I have had the amp for over a year now but there is something I just can't figure out! When I have the amp set to direct stereo the display starts to dim after about 3 seconds. When something is changed on the amp the display somes up to its "set" brightness and dims again. This does not happen on any other surround option. This does not bother me but I would like to know why is this and if I can use it on other surround settings. I can not find any info in the manual or through the amps menus. Is this normal???