einfach genail! This is something the FA should learn from Neural. QC is also very lighter compared to FM3 and has lot more DSP power, you be very creative. With FM3 you can use only 1 amp in the chain.

What is my main problem with FM3, there are so many options and parameters to tweak, I have this constant feeling that I could sound better with some fine adjustment? With QC I have managed to set up the unit and create a patch in 15 min without reading any manual or watching any video, this is pure advantage!

What about the sound?

Happy with the thought that I will sold the FM3 and keep the QC, I set the A/B test. Both units had the latest firmware. I play 40+ years, owned and tried many high end amps (Friedman, Marshall, Mesa, Fender etc), owned digital stuff like Kemper, Helix and currently FM3. I argue that if you really want to test a digital modeler of profiler, you have to test it with guitar cabinet using a linear power amp (no IR). The test signal chain, my favourite Gibson Les Paul, AB switch, one line into FM3 one into QC and into a Matrix GT 1000 FX to the Marshall 1960 AV cabinet. I compared all the amps (same models) that are in the both units (Friedman, Soldano, EVH, JCM 800, VH4, VOX, Fender etc.). I tested from the bedroom to the stage volume.

And the result…

I could not believe and I didn't want to believe what I'm hearing. I was shocked, the FM3 sounded so much better, more fresh, more dynamic, much more real compared to the real amp. Just for the record, I tested the real Friedman amp BE 100 Deluxe, so I know how the real amp compare to FM3. In the end I kept my FM3, because it was so very close considering the feel, response and sound. And the idea to have many other amps that I love and don’t need to spend 20K EURO just for amps, is a good feeling. So, back to the QC sound, with the high gain amps, the QC has some strange, annoying frequencies in mid-range. Even with lowering the minds and EQ cuts, there is this 'nasal' thing going on. With clean amps it' even worse, I felt like having a blanket over the speakers with the QC. I thought I'm doing something wrong, so I checked many videos any read the manual. Tried other settings, options, but the significant difference was always there. In the blind test I could guess 10 times in a row which one I'm playing.

I'm really disappointing, because I wanted to keep the QC for it's simplicity.

Neural marketing strategy?

Maybe the user friendly product that combines two worlds (modelling and profiling) is the USP for the Quad Cortex? I don’t know, but for me, the number one criteria is always the feel and the sound.

I wish Neural could do something to improve the sound quality. With the sound of the FM3, I would keep the QC for 100% even the FM3 feels more robust, but I will not deep into this topic. Simplicity would be the game changer for me.

Verdict

If the feel and sound is your main concern, I suggest you try Fractal FM9 (you are not limited with just one amp in the row and you have more switches compared to FM3) and QC. Make sure you test it with a quality linear power amp and the guitar cabinet and choose your winner.

If you are looking for a decent sounding product with an unbelievable simplicity and countless options including profiling, the QC is the choice for you.

I will send my QC back ASAP (I know there are many of you waiting for the stock), sell my FM3 and buy an FM9. The 400 EUR + for FM9 compared to QC is nothing if I consider the sound and feel quality from Fractal Audio.

Thank you Thomann, you are the best retailer in Europe, no wonder that all shop in the circle of 500 km around my home, closed their business or they are selling only super low costs instruments.

As soon as you open the box and take it out you feel the quality straight away. The Quad Cortex is simply lovely to hold and looks sleek and modern. The touch screen makes it look on par with an iPhone or Android device. The fact the stomps double as knobs make this super easy to use.

This ease of use is my favourite thing about the QC. My previous modeller was always hassle for dialling in tones, particularly heavy tones, and always sounded a bit plastic. When I enquired about it on the related forum people were recommending third-party IRs. The QC, on the other hand, works great out the box with no IRs needed as the ones supplied do the job.

If there's any downsides it still needs some features like a looper and desktop app, and some more models, but like all of these types of devices its an ever evolving platform and they're sure to come.

I think overall, though, this device has been a great purchase. I've spent far less time dialling in which means more time playing and simply having fun. If you are already familiar with the plugins and love that sound then this device is highly recommended for if/when you decide to start stepping out of the bedroom.

Oh man, where do I start.

I’ve been using the Quad Cortex for about two and a half years now in different setups, including composing, home recording, jamming, and live gigs, and it has been quite a rollercoaster.

When I first booted it up, I was honestly disappointed with the stock presets. It took me hours to get a sound I actually liked. The fuzz pedals are especially underwhelming. The Neural Cloud website, where users can share presets, is also frustratingly buggy and not enjoyable to use.

The user interface on the unit itself is intuitive and easy to navigate, though navigating presets can be a little annoying and filtering them is a bit inconvenient. There is a lot of potential for quality-of-life improvements, and NeuralDSP could really benefit from looking more closely at the UX flow of phone apps to make the experience smoother. It is also supported by a desktop app, Cortex Control, which generally works fine but is still incredibly buggy even years after release. I have had countless app crashes, which can be very frustrating when editing.

