Firewire Question

[Mikey]

By default, does a Firewire DAC or Firewire Interface, slave the computer similar to Wavelength's asynchronous USB implementation?

 

My Weiss DAC2 just arrived and I believe it can be setup to slave the computer (I believe I'm using the term "Slave" correctly, where the DAC Clock controls, resulting is better jitter control). I also have an Accustic Arts DAC MKiii and PS Audio DL III I've been trying to drive from a computer with less than stellar results. When I'm looking online at Pro-Audio firewire interfaces, I'm not always sure where the clock is coming from.

 

 

 

 

 

[darascal]

I'd be interested in an answer to this one as well.

 

[barrows]

am pretty sure that the DAC2/Minerva operates as master via Firewire by default. That is the clock in the DAC2 controls the flow of data from the computer to the DAC, this is what you want for the lowest jitter.

You could always e-mail Weiss directly through the contact info on their website. They are very responsive to customer inquiries.

 

[cfmsp]

 

 

"By default, does a Firewire DAC or Firewire Interface, slave the computer similar to Wavelength's asynchronous USB implementation?"

 

Neither Asynchronous USB or Asynchronous Firewire 'slave' the computer's clock.

 

They do control the flow of data from the source (i.e. computer), but there is no clocking going on. That's why it's called asynchronous.

 

Not all Firewire is asynchronous, perhaps not even the majority is.

 

I don't have a Weiss, so I can't speak to what it does.

 

I use a highly regarded Firewire DAC which uses the internal clock to control the flow of data. This is the default setting of the DAC - called 'internal' clock.

 

This is the preferred setting for any Firewire DAC that has a high quality clock and drivers that support asynchronous flow control.

 

Most Firewire DACs are pro audio devices and will have multiple 'clock' options, including a word clock output, which can be used to feed the source computer/soundcard (provided it has a clock input). This would be beneficial in the event of AES/EBU or S/PDIF interfaces to the DAC, which most pro audio DACs also have. This feature send the clock signal from the DAC to the source, which requires a clock signal to be mixed with the data signal. This would be called 'slaving', per my understanding.

 

Hope this is helpful,

clay

 

 

 

 

 

 

[Nyal Mellor]

On the dac2 you can select the clock source. By default the master is the one inside the Weiss if connected via Firewire, but it also has the ability to slave to another source e.g. if you have connected it to a CD transport. I'm guessing the switching is automatic depending on which source is selected.

 

[bordin]

Hi Clay,

 

>use a highly regarded Firewire DAC which uses the internal clock to control the flow of data.

>This is the default setting of the DAC - called 'internal' clock.

 

A clock for async Firewire or USB transport is seperate from the master clock for the D/A operations. The latter one is called 'internal' clock, which is either 44.1K or 48K derivative, while the first one runs at a higher rate, as the top speed specified in Firewire or USB communication standard.

 

I hope I'm not mistaken about it.

 

[cfmsp]

 

Bordin,

 

My point was that there is NO separate clock being used when 'internal' clock setting is selected, as there is with other settings, which typically use clock signals from external (to the DAC) devices or certain incoming signals (AES/EBU, e.g.). The former is highly preferred to the latter, at least in my (our) DAC.

 

As to the other 'clock's, as I understand it these are derivatives of the fixed crystal oscillators - one for 44.1k & multiples & another for 48k & multiples - for purposes such as you describe.

 

clay

 

[Mikey]

I wanted to thank the folks that take the time to contribute to this forum. I purchased a Weiss Dac2 after spending much time on this site reading reviews and computer base audio discussions. I finally picked-up a 800-400 firewire cable and temporarily set up the DAC2 in my office. It's only driving a entry level Nad / PSB system, but I'm finally enjoying the music from a computer based system.

 

As-soon-as the Luxman headphone amp arrives, I'll move it to the Headphone setup as a firewire interface to an Accustic Arts Dac MK3 and Qualia010 headphones - can't wait.

 

Oh yea... and a Proton should arrive next week for the MAC Air.

 

thanks