Have you contacted Arc? They might fix it if you send it in. I had a Sundown amp with an RCA connector issue and sent it to them to be fixed. Didn't take very long and was cost was reasonable.
My Current: 2010 Sapphire Black Metallic 335i /Sport/DCT/PDC/Nav/Black Leather/CF Wrapped Interior/Gloss Black Grill/More coming...
My Other: 2006 Audi A4/Quartz Grey/Black Leather/E-Codes/APR tune/19" VRM v708s/FK Silverlines/RS4 Front Sway Bar/S4 Mirrors/Black Grill/Arc Audio-Focal Sound system