Hopefully by the end of this month I'll have my very own DS DAC in my very impatient hands!
By digging around in the manual for my Oppo BDP-105, I discovered that it may be possible to output all audio (including SACD, amazingly enough) in PCM (LPCM) format. This is what is in the Oppo manual on page 19:
Due to bandwidth limitations, high resolution audio formats such as Dolby Digital Plus, Dolby TrueHD, DTS-HD High Resolution and DTS-HD Master Audio cannot be sent through the coaxial or optical digital audio output. A reduced resolution version of the same audio track will be output instead. To listen to high resolution audio formats in their best quality, please use the HDMI connection if you have a receiver that handles HDMI audio (see page 11) or use the multi-channel analog outputs if you do not (see page 18).
Due to copyright restrictions, SACD audio cannot be sent through the coaxial or optical digital audio output. To listen to SACDs, please use the HDMI or analog audio connections.
Due to copyright restrictions and bandwidth limitations, full resolution audio from DVD-Audio discs cannot be sent through the coaxial or optical digital audio output. To listen to DVDAudio in full resolution, please use the HDMI or analog audio connections.
On page 68 it says this:
SACD Output: Allows you to select HDMI the audio output format for SACD playback.
PCM – SACD data is converted into multi-channel, high-resolution PCM data. The converted PCM data is then output through HDMI or the internal DAC (Digital to Analog Converter) for the analog audio output ports. If you use a receiver that supports HDMI v1.1 to listen to SACD, please select this option. You may also want to select this option if you prefer the sound quality of the DSD-to-PCM conversion.
DSD (default) – SACD Direct Stream Digital (DSD) data is output over HDMI without any conversion. For the analog audio outputs, DSD data is converted into an analog signal directly by the internal DAC. If you use a receiver that supports HDMI v1.2a with DSD over HDMI, or you prefer the sound quality of straight DSD to analog, please select this option.
So here’s my question -- and I think I know the answer, alas: Can I connect the Oppo via HDMI cable to the I2S input of the DS DAC? Is it compatible in any way? If this is possible, then the DS DAC would be connected directly to my amp and the Oppo would connect via coax and HDMI, with the volume control handled by the DS DAC. The worst-case scenario would necessitate my purchase of a passive preamp of some sort. I hope I don't have to go that route, even though the well-reviewed Channel Islands VPC-3 I'm considering would not appear to alter the output at all.
Of course, when I test this, I have to listen to all types of discs. I watch classical music DVDs and Blu-rays, as well.
Another concern is my Mac Mini that, because of its (pretty much cast-in-concrete) placement in my room, cannot be connected via USB; it has to be connected via a 25-foot TOSLINK cable to where my audio rack is. That type of connection limits the output to 24/96 for all practical purposes, I guess.
I am, at Paul's suggestion, using BitPerfect with iTunes. It seems to make a difference although I have not critically analyzed it.