The deal marks a successful exit from the Surrey-based business for Matrix Private Equity Partners, which initially invested £6.5 million in the business in 2007.

Founded in 1971, DiGiCo designs and manufactures digital mixing consoles used for live music threatres and corporate market.

Denise Emmanuel, investment director at ISIS, says that DiGiCo is a ‘fantastic’ example of an entrepreneurial company and management team that is able to deliver growth in a difficult environment.

She adds: ‘The combination of leading technology and exports makes DiGiCo a prime example of just the type of business that private equity should be investing in.’

Since Matrix’s initial involvement the business has invested ‘heavily’ in research and development, according to a statement, growing turnovers from £8 million in 2007 to £22 million in 2011.

James Gordon, chief executive officer of DiGiCo, says: ‘This is a fantastic opportunity for DiGiCo to build further on our achievements of the last five years.

‘The company has rapidly expanded in a short space of time and the timing is perfect to add some new investment and experience to the team. ISIS’s historical knowledge of our niche industry is going to be very valuable as the company continues to evolve.’

The investment by ISIS is said by DiGiCo to allow its current shareholder base to realise their holdings.

Other experience in the audio market came in 2007 when ISIS exited its investment in loudspeaker manufacturer Martin Audio to US-based LOUD Technologies.

Bob Henry, partner at London-headquartered Matrix, adds: ‘DiGiCo has been an outstanding investment for Matrix with enterprise value having increased seven fold over four years.

‘This is exactly the type of business that Matrix likes to invest in and we are delighted to have a second bite of the cherry through our continuing equity holding.’