Streamer output options

Per one cable manufacturer regarding history of digital cables: 

Before USB, there was Coaxial (S/PDIF) digital. This suffers from the technical problem that the clock must be recovered from the data stream, a technique that produces more jitter than desirable. Then came asynchronous USB, where the DAC controls the data rate, so a high-quality, low-jitter clock can be used in the DAC. This was technically a better solution, and it should sound perfect.

But it didn’t.

In fact, it sounded worse than using a Coaxial cable connection. Some blamed noise on the 5V line. Others blamed noise on the ground line. Various techniques were used (in an effort to offset the sound degradation), in the form of add-on boxes and dongles; galvanic isolation, regeneration, and noise filtering. These often gave some improvement but at a high cost; they also often left their own footprints on the music.

So, in 2018, we designed the original Black Magic USB cable.

We found the real problem is not noise on the ground or 5V lines—it’s noise that piggybacks on the data itself. Black Magic uses innovative techniques to reduce and absorb this noise, as well as special measures to prevent its radiation from the cable.

In 2022, we revised the whole cable, producing the USB ULTRA cable. This performs at an entirely new level from the original.

In 2023, we pulled out all the stops and produced the USB GOLD version. This uses selected silver/gold wire and a different kind of mechanical damping.

And in 2024, we have a new design: Prime – our best yet.

Implementation of interfaces needs to be taken on a case by case basis. How can anyone state categorically any single interface is the best. Usb optimization varies greatly across both streamers and dacs. I2S not offered on a great number of streamers so DDC's employed, optimization of this output varies with these, for dacs since this native signal path, less variability here except with quality of internal clock.

One would have to actually optimize and implement these interfaces in their own setups to determine superiority. I've tried any number of usb optimizations over the years, this with variety of streamers and dacs, with present setup I2S provides superior sound quality vs usb, this with both my Musetec DH-DA006 (sabre chip) and Laiv Harmony (R2R).  Musetec has one of the most sophisticated usb boards I've seen, Laiv middle of road.

15 to 20 years ago USB was not a great choice for audio but it has come a long way since then.

If you’re running usb out of a computer there’s a possibility that power might be running through also and that can add a bunch of noise, but if you’re running out of a streamer that’s set up for using usb as it’s preferred output like Aurender, the signal will be a lot cleaner before it hits the DAC.

@mclinnguy "noise that piggybacks on the data itself" 

Somebody is going to have to explain that one to me. 

USB-Audio uses isochronous, interrupt, and control transfer. Characteristics of the Interrupt Transfer mode are:

• Guaranteed Latency
• Unidirectional Stream Pipe
• Error detection and next period retry.

USB has error control and management. Any 'noise that piggybacks on the data' to be relevant (audible) would have to modify and corrupt the bitstream. That would cause a checksum error and have the effect of triggering the error correction. Then, a retransmit would occur of uncorrupted data. The concept of 'noise that piggybacks on the data' causing audible issues is not possible with USB data and simply not applicable.

Anything and everything you hear from a streaming source is derived from the bitstream. RF noise, at frequencies thousands of times higher than human hearing is taken care of by the reconstruction filter of the DAC. Any audio band noise measurable after that point on is from the analog section of the DAC, downstream line amp, or power amp, and likely due to improper gain staging.