As long as you're happy with the sound you're hearing - that's all that matters!

To be honest, I don't think there will be much difference between the two DACs. Your Onkyo is a highly capable machine, and I'm sure it will do a fine job converting all those digital signals to analog sound.

The only recommendation I would have is not to use coax or optical connections to output sound from the Oppo to the Onkyo, but to use the dedicated HDMI out (HDMI-2, sound only) on the Oppo. If you use coax or optical, you won't have high-resolution sound (DTS HD-MA etc.) due to the limited bandwidth of those connections. Instead you'll be stuck with the sound quality of DVD, while blu-ray did offer a significant improvement in sound as well as image over the DVD format. And that is a major difference!

Don't worry about converting anything back from analog to digital. There's no point. The actual sound you're hearing is analog, our ears are analog beasts.
Just use the HDMI audio out on the Oppo, connect it to the Onkyo and let the Onkyo do its thing. Sit back, relax and enjoy!   

Putting the cap on my initial surge into 4K UHD. I've installed and messed around with the Epson 5040UBE. It's one of those 4K Enhancement type of projectors that uses 2 layers if 2K overlaid pixels offset a tad. The good true 4K projectors are just way out of my price range.

Anyway, I'm happy with the Epson. It definitely tops my previous Epson 5020UBE in all parameters. And it has a remote controlled lens for focus, zoom and shift. The wireless works well, although the transmitter has one less HDMI port. My Sony changers and XBox look awesome upscaled directly to the projector. And since the transmitter has a direct 4K HDMI output as well, it serves to also play those devices to my TV - and it all looks amazing.

Superlatives get boring after a while, so suffice it to say that running native 4K UHD content (such as downloaded sample videos or a 4K UHD disc) directly from the Oppo is just hard to believe. The NASA stuff is literally jaw dropping (it is 4k 60 fps, and my wi-fi stutters, so I will be adding a wired internet to the Oppo soon).

So now that my budget is tapped out for awhile, I will spend time tidying up loose ends such as adding the audio cables from the Oppo to my Onkyo and adding a 4K UHD enabled switch/splitter in front of the Oppo input (or maybe behind it ..) to handle a couple of true 4K media devices (such as the Amazon 4K Fire TV box). Basically I need a way to drive both my TV and projector from the Oppo. I'm auditioning splitters now. The first two didn't work out, so I've upped the ante and bought a somewhat more expensive (4 in, 2 out) matrix switch.

Once I get this stuff paid off (or mostly), I'll start considering an upgrade to my receiver, or maybe get the Xbox S - that might be a year or more away, but who knows what the industry will do to mess up my plans by then. 

Oh, and last but not least: a shout out once again and THANKS to all who helped me think things through. I'm sure I got more bang for the buck, having good advice and suggestions. 

That's a surprise indeed!. But then again, I don't know how "(un)clean" power supply in the US is. You might try unplugging any cables running from the Onkyo to the Oppo and only leave the cinch cables from the Oppo to the Onkyo in place - see if that changes anything.

But would it be worth the hassle to sort this out? Will analog cables out of the Oppo sound better than the Oppo's audio HDMI out? I wonder. Your Onkyo has a capable DAC, too.

And I'm not sure why you would feel the need to upgrade your Onkyo at some point. It seems to be a fine machine, THX® Ultra2 Plus™ Certified and all. Or do you need Dolby Atmos?

Answers to your perfectly reasonable questions:

- My personality is such that I can't be happy with electronics that is either defective, improperly configured or poorly maintained. So if I find something that doesn't work, I am itching to fix it, even if I don't plan to use it. Especially when the equipment costs as much as I paid for it.

- The HDMI works fine, but it does waste an HDMI input port that I might need for a video device.

The other more substantive reason is that I can consolidate the audio connection to several media sources into a single input slot (say the TAPE input): Projector wireless transmitter audio via COAX, LG TV audio out via SPFIF, Oppo audio out via Mult-ichannel. Then I relabel the Onkyo "Tape" as "Media Audio" and basically leave the Onkyo set there for most all my viewing. I just have to use the Audio button on the Onkyo remote to switch to multi-channel when using the Oppo. So when using either my TV or my projector, almost all my sources will play through the same labelled port on the Onkyo.

I think I'll post a diagram one of these days. It might be interesting to get comments on it, and I expect somebody else will be motivated to share theirs as well. More fun fodder for discussion.

For some odd reason, the order in which you switch on your various machines can make a difference there. You might want to experiment a bit.

Yeah, some users of Harmony Logitech remotes have had to implement a pause for one of their machines before starting up to resolve HDMI handshake issues and the like. Perhaps that could work here as well.

Didn't know about the grounding screw on the new 205. I reckon it must be there for a purpose. Don't think it is on my (admittedly European) 105.

Quoting dee1959jay:

Quote:
Apparently Oppo has released new beta firmware which enables Dolby Vision on the player. While waiting for the first Dolby Vision UHD discs you can try Dolby Vision test files and see what they look like.

Cool. Will do. Right now, I am still messing about with a variety of HDMI switchers. I did find a reasonably priced 2 way HDMI spliter that seems to be doing the job nicely. Stable simultaneous display of the Oppo output on both my projector and HDTV (both 4K UHD). Oh, and I did attach a very robust ground strap between the Oppo and the Onkyo, so the multi-channel output is working fine. This means I donlt have to plug the audio HDMI output into the Onkyo, which I think was causing handshake issues when the Onkyo outout was selected as input to the Oppo - even though no video was attached to the audio HDMI port, I think there was a handshake feedback loop!

Dolby Vision is now available on the Oppo through official firmware.