[gsawdy]

Hello Thomas,

Humm, I hadn't thought about the software that comes with the units--guess I thought it was just their virtual mixers, routers and DSP. That's good news about the software taking care of communications. So does that mean USB is to be preferred to firewire or six of one-half a dozen the other?

I was planning on running multiple instances of fb1k, each one linked to a stereo pair of outs. I doubt at most two or three rooms would be actually calling for music. Control would be via small tablet PCs and vnc. I'm not a techie so right now the learning curve is looking darn near vertical. VBG A friend suggested using softsqueeze but I'm not sure how I would link each to the outputs. I'd like it to be permenant so that I didn't have to set everything up from scratch when the computer goes down. HTH, any thoughts would be appreciated.
Best,
George

 

[thomaspf]

For the connectivity it all depends on the quality of the drivers. When you search around you can read about troubles with both Firewire and USB.

Some time back I installed a PC based multiroom system with Jriver Media Center. Their UI allows playback control for multiple independent streams.

Virtual Audio Cable also might come in handy for establishing a software patch matrix.

Cheers

Thomas

 

[gsawdy]

Quote:

Originally Posted by thomaspf /img/forum/go_quote.gif Some time back I installed a PC based multiroom system with Jriver Media Center. Their UI allows playback control for multiple independent streams. Virtual Audio Cable also might come in handy for establishing a software patch matrix. Cheers Thomas

Hi Thomas,

Do you know if Virtual Audio Cable would set up links that would be permanent? Ie, survive a rebooting? I don't want something that requires me to set it up each time the system goes down. Needs to be family friendly.

On that note, how do you like JRiverMC? What other alternatives did you consider? I've got a Squeezebox and the family gets on OK with it so I'd be really interested in any comparisons you have with that.

Thanks for the VAC idea
George

 

[seefeel]

Hey Crowbar,
Is your asynchronous USB DAC going to be for sale as a complete unit, or is it just a DIY project?

 

[nyc_paramedic]

Quote:

Originally Posted by Wavelength /img/forum/go_quote.gif Thomas, others; ... A funny thing happened in BETA1 of this code. In some OS's it would click every ounce and a while. I started looking at buffering and stuff and totally changed how it worked after I studied the way XP, Vista, OSX10.4 and 10.5 work. Too my surprise each one worked differently in ASYNC mode. I totally rewrote my flow control after looking at these. It now works much better than before. Thanks again, Gordon

What does this mean for Linux users? Do you test any of your DACs with any Linux distributions?

 

[audioengr]

Quote:

Originally Posted by Crowbar /img/forum/go_quote.gif There are probably two clock domains--the 0404's own, and the PC one, and an ASRC converting from one to the other. Indeed, this is what Benchmark does as well. The problems of ASRC are discussed on Bruno Putzeys section in the prosoundweb forums (he used to be chief engineer at Philips Digital Systems Labs for class D audio so he knows his digital). The alternatives to ASRC are: - deriving the clock from the incoming stream with a PLL and filtering the jitter down, which is what most regular DACs do, and is the worst solution with the exception of a few DACs I've read about that used fancy dual PLLs to get very good cleanup of jitter in the audio band - as above, but using a high quality digital PLL that can completely filter out jitter in the audio band; this is what the brand new ESS Sabre DAC chip does - send the DAC clock back to the source over another cable, or scrap S/PDIF and use a custom interface that accomplishes the same, and so then the incoming stream only needs to be reclocked and maybe slightly buffered; this is what a few high end DAC/transport pairs do, and a number of DIY designs - use a VCXO (adjustable clock) and a buffer and slowly (at rate below audio frequency) speed up or slow down the clock to keep the buffer from under- or over-flowing; this is what some Lavry DACs do (and others don't even though they were supposed to ) - a variation of the above with a fixed DAC clock hopefully close enough to the jittery source clock and a very deep buffer that is emptied or refilled depending on whether it's close to under- or over-flow during moments of silence in the music (such as between tracks); I have only seen one design (a DIY one) that implements this, and maybe some MSB DACs do but I can't remember and I'm too lazy to look it up, and this option suffers from latency and is unusable in cases where you need to have audio synchronized with say video, as the timing could become as much as seconds off - use an asynchronous interface, which is what these new Wavelength DACs do (and I as well, though the rest of my DAC isn't ready yet)--this is purely a digital interface with no analog timing data transmitted, and is the proper solution that should have been standardized from the beginning, instead of the misery of S/PDIF necessitating various complex and non-standard workarounds

