HI, I am newbie here in this forum. I need advice on my marantz sr4200. I brought it about 1 month ago after some research on web. I have no problem playing DVD in DTS mode. However, when a DVD is play in DD 5.1 or swithing to DD 5.1 from DTS, there isn't any audio output from the speakers. I tried at least 5 DVDs but the result is same. At first I thought it my speakers but it isn't because it is fine when i listen to tuner. I went throught speaker setup, manually tune the function nob at receiver to DD but no luck. I really couldn't figure it out why. There isn't much detailed info on manual. I tried going back to the shop but they aren't helpful either. Did I missed out certain steps/setting? Also, I noticed that there is a huge difference in audio level output between DVD (-5 dB - 0 dB) , Audio CD(-25 dB), Tuner (-25 dB) to get equally loud of sound. Is it normally the case for a marantz amp? My DVD player is Toshiba SD1300 connecting to Marantz via optical output. Any informative help is appreciated. Thanks. Thank you.