A plug-in company built to fund a modeler.

Neural DSP Technologies was founded in Helsinki in 2017 by Douglas Castro and Francisco Cresp, both from Chile, who had each first come to Finland as exchange students. A 2023 profile by the Finnish Venture Capital Association says Castro, a fan of Finnish metal bands such as Children of Bodom, Nightwish and Stratovarius, chose Finland when he won a high-school exchange scholarship, moved there in 2009 and founded his first company in Helsinki the same year. That company was Darkglass Electronics, the bass-pedal maker. Cresp, Castro told Guitar.com in 2024, “moved a few years later and we reconnected,” and the two worked together at Darkglass for several years.

The idea grew inside Darkglass. English Wikipedia says that in 2016 Cresp, then an employee, approached Castro about making an audio plug-in; the association’s profile says Castro had the idea for a new product as early as 2015. They chose to start a separate company. “Darkglass’s ethos and reason for existing was a company of bass players for bass players,” Castro told MusicRadar in 2022, and “credibility doesn’t transfer well from instrument to instrument.” He added that the hardware they had in mind was “a super-risky endeavour” that could have taken Darkglass down with it.

Software came first. Neural began recruiting in late 2017 and early 2018, Castro said, and released the Darkglass Ultra plug-in in April 2018 and the Fortin Nameless that September. The plug-ins, he explained, were a way to build the brand and earn revenue while a far larger hardware project was under way. Castro is chief executive and Cresp chief product officer, according to the Helsinki Times. Castro has since left Darkglass: in May 2022 Guitar World reported that Korg USA had bought a controlling stake in it and that, after selling his stake, Castro would leave the firm. That purchase concerned Darkglass, not Neural DSP.

Archetype, then the Quad Cortex.

Neural’s plug-ins fall into two families: amplifier suites and the Archetype series made with individual guitarists, among them Tim Henson, Cory Wong, Plini, Tom Morello, John Petrucci and John Mayer, according to English Wikipedia, which also says Mantra, a vocal-processing plug-in released in 2025, was its first product beyond guitar and bass.

The hardware was the goal from the start. “We started the company to build it,” Castro told Guitar.com in 2022 of the Quad Cortex, a floor modeler shown at the NAMM show in January 2020 that, the magazine noted, arrived in 2021. At launch Neural called it the most powerful floor modeler on the market, citing four SHARC+ processors; it added a touchscreen and a “capture” feature for copying a player’s own amplifiers and pedals. Development was hard. Castro called the Quad Cortex “a black hole of money for a long while” and said, “I did not know how hard and expensive it would be.” To speed up modeling the company recruited researchers from Aalto University’s audio DSP programme and turned to machine learning, and in 2024 it described to Guitar World a robot it calls TINA, which works an amplifier’s controls and records the results.

Smaller hardware followed: the Nano Cortex, which has no screen, in late 2024, and the Quad Cortex mini in 2026. Recognition has also come from outside the music press. Castro was named Finland’s 2022 EY Entrepreneur of the Year, coming first in a field of 51, MusicRadar reported, and in November 2023 the Finnish president, Sauli Niinistö, gave Neural DSP an internationalisation award as “Newcomer Company of 2023,” the Helsinki Times reported.

Modelers, profilers and plug-ins.

The guitar amplifier has split into two camps. One makes the amp out of code: a digital processor that models, or “profiles,” the sound of valve amplifiers and speaker cabinets and fits it into a floor unit, a rack or a laptop plug-in. The other still builds the real thing, with valves, transformers and hand wiring.

The digital makers are spread widely. Kemper is a German company, Kemper GmbH, which gives its seat as Recklinghausen; Christoph Kemper, who designed the Access Virus synthesizer, turned to guitar products in 2006, English Wikipedia says. Fractal Audio Systems, founded in 2006 to make the Axe-Fx, says its headquarters are in Plaistow, New Hampshire. Neural DSP, founded in 2017, is based in Helsinki, English Wikipedia says. Positive Grid, which says it was founded in 2011, began in California with a team in Taiwan and now dates its press releases from Chandler, Arizona.

One of these brands is part of a larger group. Line 6, founded in 1996 and based in Calabasas, California, has been part of Yamaha since 2014; the company says that led in 2017 to Yamaha’s first guitar division, now Yamaha Guitar Group.

The valve builders are both Californian. Two-Rock works from Rohnert Park, in Sonoma County, and has been owned since 2016 by Eli Lester and Mac Skinner, the trade press reports. Matchless, founded in 1989, says its amplifiers are wired point-to-point by hand in Los Angeles.

The modelers offer many amps in one box, updated by software; the boutique makers offer a fixed circuit, built by hand.

This guide sets out what can be checked about each brand — who founded it, who owns it, and what it says about where its products are made — and marks clearly what rests only on the company’s own word.

Venture-backed, with its own factory.

Neural DSP is privately held and backed by venture capital. The association’s profile says the Finnish-Estonian fund Trind VC invested in spring 2019 and that CapMan Growth led a new round in 2020; amounts were not disclosed. Trind still lists Neural DSP as an active holding on its website, and CapMan quotes Castro on its own site. We found no sale of the company in the sources we checked. The profile put 2021 turnover above €18 million, and the Helsinki Times reported revenue of €30 million for 2022; in 2021, MusicRadar reported, revenue was split equally between software and hardware.

The pandemic nearly ended it. Parts shortages meant that if Neural could not find components, MusicRadar wrote, “the company would have gone under.” Castro’s account of that period is also the clearest statement of where the hardware is made: “We do our own manufacturing, so we have people who work really hard in the factory.” Neural’s careers site says the company is headquartered in Helsinki, where its office houses more than half its staff, and that “our factory is close by, where we assemble Quad Cortex.” Those are the company’s words; it does not name the factory’s town, and we found no statement on where the Nano Cortex or Quad Cortex mini are assembled, or where components come from.

For a design guide, Neural DSP shows how a software brand with a distinctive name and artist collaborations can carry its identity into hardware. Compare Fractal Audio, the New Hampshire maker of the Axe-Fx, and TC Electronic, another Nordic effects name. For this guide we use near-black, slate and a cold blue with a geometric sans, an unofficial interpretation; no product or logo is reproduced.

Keep Neural DSP’s identity on hand — save it to a board in the Made Good inspiration library.