Why is USB frowned upon?

[bored184]

Depending on what I read it appears USB is frowned upon as a audio cable interconnect between DAC and source. I don't want to start a heated argument, especially the brand of cable, but what makes it inferior to say optical or digital coax? I am looking at getting a new DAC either a Schiit Modi 2 Uber or maybe, there is a very slim chance, the Maverick Audio D2. I pretty much use USB because I either use my laptops or Raspberry PI connected to my server. I know HiFi Berry makes the linked outboard but I don't have any knowledge about it. Currently I own an older DacMagic Upsambling DAC and a Emotiva XDA - 2. The Emotiva I will be loaned to a friend for a while and I want to get a new DAC to take advantages of the the higher sampling rates the new DACs can handle through USB.

 

[woofmytweets]

it's not the same thing, really. if you connect your DAC with a USB, it becomes an external sound card, so you have to install drivers, and it becomes a Windows (presumably) device. if you connect via optical or coax, its a 1-way connection, and your PC's internal sound card sends it a bitstream....which is better? I've used both and had nothing bad to say about either setup.

 

[Condorsat]

I found the The Hans Beekhuyzen Channel to be helpful. I just take his advice & roll with it.
About 1139 time in this Youtube video ... he talks about USB.

Currently I'm using HP Laptop (USB output) >Audioquest Jitterbug> Schiit Audio Uber 2
Also using an optical out of Dish Hopper > Schiit Audio Uber 2 (multiple selectable inputs)

 

[BigElCat]

I watched the HB video. I've heard from multiple sources that Windows 10 dumped Windows Media Player. My copy of Windows 10 Pro came with WMP. It even has FLAC, a first for Microsoft.

In my system, the USB interface sounds as good as either of the SPDIF formats.

 

[rolltide]

Here are my thoughts on why USB is frowned upon -

- It is said that early implementations of USB didn't sound very good. I've never personally experienced this, but its probably a fair point.

- Because Microsoft refuses to put native support for USB Class 2 audio, Windows users are required to install drivers if they want to exceed 96/24 resolution. This requires companies to develop drivers and provide support to customers. As this creates issues, many products limit the USB to 96/24, which gives the impression USB is compromised somehow over the alternatives

- The "audiophile tweak industry" has created a lot of anxiety around USB by claiming it has terrible, terrible problems that you need their tweaks to fix. This has led to a general mood of "well gosh, if I need to buy an expensive USB cable and attach various anti-jitter devices to it to sound 'right', I'm probably better off just avoiding it". I've never had a single problem with any USB DAC; out of good form I'll add YMMV.

 

[Njoy-Music]

All I can say is my experience. USB as implemented in many systems is less than stable. It can be hampered by the stability of the power, other resource usage, overloading of the bus, etc. What many of those external widgets attempt to do is stabilize it enough to maintain correct timing to the output device. And some of the buffering required by the DAC's is to allow them time to put together a stabilized package that can be sent to the DAC for processing. While my new motherboard offers a substantially improved USB system internally, it was seriously hampered by an internal network card that impacted it's performance horribly. There can be any number of other devices sharing a USB bus that also impact it's performance. Early on USB was slow enough it could barely handle it all. With newer implementations that is not an issue any longer but the power and signal clocking can still be impaired by either Windows itself, other drivers or a poor power supply. I think it's come a long way and when done right can sound amazing. Early on yes there were issues. But from what I see it's getting much better and a serious contender for premium sound.

 

[nj pheonix]

I never had an issue using usb.

 

[JoeESP9]

The XDA-2 does 24/96 via USB. USB works just fine for any of the three USB DAC's I own.

 

[Smallies]

http://www.head-fi.org/t/701900/schiit-happened-the-story-of-the-worlds-most-improbable-start-up/690

 

[lini]

bored: One of the main disadvantage would seem to be that the USB connection typically isn't galvanically isolated/decoupled, whereas optical SPDIF is by principle and electrical (aka coaxial) SPDIF often is due to transformer coupling - and in addition computers most often are safety class I devices and hence are connected to safety ground. Hence there's a higher chance for hum and noise problems with USB compared to SPDIF.

Greetings from Munich!

Manfred / lini

 

[sKiZo]

Maybe your grandpa had issues with USB, but the tech has improved immensely over time.

Couple points ...

- USB only requires a driver IF the DAC requires it. That's a designer decision.
- Being a WindOHs! device was problematic with DirectSound (or mfg drivers), but not so with WASAPI
- S/PDIF (coaxial and optical) have their own associated issues. The standard is ancient and how it performs is completely up to whether whoever built your motherboard took the time to RTFM ...

My computer has Realtek sound, which suffers severe suckage, so that rules out both optical and coaxial. The built in USB support ain't all that great either. Biggest problem still facing USB is RF noise inside the computer itself - I know mine had some serious interference due to the wireless mouse and keyboard. Solution there was to install an add on card that created it's own USB channel and draws power directly from the power supply instead of the system buss. Good shielding on the card itself and complete isolation from the standard channels = Not a peep since.

