i just got the DH520 aswell, i was looking to replace my old sony receiver outdated with no hdmi's and was also looking for it to be $300 usd or less.
i only have BB store locally or sears so i went to bb and they had this model that had the hdmi's i wanted 7.1 and all the modern codecs. i know nothing about highend receivers so just tought it was what i was looking for. the sound is good, it sounds pretty loud. i use it with samsung c7000 tv and the anynet feature from the tv orks with the receiver. making it power with the tv remote and ajusts the volume with tv remote. it also auto switches source wich is nice.
i cannot comment on sound quality because ive not heard other more expensive or similar receivers. one thing that i've noticed is hard to hear the surround effects unless they are very obvious and loud.
one issue i had but cannot replicate it is i powered everything up to watch a bluray and the screen was showing random white dots allover. i had to switch everything off and on and have not gotten that again.
the 3d enabled works perfect, ive watched a 3d movie to test it and no issues with it.
my connection is done with 1 monster hdmi 1.4 cable from tv to receiver, and bluray,pc,ps3 are pluged to receiver with monster hdmi 1.3.
should also mention this receiver does not have analog multichannel inputs. i did not notice this at the store and its a problem for me since i used those multichannel inputs on my old receiver for the PC analog sound for pc gaming. since my PC motherboard does not do DD or DTS from spdif for games, now i need to get an aditional soundcard that does DD and DTS onboard.
another problem bout not having multichannel analogs is for my backed up movies with AAC 5.1 sound on i have this on external drive i just plug to the bluray player and on the old receiver used with multichannel analog inputs. to get correct 5.1 sound. i have not tryd this yet on the new receiver but im suspecting i will no longer get 5.1 channel sound without those analogs unless this receiver somehow is able to decode the AAC correctly to 5.1?
EDIT: I just tested it and it does decode AAC 5.1 very nice.
the menu system on the receiver was confusing for the first 10 minutes after that it is a breeze to work with. every option is also described in the manual for those of us who dont keep up with the latest to read on them.
with the menu system you can adjust speaker level, speaker distance, speaker frequency wich is default of 120 for all speakers. I would like to know if I should change this frequency for speakers and how to know wich to use, it allows for different speaker configurations(location) and also has a small/large speaker option.
also has a night mode that honeslty i cannot listen to any difference between it being on and off.
also has dynamic range adjustments, off,auto,low,medium,high
you can rename your sources very easily and also allows you to select the input source connection for each source or switch between them something like that, i havent playd with that option yet.
it has a lot of sound modes to choose from for music and movies or whatever and then simple bass and treble ajdjustment.
has ARC on hdmi so the if your TV has ARC on hdmi you will get tv sound back to the receiver from the same hdmi cable that goes from the receiver wich is a nice feature for keeping cables to a minimum.
my model did NOT come with the auto tuning microphone and in the book it says only australia and i think uk models of the 520 come with the mic.
for this price there wasn't anything else that could compare in features at BB. meaning 7.1 channel and 3d capable.
oh another issue i got is where to finally place the rear speakers. since my old system was 5.1.
@tedyoh chek your setting under HDMI. i got on mine like this:
controlhdmi : on
if you select AMP+TV under audio you will get 2 channel output only so maybe that they setting u need to switch to AMP only.