Boyd failed to impress with Luton

The 25-year-old forward, who was released from his contract with Luton Town, has agreed a two-year deal.

Ling told the club's website: "Adam will be a great signing. He didn't have the best of times last season but he's a quality player."

Boyd began his career with hometown club Hartlepool and scored 60 goals in 169 games before joining the Hatters for �500,00 last season.