Hi brucew5828,
This is Darth Vader and I just have a few questions for you:
Do you enjoy having a large and heavy HT receiver?
Do you appreciate HT receivers that tend to operate on the warm-hot side which is a major reason for internal electronic part failures, reduced life span and the need for large heat sinks?
Do you enjoy higher noise levels (lower Signal-to Noise Ratios)?
Do you prefer smaller Dynamic Ranges (reduced ability to go quickly from soft to loud)?
Do you prefer higher distortion levels?
Do you get a thrill out of wasting electricity and paying higher electric bills every month?,
If you answered 'YES' to the majority of these questions, you are an ideal candidate for class A/B amplification in your HT receiver.
If you answered 'NO' to the majority of these questions, however, you may want to consider joining me on the "Dark Side". Of course, this will require you to think logically, not emotionally, eliminate irrational avoidance of class D amplification, keep an open mind and let your ears decide about your HT receiver choice.
I run separate amps directly from an Oppo-105 to my amps and do not use a HT receiver or external surround sound processor for a 5.1 system. I would suggest you may want to do the same for your setup since a HT receiver or processor is redundant and not necessary if you're already incorporating the excellent Oppo-105 in your system.
Unless you think there are significant benefits from room correction or bass management software often built into the newer HT receivers and processors, which I think there are not, there is really no reason to insert the extra component in your system.
A few years ago before buyiing the Oppo,, I used a DVD player routed through an expensive 5.1 surround processor. I used 3 class A/B amps to drive all 5 channels. Once I upgraded to the Blu-Ray Oppo and understood its full capabilities , I first sold my processor and ran its outputs directly to my amps. There was no detectable reduction in performance and I ran my system this way for about a year.
About a year ago, I decided to replace all 3 class A/B amps with class D amps ( D-Sonic mono-blocks replaced an Aragon for the main l+r, Emerald Physics bridged stereo amp replaced an Adcom for the center and a ClassDAudio stereo amp replaced another Adcom for the rears). I immediately noticed a definite improvement in the performance of my 5.1 system. The main improvements in the sound were the extremely low noise floor (sounds emerged from a dead-silent background), increased dynamics (the ability to go from soft to loud on all channels was obviously better and, at times, even startling).
Other benefits included affordabiliy, smaller size, reduced weight, average reduction in my monthly electric bill of about $40 and none of the class D amps get hotter than luke-warm no matter how hard they're driven.
Hope this was useful to you,
Tim