Yep, sure can. Just feed the amp with the left and right channel from your preamp. This will leave one input (XLR/RCA) and corrresponsing output (speaker terminals) of the RB993 free. It doesn't matter which inputs of the amp you use as long as you use the corresponding outputs for your speaker connection. I recommend leaving the centre input/output free.
This quite a powerful amp and you should have no trouble driving most speakers under normal household conditions.
This quite a powerful amp and you should have no trouble driving most speakers under normal household conditions.