Crowbar - there are a number of anecdotal claims on Asylum that the new Synergistic USB cable makes the Wavelength DAC's with async USB interface sound better. Have you tried this on your Async USB interface?

Computer Audio Asylum - Synergistic Research USB Cable - Mercman - February 17, 2008 at 09:42:27

 

[DefectiveAudioComponent]

Is that improvement even possible in theroy?
What is the theory behind the improvement anyway?

 

[rustbucket]

My inclination would be to let those questions die a quiet death in the interest of the very cool topic of the thread...

 

[audioengr]

Quote:

Originally Posted by rustbucket /img/forum/go_quote.gif My inclination would be to let those questions die a quiet death in the interest of the very cool topic of the thread...

Seems to me that what makes this so cool is the immunity to jitter on the USB cable.

 

[rustbucket]

Quote:

Originally Posted by audioengr /img/forum/go_quote.gif Seems to me that what makes this so cool is the immunity to jitter on the USB cable.

Without a doubt. However, the Synergy cable claims to do so by physically altering the properties of the cable (with no consideration of the transfer algorithm/strategy), while this discussion is about optimizing the method of data transfer. I don't know if the Synergy cable works or not, but it's OT to this thread.

 

[DefectiveAudioComponent]

My point was that I don't think that the cable in question can improve on a system that deals with jitter in other ways, such as async transfer.

 

[FasterThanEver]

Thomas,

Thank you for starting this thread. It collects info on some good recent developments in USB audio.

Bill

 

[Crowbar]

Quote:

Originally Posted by audioengr /img/forum/go_quote.gif Crowbar - there are a number of anecdotal claims on Asylum that the new Synergistic USB cable makes the Wavelength DAC's with async USB interface sound better.

Well, such claims are good business

Of course, the truth is not exactly simple, and the possibility for the cable to make a difference exists. Let me explain: USB Audio uses a mode that, unlike the rest of USB does _not_ use error correction, so in some systems it might be possible to get an error rate that is noticeable.

Gordon from Wavelength told me that in his final products he was getting no errors, so it's likely to be a non-issue with most setups. In my case, I thought I was getting some errors but the way I was checking turned out not robust, so I'm going to repeat this as soon as the redesign of the USB chip->DSP link is done.

 

[Crowbar]

Quote:

Originally Posted by nyc_paramedic /img/forum/go_quote.gif What does this mean for Linux users? Do you test any of your DACs with any Linux distributions?

As long as he implements USB Audio to the spec, Linux should work since Linux supports USB Audio. That's the good thing about a standard--most modern systems implement it.

 

[Crowbar]

Quote:

Originally Posted by seefeel /img/forum/go_quote.gif Hey Crowbar, Is your asynchronous USB DAC going to be for sale as a complete unit, or is it just a DIY project?

The intention is that it'll be for sale first, and then I'll see as to how to give something to the DIYers. The thing is, when you're optimizing a whole system, it can be difficult to neatly split everything into modules, and let someone get one and DIY the rest. For example, consider the interaction between the DSP and multiple DACs. However, I hope to at least allow people to buy the USB asynch module as a standalone and then build a DAC around that, but I'd only do that if there's a legal way to stop people using it in commercial equipment and only use it for DIY.
Anyway, I don't want the thread to turn commercial, so if you have other non-technical questions, use PM instead.