seethroughyou wrote:

Sadly, Oppo discontinued and the only odd rare Oppo used turns up at silly money and can’t vouch if it works or not as sold over EBay.

I have a 7.0.0 surround sound system using (2) BL 5, (1) BL 7.4, and (4) BL3.  I have not yet gotten into ATMOS.

I do not use a B & O preamp.  To the best of my knowledge, there is not a B & O system that has an easy setup for accounting for speaker placement and distance from listener.

I advise getting a preamp/processor that has Audyssey or similar means for adjusting the levels and frequency response for the various speakers.  My preamp is old (Integra DHC 80.3).  With this preamp is a microphone with long cord that plugs into the preamp.  Then, through on-screen menus, the user can make some general speaker selections.  Depending on the preamp, there can be one or several microphone locations that the preamp can take measurements from.  I locate the microphone at the top of the seat backs of the chairs.

The preamp will then emit signals to each speaker in turn while measuring the tested speaker's response.  After all testing has been completed, the preamp will adjust frequency response, delay times, and levels for each speaker.

I arranged my speakers as suggested by Dolby Labs.  I also built stands for the smaller speakers so their tweeter heights match the BL5s.  I have an acoustically transparent video screen so even the BL7.4 is at the appropriate height as the BL5.  All three speakers are behind the screen.

For disc players, I recommend getting a "universal" player.  Such a player will play CDs, DVDs, DVD-As, and SACDs.  My player is even more universal in that it will play PAL and NTSC video formats and is region free.