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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
herman
2,244 posts
 
I have a ZEN Mk3 and an Aqua DAC, and the difference between USB cables is significant to say the least.

 I am not questioning what you hear. However, it is almost impossible  to believe that an asynchronous USB DAC can't be designed to be immune from any nastiness coming in on the cable. The technology is too mature to accept that a multi-thousand  $$ DAC can't effectively handle a USB input without expensive cables. 

but in real life buffering creates latency, 
Latency is completely  a non issue in home audio. It matters not if the data stream starts now or a second from now. All that matters is proper timing once it starts. 

a clock is highly susceptible to any noise that is mixed with the signal ( and there is a lot of such noise created by the motherboard, processor, EMI etc), and this is just the beginning.

a cable on the input will not have any effect on any noise generated inside the DAC. Any competent designer can filter out any noise coming in on the cable isolating the rest of the DAC from the noise. The idea that the USB cable can be an effective filter  and the DAC input can't isn't reasonable. 

Again, I don't question what you hear, I question the design of a DAC that is affected by USB cables. 
relaks
63 posts
 
hey grandpa.. check the date on your flip phone, it is 2020
Priceless )))

relaks
63 posts
 
Any competent designer can filter out any noise coming in on the cable isolating the rest of the DAC from the noise.

This is not true, even Nuno Vitorino, the boss and designer of Innuos ZEN admits that if the transport is noisy, it is very difficult and sometimes impossible to filter the noise that is mixed with the audio signal. He openly admits that there are still a lot of unknowns and anyone who is saying the opposite simply doesn’t know what he is talking about. ( Nothing personal here ))

That is why they go to great lengths to prevent the noise occurring in the first place, by using more expensive multiple power supplies, carefully choosing processors and motherboards, trying to prevent ( ha ha) EMI pollution etc.

If that would be so easy, any laptop would be a perfect digital file transport. But what we hear is that a dedicated hi-end server like Innuos is vastly superior. It is so much better, its not even funny. Hell, I have two of their servers, an old Mini Mk 1 (which beats MacMini hands down) and a new ZEN Mk 3, and the difference in SQ is night and day.


The technology is too mature to accept that a multi-thousand $$ DAC can’t effectively handle a USB input without expensive cables.

I did not say that. What I meant was that USB cables can change the sound of a well tuned hi-end system. They "sound" differently, if you wish ))  And a multi-thousand $$ DAC simply can not employ heavy filtering, simply because it kills the sound: adds modulations etc. 
But I like your enthusiasm about new technologies ))) We will get there sooner or later.


herman
2,244 posts
 
This is not true, even Nuno Vitorino, the boss and designer of Innuos ZEN admits that if the transport is noisy, it is very difficult and sometimes impossible to filter the noise that is mixed with the audio signal.

A testimonial from Innouos about the necessity of high end servers is like a testimonial from Elon Musk about electric vehicles. I agree once you mix noise into the audio it may be impossible to eliminate, but there are no audio signals in an Innouos Zen so what is he "admitting". As far as I can see they sell only servers.. no DACS, If I was selling expensive servers, I would also argue that DACs are incapable of filtering out noise so you must buy my server to get rid of it before the signal gets there.

I have tried a pretty good variety of devices and cables listed previously to feed my DAC including a Roon Nucleus on a linear supply and Innouos Zenith MK3 with the Phoenix USB clocker as well as cables compared to my Mac Mini and $50 USB cable. I hear nothing "significantly" different or "vastly superior" about them. As I said earlier, it may be that I have wooden ears or my pro audio interface with reference, internal, re-clocking and jitter reduction handles it better than most. You can check my system and see it should be able to resolve any differences.

In any case I feel very fortunate. I’ve done the experiment so I can sit back and listen to wonderful music without fretting about what I need to do about USB cables and servers and clockers , etc. A recent extensive review on Audiophile Style lauds the superiority of a $26K server that to be optimized needs expensive power conditioning, ethernet re-clockers and ethernet cables with expensive USB cables .......

Ethernet in - USB out does not require $30K+ to optimize. I stand by my position that if your DAC is significantly and vastly improved by a server and/or cable you have a DAC problem.

I also understand the fun in trying it all and the joy (too strong?) of owning them. Have fun


And a multi-thousand $$ DAC simply can not employ heavy filtering, simply because it kills the sound: adds modulations etc.

I was very specific about where the filters are... I said 

Any competent designer can filter out any noise coming in on the cable isolating the rest of the DAC from the noise

so I’m talking about filtering and noise reduction of the incoming digital data stream, not the audio. Cleaning up the data stream will not kill the sound or all of these expensive servers and clockers would kill it too. Filtering noise from the incoming USB digital signal will not modulate anything.
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. 

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