Newbie question re: USB quality

The idea would be to use the s/pdif input rather than the usb.

You can use a usb to s/pdif converter, such as the m2tech Hiface ($225) or the audiophilio 1 or 2 ($550, $1,000). One of the best is the Empirical Audio Offramp, but it costs more than the Oppo.

Another option is a wireless to s/pdif converter. But they are harder to find and are usually expensive. Someone else may have a reasonable priced suggestion.

My guess is that you are going to have to pay quite a bit to do better than the Oppo usb.

You might also want to consider a device to clean up the usb signal (e.g. ifi Ipurifier, $99) or to clean up the usb power (e.g. ifi micro usb power supply ($299). Both available from Music Direct, no affiliation.

On the wireless option, the Oppo does support DLNA, which is a wireless protocol for streaming music. Your player needs to have the capability to stream to a DLNA device. I am a Windows guy, so cannot help much on DLNA with iTunes and I do not think Audivana supports DLNA. Also, I think DLNA on the Oppo only supports PCM and not DSD, although that should be confirmed.

The problems that people try to address regarding usb are jitter (timing errors), poorly formed waveforms and electrical noise from the PC. Async usb greatly helps with the timing issues, as Doogie pointed out. The timing and waveform issues are often addressed by the usb to s/pdif converters, although s/pdif has issues of its own. The wireless solution completely isolates the PC from the Oppo, so you do not have to worry about the electric issues. Some people are also concerned about RF noise effecting the usb input. The quality of the 5V signal on the usb is also an issue. I am not sure if the Oppo uses the usb 5V signal or not.

As Pkoegz says, most of these effects are second or third order once you get things set up correctly, unless you have a very highly resolving system which usually costs a lot.

Markus - AES/EBU is essentially a professional version of S/PDIF. It uses balanced cabling and XRL connectors. The OP has a Macbook Air and an Oppo. How can he use AES/EBU?