Newbie question re: USB quality


Thanks to everyone who has guided me to this point that I'm able to even ask this question! I'm learning quickly about computer audio and right now using a USB thumb drive with DSD files plugged into an OPPO 105 (non-Darbee edition). I'm getting good quality sound that is certainly superior to rebook CDs.

However, I've seen it mentioned in various articles on audio websites that USB as the interface has various weaknesses. Usually, this is just stated without any mention of other options. What other ways would I be able to get audio files to my Oppo. I have a Macbook Air, but other than connection via USB from the computer, I don't know if any other way to get files to the Oppo.

Again, I appreciate your willingness to help a technophobic newbie.

Best,
Scott
smrex13
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.
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.