USB audio coming of age?

[john dolan]

Can he be used as a remote control to play records I wonder.

 

[ItemAudio]

It can do anything: deus intra machina.

 

[Julf]

Can he be used as a remote control to play records I wonder.

How do you feel about Ukrainian accordion music?

 

[Peter Stockwell]

It can do anything: deus intra machina.

That's a bit Greeky, innit ?

 

[jirij]

What I find difficult to understand is why anybody bothers with any other transfer protocol other than TCP/IP.

I have put this question to the forum on a few occasions, and never received an answer, let alone a satisfactory one.

Chris

(in case this is still relevant)

Well, TCP/IP is a family of L3/L4 protocols (ISO/OSI), so I presume the question was related to TCP/IP over Ethernet using RJ-45 connectors and cat5 (or better) cables.
One thing that comes to mind is - standards, resulting in user convenience. USB had support for audio streaming using isochronous URBs for a long time, since 1998 in fact (link) - including the famous "asynchronous" (feedback) mode. (Note that the document doesn't contain "Gordon Rankin" anywhere.)
This spec got implemented in major OSes (Windows, Mac, Linux, ...) eventually, which meant (for DAC manufacturers) that it was rather easy to create an USB-based interface that would "just work" for anyone, in the same fashion and using the same software layers like integrated sound cards or (at the time) PCI or ISA sound cards, meaning automatic compatibility with any software player, any application (games, movie editing software, professional audio software, ...).

Couple that with the convenience of USB (desktop, laptops, ..., easy to install for the common Joe, unlike PCI cards) and there you go - the popularity of general USB might have been the driving force behind it.

Why not TCP/IP or Ethernet? Perhaps because there's no standard way of using it like USB or PCI (making the DAC appear as sound card on a computer), perhaps because it's complex by design (IP addresses, routing, DHCP, ...) and you need to complicate it further in order to simplify it using methods that don't always work reliably (automatic broadcast device discovery). Even if you get past the basics (working network), you still need to solve the audio playback problem - you could use DLNA, but that's optimizing for one specific use case (iPad/Android + NAS + networked DAC + switch or router). Even if you choose to connect it directly to a PC and run the DLNA server and controller as software applications, you still need application support (which is going to be lacking in anything that isn't an audiophile music player) and a free Ethernet port on the computer, which can be a problem (compare 1-2 RJ-45 sockets with 6-10 USB sockets on a common desktop motherboard, 0-1 RJ-45 with 2-5 USB on a common laptop).

USB just hit the sweet spot between "it's rather easy to implement on embedded devices" and "it's convenient for the user". That doesn't mean network streaming won't prevail in the future, I can easily imagine WiFi or Bluetooth-enabled DACs (even though they could suffer from RF noise), but for now, fortunately or unfortunately, USB rules the world (as FireWire pretty much died out, which is a shame).

Simply put - thanks to the versatility provided by USB, I can enjoy decent sound reproduction (Audiolab MDAC) when playing Mario with a friend on a Nintendo emulator running on my desktop, connected via HDMI to a TV, using generic USB or Bluetooth gamepads.

 

[ItemAudio]

Getting back on topic - on the XXHighEnd forum over the last six months, there has been a little flurry of interesting activity re: modifying PCIe cards for USB. In particular the Silverstone card has received attention. Perhaps someone could spare £9.50 for a trial? Does it sound the same as your motherboard output?

 

[tonerei]

Sat on the fence re this but intend getting the ppang had to stop spending. Heard a couple of transports with the PPA card and seems to be an improvement on my pc.Mind you they also had better power supply implementation with no pico. There is some experimentation going on trying to do what you suggest above Mark. Clock,power on a pcie card. Cheaper version of PPang if you can get it to work. Is this ready to go just install ?

 

[ItemAudio]

Hmmm. Would be interesting to compare the motherboard output of the Gigabyte board - which is probably the best 'free' USB currently available - with the best of the 'nearly free' unmodified USB cards.

The PPA card is a nice stop-gap between these and the SoTM and JCAT, but there's so much room here to experiment. This is another useful little tool in the armoury:
http://www.overclockers.co.uk/showproduct.php?prodid=CB-106-OK

Getting the PPA onto clean power isn't too tricky and definitely a good idea.

