fireman

Hi, I have a mind twister here. I have a kw-12 sub with an okyo 7.1 amp. It was working great in auto mode while I had Cable vision (scientific atlanta box). Then I swithched to Verizon (motorola box) and they only have one set of analog outputs, which I needed to use to hook up to the tv. So I only hooked up the digital (optical) output to the amp. Well ever since my subwoofer does not wake up anymore. Could that bee the caouse or is it so,ething else? Do I need to connect the analog cables from the box tot he amp in order for the subwoofer to work? Please help.