A couple high end sound cards also were epic fails IMHO. Asus Xonar and E-Mu both get good reviews, but both hit the drawer of doom shortly due to inconsistent performance and lockups ...

And yes, I did have latency issues on ALL inputs to the DAC with XP Pro due to DirectSound. Not a stumble or stutter since upgrading to W8 and turning sound handling over to WASAPI, which is the next best thing to bit perfect and requires no additional drivers.

Lots depends on the DAC too. Mine has the Tenor chipset which really sings here. I also went a step further and changed out the $20 USB add on card I'd originally used for an "audiophile grade" card that runs rings around anything else I've tried.

The inter-relatedness of all things .... oooohhhhhhhmmmmmmm ...

PS ... my DAC tops out at 96/24 on USB, and 192/24 on S/PDIF, yet the USB connection far outshines the others for overall sound quality. It's not all about the bits, eh.

 

[RichPA]

Early implementations of USB inputs on DACs were indeed inferior. For example, I have a Bel Canto DAC 3.3VB, a pretty well respected high-end DAC from a few years ago, and it does not sound good through its USB input. I used a SOtM USB-to-s/pdif interface, and it sounded much better. In some implementations, USB also seems to be subject to radiated RF noise, which can affect some components more than others. My sense is that USB interfaces have become much better over the last few years.

 

[Hipocrates]

Another example for early implementations.
My audiolab M-DAC stinks with usb, but if I use an Ulink from Bel Canto is totally different. That been said, my M2tech hiface, despite it's cheap feeling works pretty good.

 

[SoNic67]

First let's be clear: Unlike data transfers, the human ear doesn't have a "buffer". It means that the stream of "data" needs to be continuous and with a constant speed.
The USB transport was designed with the idea that you can send "packets" of data at higher speed to the connected device and this device will store that data and eventually distribute it as needed.

That's why any implementation of USB DAC that didn't provide for asynchronous transfer (or a huge RAM buffer) is just flawed from the design. Every device connected to the PC on the USB would compete for the internal hub "attention" and that's not good for audio. Lots of early devices didn't use that mode because... it's complicated to program, requires specialized drivers. Some cheap adapter had only one clock, so the 44.1kHz was upsampled internally to 48kHz with sucky results while 88.2 and 176.4 rates where just left out of this.
Sure, USB receivers has FIFO buffers inside you will say. Well, those are not sized for Audio, just for jitter attenuation and they will fall short. Unless the receiver has a generous RAM buffer, it won't be of too much help.

BUT with asynchronous USB, you NEED to have a dedicated (second) USB hub in the PC, just to connect the DAC (and only the DAC) to it. And that hub has to support asynchronous USB method of communication.
I am not talking about the ports here, I am talking about the chip that those USB ports are connected to internally.
Why? Because it makes absolutelly no sense that the whole PC USB peripherals to be synchronized with your DAC (another peripheral device). You don't want your USB-connected mouse, keyboard, printer, memory stick or even back-up HDD to wait for the DAC "approval" to communicate with the CPU.
Stuff gets even more complicated when you try to play video with that audio async USB. Now your video has to be synchronized with the DAC sampling rate! Can your video player do that correctly? Doubtful, probably will just drop frames to match the audio .

For people that are more "technologically curious", this is a good read:
http://www.edn.com/design/consumer/...-with-care--Scary-stories-from-the-test-bench

 

[bored184]

Thank you for all your input! If I understand all of the input above correctly, the early days of USB audio was not so great but as technology improved USB has become a viable option. Maybe not as easy to setup like optical or digital coax but with a little tweaking it can yield excellent results.

Correct?

 

[SWL3600]

I use USB to Optical with excellent results!

 

[BigElCat]

Thank you for all your input! If I understand all of the input above correctly, the early days of USB audio was not so great but as technology improved USB has become a viable option. Maybe not as easy to setup like optical or digital coax but with a little tweaking it can yield excellent results.

Correct?

Several of us are saying, "Embrace USB, no fear, bro". It's plug'n'play. If you don't like, upgrades can be made. USB is as easy as the other two,

 

[BigElCat]

Shout to SoNic67:

I have this, some say it's not true asynchronous, that the advert is deceptive.
http://www.amazon.com/Music-Hall-Digital-Audio-Converter/dp/B002NZV7X4

Then I have this;
http://ppaproduct.blogspot.tw/2013/07/audio-grade-usb-30-pcie-card.html

I'm true asynchronous now, with the Paul Pang. Is this correct?

I have a nice cable between the two, FWIW.

 

[rwartner]

My Maverick DAC D1 will take the various inputs. One issue is that if you want to do optical or coax then you need that output from your computer and it may not come with it. So you may need a USB to Optical converter. I did this with Nuforce U192S. It works fine although I don't think they make them anymore.

When I went to Windows 10 I decided to try USB. Works fine. I don't think there is difference. My music is all lossless CDs, no hirez.
I like BigElCat's reply that you can always upgrade. I can always add back the optical converter.

 

[prighello]

USB is not frowned upon. Where are your sources?