In 1997, Mark established Ashdown Engineering, naming it after his wife's family name. From the outset, Ashdown set itself apart with its VU meters, bold aesthetics, and rugged, road-ready designs. The company quickly gained recognition for its ABM (Ashdown Bass Magnifier) amplifiers, which became the flagship line.

Artists gravitated to the amps' warmth, power, and reliability. Within just a few years, Ashdown had secured endorsements from a diverse roster of bass legends.

By the late 1990s, Ashdown amps were being used on major stages. Pino Palladino, one of the most respected session bassists, adopted Ashdown gear as early as 1998. Other players, from John Entwistle (The Who) to James LoMenzo (Megadeth), brought Ashdown into rock, medal, and funk circles.

Through the 2000s, Ashdown broadened its product lines:

• ABM Series - remained te professional standard.
• MAG and Rootmaster - lighter, more affordable alternatives, aimed at gigging musicians.
• Custom Shop & Valve Heads - hand-built UK amplifiers that paid tribute to traditional tube designs.
• Studio Range - lightweight, budget-conscious amps without sacrificing tone.

During this time, Ashdown also became known for its exceptional customer service. Industry figures like Geezer Butler (Black Sabbath) and JJ Burnel (The Stranglers) publicly praised not just the amps, but also the company's personal approach.

By the 2010s, Ashdown had become one of the most respected names in bass amplification worldwide. Key developments included:

• Signature Artist Amps - Custom models for artists such as Geezer Butler (Black Sabbath), Shavo Odadjian (System of a Down), and Guy Pratt (Pink Floyd/David Gilmour)
• John Myung (Dream Theater) and Nate Mendel (Foo Fighters) became prominent users, bringing Ashdown gear to progressive and alternative rock audiences.
• Introduction of Pedals & DI Solutions - Ashdown continued to extend its tonal expertise which included the Pro DI, Funk Face, and Mega Drive.

In the 2020s, Ashdown doubled down on UK-built craftsmanship while continuing to maintain a strong global distribution network. One of the most significant steps was the release of the UK-made UK-ABM-EVO IV heads and cabinets, which reinforced the long-standing heritage in professional bass amplification.

During this period, Ashdown has also expanded into bass guitars, introducing the Saint, Saint Soap, and Capri lines. Alongside this, the Custom Shop continued to flourish, with boutique, hand-crafted designs such as the CTM-100 and CTM-300 valve heads.

As of 2025, Ashdown remains a proud family-run business, firmly rooted at its headquarters in Essex, England. The company continues to be trusted by a wide spectrum of musicians, from grassroots players honing their craft to world-renowned icons performing on the biggest stages.