Azure 2000 Sound-To-Light

[Tallysrfr]

I am trying to get the Azure 2000's Sound-To-Light function to work, but I'm having a little trouble. The board I'm using only has one input that I'm running L & R through with an adapter, instead of two like the manual says. I am getting the signal in (the led's blink to the beat), but it won't trigger even the simplest chase (on/off led bar lights). Perhaps I'm missing something. Can someone please help?
Thanks,
Bryan