Neural DSP Quad Cortex

The Neural DSP Quad Cortex is a digital floor modeler from Neural DSP that combines amp modeling, multi-effects and the maker's Neural Capture profiling system in one stage unit. It was first unveiled in 2020¹ and Neural DSP claims it offers "the most powerful floor modeller on the planet"¹². Beyond its stock amp and effects models, Neural Capture lets the unit profile a real amp and store the result as a digitized rig, which Neural DSP describes as "the most comprehensive and detailed detection system, and the most accurate and powerful digitized rigs on the market"³.

The unit is built into an anodised aluminum unibody enclosure with 1.8mm chemically strengthened protective glass manufactured by Corning, and it is made in Finland⁴. It measures 290 x 190 x 50mm and weighs 1.9kg/4.2lb⁴.

The controls: 11 footswitches and a 7-inch touchscreen

The Quad Cortex is controlled with 11 footswitches and a 7-inch multi-touch display⁶. Preset naming takes full advantage of the touchscreen with an on-screen keyboard⁷. The unit can be configured for Preset, Scene, Stomp and Hybrid playing modes⁹, and modes can be re-ordered, changing their order when cycling through Modes on The Grid⁹.

One thing MIDI users should know: when you re-order Modes, MIDI CC values do not adapt to the changes. By default, Preset Mode sits in Mode Slot 1 and is recalled via CC#47 value 0; if Stomp Mode is moved to Mode Slot 1, that same CC#47 value 0 then recalls Stomp Mode⁹.

Selected MIDI control assignments from the Quad Cortex's MIDI CC list¹⁰:

Power and connections

The Quad Cortex runs on a 12 V DC power adaptor, which is included⁸. Its rear panel carries 2x 1/4" output jacks, 2x XLR output jacks, a headphone output, MIDI in and out/thru, dual expression inputs and a USB audio interface with Cirrus Logic codecs⁸. Guitar connects to Guitar Input 1¹¹.

The unit has two expression pedal inputs¹². Neural DSP has tested the following pedals with the Quad Cortex with very good results¹²:

• Mission Engineering SP-1
• M-Audio EX-P
• Roland EV-5
• Hotone Soul Press
• Electro-Harmonix Expression Pedal
• Boss FV-500-L
• Dunlop DVP 3
• Dunlop DVP 4
• DOD FX-17

Using it with a real amp: the four-cable method

The Quad Cortex works with a traditional amp using the four-cable method. In a setup documented by KHE Audio Electronics with their amp switcher, the connections run¹¹:

1. Guitar connects to the QC's Guitar Input 1.
2. The QC's SEND 1 connects to the KHE GUITAR INPUT jack, sending the guitar signal after the stompbox section to the amp switcher's guitar input.
3. The QC's RETURN 1 connects to the KHE FX INPUT jack, connecting the master effects send of the amps to the input of the QC's effect section.
4. The QC's OUT 3/L connects to the KHE FX OUTPUT jack, sending the signal after the QC's effect section back to the master effects return and the power amp of the activated amplifier.

In this setup, the Quad Cortex functions as a mono multi-effect unit: only the stompbox and effect blocks are active, and all amp and cab modeling blocks are disabled. A Mono Loop Block is inserted to create the insert point for the amp's effects loops, and the preset must have all amp and cab models deactivated. The QC's own pedals (Boost, Overdrive, Gate and such) are used in front of the amps like normal pedals, and the QC's MIDI can remotely control the KHE presets during patch changes¹¹.

Setlists, presets and modes

Presets on the Quad Cortex are organized into Setlists. A Setlist can contain 32 banks of 8 Presets, and you can create as many Setlists as you like⁷. Presets save by default in the "My Presets" Setlist, with the option to specify another Setlist when saving⁷. The Library can store a maximum of 2048 Neural Captures and 2048 IRs¹³.

Neural Captures offer limited tweaking after the fact: just Gain, Bass, Mid and Treble, with a more limited range than you will find on an amp model¹⁴.

Durability testing

Before release, Neural DSP put the Quad Cortex through a series of environmental and vibration tests, with the unit powered on and a tone running through it to ensure it continued to produce sound¹⁷:

• Temperature: placed in a climatic test chamber for 15-minute intervals starting at 0°C (32°F) and 40% humidity, with the temperature increased by 10°C after each interval. It performed flawlessly through to 70°C (158°F), at a level Neural DSP says is expected of military specification components. At 80°C (176°F) the test was cut short after 10 minutes because testers had concerns about the internal battery exploding¹⁷.
• Humidity: passed a 15-minute test at 70°C (158°F) and 95% humidity with no issues¹⁷.
• Vibration: passed three standardized 30-minute vibration tests at random frequencies, matching a lorry or van, mild aircraft turbulence and severe aircraft turbulence, each with a 100% pass¹⁷.
• Resonant frequency: operational for the full 40-minute resonant frequency test and passed, with vibration amplitude increased up to 20 G¹⁷.

What reviewers said

Guitar.com gave the Quad Cortex a 10/10 review, calling it a game-changing guitar product of the decade⁴. In GuitarPlayer's round-up, Dave Hunter's overall verdict was:

In MusicRadar's 2026 multi-effects guide, Alex Lynham wrote:

Price history

The Quad Cortex launched at $1599/€1599²⁰, with 1000 units available for pre-order at the Neural DSP website³. Neural DSP raised the price in June 2021 because supply chain disruptions during and after COVID-19 raised component costs; with those costs since normalized, the maker decreased the global MSRP to $1699/€1699 (inc VAT) effective October 2, 2023²¹. Later published figures differ: Guitar World's 2026 review of the Quad Cortex mini lists the full Quad Cortex at $1,849, £1,449 and €1,585²², while MusicRadar's 2026 guide lists it at $1799/£1449/€1669¹⁴²³.

The Quad Cortex and the smaller Cortex units

The Quad Cortex now sits at the top of a three-unit Cortex range. The Quad Cortex mini, debuted at NAMM 2026, is roughly a third of the size and keeps the QC's functionality intact, with the same processing power, the same seven-inch screen size and the full Neural Capture technology²⁴¹. It has four footswitches instead of 11, and one expression pedal output instead of two, with a second requiring a MIDI connection⁶. MusicRadar's review found the mini's Etch-A-Sketch style editing easier to use than the bigger Quad Cortex's parameter assignment, and rated its sounds five stars, calling it "a little narrow in potential use cases within a live scenario, but a fantastic studio companion"¹⁴. The mini sits between the full Quad Cortex and the Nano Cortex in the range²⁴.

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