I am working on a project to convert my HT system to 100% digital audio up to the power amps. I am building a DSP engine (a DIY Trinnov) based on MiniDSP boards - four MiniSharcs total!
My Bluray player has a similar modification to the Lexicon MC8 shown here. This is basically what the SPDIF Oppo mod is doing. That is to bring out the digital audio streams in a standard format. I choose balanced 110ohm AES versus SPDIF or 75ohm AES-3.
The Lexicon runs 96khz internally so this mod brings out the 7.1 as four digital streams. This also bypasses the MC8 volume control but more importantly I have found Lexicon tweaks the analog VCAs to produce some of the mock surround modes. So I'll have to duplicate that function elsewhere. More on that later, I do have it nailed.
This is the AES output board. There is a large surface mount chip on the backside of that board.
Here is the modified rear panel. I have standardized on 15pin VGA connectors for 8 channel digital audio. I need 4 pairs plus grounds so that's 12 pins. This is especially helpful on the DPS engine which is in a PC chassis. You can't put an XLR connector on a PC card slot let alone four of them.
In my new setup the MC8 is no longer the audio centerpiece but just an AC3 / DTS decoder that provides additional surround modes like the famous Logic 7. The BluRay player completely goes around the MC8. The DSP engine has four 8 channel inputs of which now two will be used, the MC8 and the BluRay. The third input will someday be a 4K player.
*Note that when I say 8 channels it's really only four physical digital channels or streams because AES and SPDIF carry two channels per stream or cable.
*For you engineering types, the interface chip is an AKM4101. That is a neat 4 channel AES / SPDIF digital output formatter chip. I obviously use the hardware configuration mode hence the jumper strips on the board. Also note the transformer coupling. We're doing this right!
More images on the way.