One thing I absolutely love is the form factor. The QC is compact and easy to carry, and I can fit my whole rig - the Quad Cortex on a Rockboard TRES 3.0 pedalboard with a Mission Engineering expression pedal, neatly into my backpack. It is perfect for musicians on the move.

Where it really falls short is the lack of progress. Updates are few and far between, and NeuralDSP’s communication is practically nonexistent. Many of the effects they announced long ago are still missing. With the constant bugs, glitches, and slow development pace, NeuralDSP still almost feels like a startup rather than an established company. I have also had a warranty issue a few months ago where the I/O board developed a buzzing noise on both inputs. It was repaired in about two weeks, but I had to pay 60€ for shipping, which stung a bit.

Honestly, this unit should be in a much better place by now given how long it has been on the market. Years after its release, it still struggles with basic bugs (Cortex Control, Cortex Cloud), missing features, QOL features in general, and inconsistent software updates. For the price, I expected a more polished and reliable experience, and it’s disappointing that NeuralDSP has not delivered on that.

Sometimes I even fear that NeuralDSP has realized it cannot deliver on its promises. At times it feels like they are slowly abandoning the unit, with long gaps between updates, delayed releases, and little communication. It is hard not to feel that the product’s long-term support is uncertain.

Part of me wishes I had gone with a Line 6 unit with a similar footprint. At this point, I would honestly suggest looking into that ecosystem instead. I just do not have much faith in NeuralDSP’s ability to deliver on its promises or keep up with the competition.

I bought my unit in April 2021. Now, in August 2023, basic features like a file manager, desktop editor, and others are still missing. The overall pace of updates and communication from NDSP is a bad joke.

In my studio, I have 10 other competitive units (a few from Fractal, Kemper, Helix, and more). All these are complete products where "day one" and other major updates come in regularly.

From NDSP, instead of updates, we get monthly development updates in the form of generic blog posts, where customers don't get specific details, just their typical "soon". This has been the case for at least a year straight now. No major improvements or delivery of features that were promised shortly after the QC launch. Instead, they constantly release new ampsim plugins to keep the money flowing.

In terms of sound quality, the number of effects, and amp simulations, the QC doesn't really stand out compared to its competitors. I'd even say it's somewhat lacking, with competitive units in a similar price range offering more.

The QC certainly has great potential, but this approach by NDSP and the ensuing frustration that has been ongoing for nearly 2.5 years, ruins it all.

We all know what this unit is.
Made of a really nice metal case, slick, elegant, quality on the IRs and all its features, responsive screen, rotary foot switches, sturdy glass on the screen, wifi, possibilities of amp captures and more...
One thing broke my heart a bit. For an unit costing this much and being soo popular, built with this much quality and care, seems that a batch has BACKLIGHT LEAKS on the corners (other users has reported this on the internet).
The reply from Thomann and Neural DSP, apparently is that this is normal.
While the screen is fully functional and nothing seem to be wrong with it, respecting touch feature, as soon as you look at the screen from just a bit of an angle, you will notice a big purple/blue-ish stain on one of the corner from it.

This is not really nice, as for this price and this hype, I wasn't expecting less than perfection.
I have had units that cost 10x less than this product and they DONT have this issue (Mooer 250 and NUX-MG30).

Im a bit heart broken that this was their reply to quality check to be honest.

Some would say: "But it doesn't affect playability, you should not care..." -Well, some purchases are not simply made to gig and that's it. Some purchases mean a bit more that just the item, because they cost hard earned money and specially if you have been waiting for restock for 2 months like me.

Im satisfied with the quad cortex, but still, a bit heartbroken.

As someone who is not a professional musician but has been into music for quite a long time, I viewed this device as a "Turn on — Play — Turn off" solution. Many in the guitar community recommend "Computer and plugins" as the best option for home playing. But no, that’s not for me. For me, connecting to a computer, opening a DAW, creating a track, adding a plugin, and so on has always been a burdensome task.

In general, for my needs, the Quad Cortex looked perfect—and that’s exactly how it turned out. It’s an excellent device where you can simply plug in, quickly dial in the sound you need, and play. On top of that, I really like what Neural DSP has done with their community, where everyone can share presets and neural captures. This adds a certain element of exploration and discovering something new, which is also very engaging.

I don’t know how this device feels in the hands of a professional, but for home use, I can’t imagine a more perfect option—a big screen, great sound, a beautiful device for the shelf (yes, that’s important too), and it’s just pleasant and enjoyable to use. The new updates are also pleasing, though I’d like to see them be a bit more extensive.

If you, like me, are looking for a simple and convenient tool that quickly gives you a great sound "out of the box," this is the choice for you!