Join Date: Feb 2007
Location: St. Paul, MN, USA
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I spent some time examining my 8.8 last night. I took the cover off, poked around a little on the inside. I happen to be an electrical engineer, but without anything to go on, I can only comment on what I saw....
Unfortunately, I didn't take any pics, but there are links to lots of pics in other threads here on AVS...
The first thing that jumps out at you is the shear heft of this beast. I think it weighs in at close to 60lbs. When you open it up you see why: there are 3 transformers - one being an enormous torroid - and a huge heat-sink that runs pretty much side-to-side across the entire width of the enclosure.
My first thought was "Wow! Receivers have come a long way in 8 years!" I have owned separates since the 90's, and the receivers I was last familiar with were poorly constructed. This one was laid-out very intelligently, and looked to have excellent engineering AND assembly, with attention to detail.
First off, that enormous torroid! I guess it could be 1.5KVA - who knows, but it was definitely MUCH larger than the 775VA torroid in my Parasound amps. The size of the torriod is directly related to the total output power capacity. This is definitely one powerful amp! I also noticed, besides the nicely twisted pair of input wires, there were a number of secondary winding outputs, 3 "high current" (large guage wire) and 2 lower current outputs - all nicely twisted and routed as far as possible from the lower signal analog circuits.
There were also 2 "square" transformers - each having several secondary outputs (again, nicely twisted). One transformer fed the front-panel (it looks like it feeds it exclusively), the other fed back toward the rest of the electronics.
The power amp was also very nicely laid out. There were separate "daughter-boards" which looked to contain the "gain" (or voltage amplification) stage of the amp, which fed the output devices - 2 large power transistors (1 each for + and - phase - likely MOSFETs) - which were attached to the heat sink with thermal "goo" (compound) between the package and the heat sink. As a reference, my 150ish W Parasound amp has 6 15 amp bipolar output transistors per channel. There were 2 main caps for the amp power rails - each 18000 uF - for a total of 36000 uF. The amount of cap has a direct influence on the dynamic headroom that an amp has. This layout suggests a common supply for every channel in the amp section. As a reference, my Parasound has a completely separate power supply for each channel, and each channel has 20,000 µF.
There are 2 fans, mounted at a 45deg angle that blow in toward the bottom of heat sink (they are under the corner mounted transformers). They look to be something like 60-90mm fans, but I didn't measure them. As a side note, I never heard them come on during my listening tests.
I looked a little at the HDMI video board and noticed that they appear to be using Si Optix chips for the HDMI outputs, in addition to the obvious Reon (that looks like it could use a simple package-top-mount low-profile Al heat sink).
The rest of the inside was pretty well hidden, and I didn't want to poke around too much. I have to say that the whole thing appears extremely well engineered AND assembled - with very good industrial design. I had heard that the amp section was top notch - now I am apt to believe it!
The last thing that I noticed was that was that there is just one convenience output (switched) on the back panel. Not a big deal, but it used to be that 3 was pretty standard. But I supposed in these days of always-on electronic devices with standby mode, it's probably not needed.
Next up - Setup!