 

[suzywong]

Getting back on topic - on the XXHighEnd forum over the last six months, there has been a little flurry of interesting activity re: modifying PCIe cards for USB. In particular the Silverstone card has received attention. Perhaps someone could spare £9.50 for a trial? Does it sound the same as your motherboard output?

And where, pray, can I find one of these for £9.50? £17 is the cheapest I've found so far.

 

[ItemAudio]

A locally generated clock (like the one in a DAC with the input buffer scheme as described) of course can be contaminated with (asynchronous) signals. Such a sampling clock has to be considered to be an analog signal and thus is prone to all kinds of "contamination mechanisms". But it is simpler to keep a locally generated clock clean than to regenerate a low jitter clock from a jittery input clock.

Same with DACs with an async USB interface. The async scheme is a good idea, but it has to be properly implemented.

Daniel

Daniel: Can I get your response to the fact that a significant number of owners find your DACs not to be impervious?

I've personally heard at least three Weiss Firewire DACs in customers' homes that the customer believed clearly discriminated between Firewire sources. We've sold several Mac Minis and many Firewire cables to customers after extended home loans who are convinced they make their DAC sound better.

Rafael Todes chose Weiss DACs specifically in his review of SPDIF converters, and was able to map audible differences between them. Later, he used the same converter to review differences between Firewire cables and computers.

In the Antipodes audio link referred to above, there are several users talking about differences between sources into the Weiss. I could go on . . . but you get the picture!

Clearly one of the design goals of a DAC is to level such differences as far as possible, but many designers (like John Westlake) are sanguine about the difficulty of making universal predictions in this area - while not being unaware of the possibility that users are simply kidding themselves. Other actively embrace the idea that the transport and digital cabling may well play an active role in the performance of the source, however the DAC is designed. And your product range seems to speak volubly in support of that idea - with some very thoroughly engineered - and expensive - digital transports and cables.

But how do you respond to customers who do not find their Weiss DACs to be immune to upstream factors? The customer is always right? Or not?

As you may know, I take the view that a DAC being susceptible in this way is absolutely no discredit to it. However, you should be warned that some on this forum will view such an admission as a confession of failure. And a rather strict interpretation of 'bits are bits' is proselytised by some Weiss dealers in the UK.

 

[maxflinn]

Daniel: Can I get your response to the fact that a significant number of owners find your DACs not to be impervious?

Subjectively? Any measurements or were ABX tests done?

I've personally heard at least three Weiss Firewire DACs in customers' homes that the customer believed clearly discriminated between Firewire sources. We've sold several Mac Minis and many Firewire cables to customers after extended home loans who are convinced they make their DAC sound better.

Subjectively? Any measurements or were ABX tests done?

Rafael Todes chose Weiss DACs specifically in his review of SPDIF converters, and was able to map audible differences between them. Later, he used the same converter to review differences between Firewire cables and computers.

Subjectively? Any measurements or were ABX tests done?

In the Antipodes audio link referred to above, there are several users talking about differences between sources into the Weiss. I could go on . . . but you get the picture!

Talking? Subjectively? Any measurements or were ABX tests done?

Clearly one of the design goals of a DAC is to level such differences as far as possible, but many designers (like John Westlake) are sanguine about the difficulty of making universal predictions in this area - while not being unaware of the possibility that users are simply kidding themselves. Other actively embrace the idea that the transport and digital cabling may well play an active role in the performance of the source, however the DAC is designed

Any evidence, or are you talking subjectively/speculating again?

And your product range seems to speak volubly in support of that idea - with some very thoroughly engineered - and expensive - digital transports and cables.

Do you mean subjective opinions speak volubly in support of that idea?

But how do you respond to customers who do not find their Weiss DACs to be immune to upstream factors? The customer is always right? Or not?

Find how, by measuring, or subjectively?

As you may know, I take the view that a DAC being susceptible in this way is absolutely no discredit to it. However, you should be warned that some on this forum will view such an admission as a confession of failure. And a rather strict interpretation of 'bits are bits' is proselytised by some Weiss dealers in the UK.

Mark, I doubt Daniel knows anything about you and I can't see why you should be warning him about anything, especially as all the 'evidence' you've put forward amounts to nothing but speculation based on subjective listening.

Daniel's products measure the best because of solid engineering principles, not subjective listening or speculation.

 

[Tony L]

<moderating>

I'll kill this one as it seems to have degenerated too far into the usual entrenched and cyclic agendas, trolling, shilling, FUD etc.