Newbie question re: USB quality

Scott

I think we need to make a distinction between USB Hosts and USB Clients.

A Host provides the "control" and is the master device controlling a USB Client.

To put it in simpler terms when you hook a PC to a printer using a USB cable - the PC is the USB host while the printer is a USB Client. The PC uses what's known as a USB Type A connector - signifying its role as a Host and the printer uses a USB Type B connector - used for USB Clients.

The USB problems we often talk about involve using the PC as the device controlling a DAC. The PC isn't a particularly good clock master and first generation USB-SPDIF devices/interfaces - ran in synchronous modes which sounded terrible. This has been addressed in a large part by asynchronous USB interfaces where the clock control is no longer in the hands of the PC.

Even then, you will find some USB-SPDIF devices perform better than others.

On the Oppo, this involves using the "SQUARE" Type B USB port on the back.

The Oppo is quite unique because it is also a media player (and CD/SACD/BDP etc). A media player is fundamentally a custom computer designed to playback media files. As such, you will also find Type A (flat/rectangular) USB ports on the Oppo. This allows the Oppo to work as a USB host controlling a USB device like a thumb drive.

In such a use case, the Oppo merely reads the DSD/PCM files on the USB drive and plays it back accordingly. There is no PC involved.

If you have a properly set up USB dac and a reasonably well set up USB server, you are fine. I have tried many if not all mentioned options on this site. I do have a sotm td-USBexp out with battery power supply but the difference is minor at best. Concentrate on down stream. My view at this point is that speakers and their set up make the biggest difference. Vinyl still RULES but HD digital has never sounded been better.

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.

HELLO!
What about AES/EBU I have found it far superior in my set up to any USB that I started with

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?