Firewire to SPDIF

I suspect that your question is mis-phrased, and you are referring to converting digital audio data carried via firewire or usb to analog audio, not to SPDIF. SPDIF is digital, and like firewire and usb is a means of transferring digital audio from a computer to a compatible dac or other device.

Also, many computers have SPDIF outputs, and if they do not, and it is a desktop computer, an inexpensive sound card with a SPDIF output can be easily added.

But to answer what I believe is your real question, whether or not usb can be counted on to consistently convey 24/96 digital audio to a dac, without intermittent breakup, it would be dependent on the computer. Quoting from myself in this recent thread:

It would be computer-dependent. USB relies significantly on processing by the cpu and its associated chipset on the motherboard. I would expect that a modern well-tuned computer with adequate memory will have no problems, but a computer which is bloated (as many are) with large numbers of useless background processes, and is configured with too little memory to support them optimally, and/or is running resource-hogging Vista, or is old and does not have typical contemporary computing horsepower, will have problems.

Firewire, in contrast, shifts most of the processing associated with the interface to the interface chip itself, and guarantees that the data rate will never fall below a certain amount (which was chosen to assure that the DV format (Digital Video, for which the data rate is much higher than for audio) could be transferred without interruption).

That thread does not address having the audio files on an external usb hard drive, which obviously would increase the possibility that problems could arise sending data to a dac via usb with a marginal computer (since the computer would have to simultaneously support inputting the data from one usb port and outputting it to another). Perhaps others will comment on whether they have done that successfully, including a description of their computer.

Hope that helps,
-- Al

My Benchmark DAC-1 instruction manual clearly says that it utilizes USB 1.1 protocol, and is compatible with both USB 1.1 and USB 2.0 ports. USB 1.1 is the first widely used and bug fixed version of USB 1.0. It has a maximum data rate of 12Mbs (full speed), more than enough to pass 24/96 signal.

USB 1.1 still no where as fast as Firewire. USB still utilizes the CPU in your configuration and transmits packets, not data streams.

Both of these statements are correct. But as confirmed by several posters in the thread I linked to above, 24/96 can be successfully and consistently transferred between a computer's usb 2.0 or 1.1 output and a dac that has a usb 1.1 input. Although, as I said, a computer which is underpowered or software-bloated may have problems doing that.

Re converting firewire or usb to spdif, yes that may be necessary for specialized or professional applications, but if you want to send spdif from a computer to a dac, why not output spdif from the computer directly, without any conversion?

Regards,
-- Al

The planned release date for Windows 7 is October 22, 2009.

Many people are already using the preliminary "Release Candidate" version, and it has received overwhelmingly positive comments. Most notably, it runs well on computers that have less powerful hardware, while Vista requires high-powered hardware configurations to do its best.

The upgrade path from Vista to Windows 7 is somewhat confusing, and depends on which version of Vista you are upgrading from, and which version of W7 you are upgrading to. This article covers it pretty well. In particular, click to expand the second figure in the article. You'll see, for example, that upgrading from Vista Home Premium to W7 Home Premium can be done "in place" (keeping files, settings, and programs intact), while some other upgrade paths require a "custom install" which will require that you subsequently reinstall your programs, and restore data files from backups.

Regards,
-- Al

Arj & Cerrot -- Not sure if this is relevant, but I want to make you aware that firewire chips made by Via, which are widely used on many motherboards and cards that have firewire interfaces, have a long tradition of not working very well. TI (Texas Instruments) firewire chips are vastly preferable.

That is documented in many user posts you can find on the net, and I can tell you from personal experience that when doing digital video captures Via firewire chips drop frames at least every few minutes, while TI chips NEVER do, even in the same machine running the same programs. Although of course the data rates that involves are considerably higher than for audio.

You should be able to determine which chip you have by looking at the board or card, or possibly from the manufacturer's literature.

Hope that helps,
-- Al