I think you misunderstood my question, which could be my fault in how I posed it. I want my Oppo 105D hooked to the BDA-3 via HDMI. When that input is engaged on the BDA-3 I will be listening to 2-channel DSD or PCM. When that input is disengaged, I want everything to pass through to my McIntosh MX121 where the DTS or Dolby streams will be available for processing. Just clarifying that I am understanding this to be how it works.
Page 5 of the owner's manual has some info:
"HDMI Passthrough
Incoming digital video may be passed through
to another receiver such as a surround sound
processor or display using the HDMI output . The
HDMI output can only pass HDMI audio when a
non-HDMI input is actively selected. See PTHD
command in “Serial Protocol” on page 10. The
digital audio outputs mirror the inputs. No sample
rate conversion or any other processing is applied to
the output.
HDMI inputs are 1.4a compliant and can pass 4K
video at up to 30fps. HDMI input 4 is HDCP 2.2
compliant. Video is passed through to a connected
monitor at the native resolution with no processing
or conversion."