The company, founded in London in 1962, is one of the last manufacturers based in Denbigh West area of Milton Keynes.
Spokesman Graham Young said: “Maxwell House is the only building large enough to fulfil our needs and ensure we can still remain within the same area. Being on the same estate as the other property we occupy makes the management of our operations a lot more efficient.”
Commercial property agent, Lambert Smith Hampton acted on behalf of property investor Kenmore Capital in agreeing a lease with Marshall Amplification for Maxwell House.
Surveyor Paul White said: “It is fantastic to see Marshall Amplification expanding within the Denbigh West area. As the last manufacturer in the area we are keen to keep this well known icon, fortunately Maxwell House offers them exactly the space they need.”