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USB sucks

USB really isn‘t the right connection between DAC and Server: depending on cables used, you get very different sound quality if the server manages to recognise the DAC at all. Some time ago I replaced my highly tuned Mac Mini (by now-defunct Mach2mini, running Puremusic via USB) with an Innuos Zenith Mk3. For starters I couldn‘t get the DAC (Antelope Zodiac Gold) and server to recognise each other, transmission from the server under USB2.0 wasn‘t possible because the server is Linux based (mind, both alledgedly support the USB2.0 standard) and when I finally got them to talk to each other (by using Artisansilvercables (pure silver) the sound quality was ho-hum. While I understand the conceptual attraction to have the master clock near the converter under asynchronous USB, the connection‘s vagaries (need for exact 90 Ohms impedance, proneness to IFR interference, need to properly shield the 5v power line, short cable runs) makes one wonder, why one wouldn‘t do better to update I2S or S/PDIF or at the higher end use AES/EBU. After more than 20 years of digital playback, the wide variety of outcomes from minor changes seems unacceptable.

Since then and after a lot of playing around I have replaced the silver cables by Uptone USPCB rigid connectors, inserted an Intona Isolator 2.0 and Schiit EITR converting USB to S/PDIF. Connection to the DAC is via Acoustic Revive DSIX powered by a Kingrex LPS.

The amount of back and forth to make all this work is mindboggling, depending on choice of USB cables (with and without separate 5V connection, short, thick and God-knows what else) is hard to believe for something called a standard interface and the differences in sound quality make any review of USB products arbitrary verging on meaningless.

Obviously S/PDIF gives you no native PCM or DSD but, hey, most recordings still are redbook, anyway.
Conversely it is plug and play although quality of the cable still matters but finally it got me the sound quality I was looking for. It may not be the future but nor should USB, given all the shortcomings. Why is the industry promoting a standard that clearly isn‘t fit for purpose?

Finally, I invite the Bits-are-bits naysayers to go on a similar journey, it just might prove to be educational.
antigrunge2
djones51
4,947 posts
 
If you're having problems try a Benchmark DAC3.


Benchmark's USB system supports USB Audio 2.0, DSD, and USB Audio 1.1. It is frequency agile, and will follow sample rate changes initiated by the computer and/or the media playback software. In all modes the USB communications are asynchronous in order to eliminate unnecessary sources of jitter.

The DAC3 has a low-jitter master clock which controls the transfer of audio data from the computer to the USB sub-system. The computer asynchronously transfers audio data to a buffer in the DAC3. The contents of the buffer are then asynchronously transferred to the D/A conversion subsystem. This second asynchronous transfer eliminates any traces of jitter that accumulate as the data is transferred between the USB and conversion subsystems. No traces of jitter-induced distortion are measurable to our measurement limits (better than -150 dBFS). This truly represents the state-of-the art. Enjoy the convenience of computer playback without compromise. The Asynchronous USB system supports USB Audio 2.0 for high-resolution 192kHz, and DSD playback. 

coltrane1's avatar
coltrane1
685 posts
 
So, the OP is saying that the USB connection I have via an iMac computer and a PS Audio sucks, and I should spend a gazillion dollars in an attempt to upgrade the sound?  No thanks, my USB connection is perfect. And the sound is just marvelous. But nice try!
chesebert
67 posts
 
The optimal way to play a digital file has already been found over a decade ago - DLNA enabled or other network enabled streamer with built in DAC. This is essentially a CDP for the modern era. One box fully integrated and optimized solution without dicking around with connectors, wires, connection formats and multitude of other “options” that do nothing but degrade/change sound. 
Post removed 
rixthetrick's avatar
rixthetrick
1,060 posts
 
@lgldsr73 - There's got to be a better way for sure.
If audiophilia were more of a priority for engineers, we might already have it?

I've been present when USB (using a high end USB cable), toslink, and coaxial cables (even high end contenders) have all been put to the test - USB had won. Mind you this was a couple of years ago now, and I acknowledge things change rapidly in our hobby.

There's AES3 aka AES/EBU which looks promising to me, though I haven't tried it personally.

I am disappointed that digital hasn't yet universally beaten the older methods of analogue recording and retrieval. With constant advancement, and new data transfer protocols, newer technologies in processing the digital format to analogue - I hope one day it will.

As I believe camera technology has surpassed film finally. Hasselblad H6D-400C, PhaseOne XF IQ4, Fujifilm GFX 100 are high end examples of this, where digital finally is better than analogue.

What do you think is the best at the moment? What are you using?

Rick
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