USB to SPDIF converter, or that combined with good DAC

[anbello]

Although high-speed USB 2.0 nominally runs at a higher signaling rate (480 Mbit/s) than FireWire 400, typical USB PC-hosts rarely exceed sustained transfers of 280 Mbit/s, with 240 Mbit/s being more typical. ..." ... = bandwidth = 24 bit/96k, unidirectional only.

Maybe i don't understand which kind of calculus are you doing (i also have some problems with english) but 24*2*96000/1024=4500 near 4.5 Mbit/s for a stereo stream.

ciao
andrea

 

[FastEddy]

" ... Maybe i don't understand which kind of calculus are you doing ... "

The quote is from the Wikipedia entry, not my calculations. The suggestion that USB DACs may be able to perform above 24 bit / 96K is a commonly accepted upper limit from many of the DAC manufacturers. http://en.wikipedia.org/wiki/Firewire

Refer: http://www.m-audio.com/index.php?do=products.family&ID=USBinterfaces ... and ... http://www.m-audio.com/index.php?do=products.family&ID=FWinterfaces ...

Note that the FireWire DAC / ADC 's ["up to 24-bit/192kHz > high-definition digital audio"] often are capable of 6 or 8 channels of 24bit/96k or better for each channel, USB = not = limited to stereo @ 96k, 48k for dolby 5.x. ... Check out http://rolandus.com/edirol/ for a competitor = same, same [" UA-25EX is a portable-interface powerhouse with 24bit/96kHz resolution " ... " A 10x10 FireWire audio interface capable of 24-bit/96kHz at a full 10 channels in & out. "]

 

[anbello]

FastEddy,

If your quote are right (240 Mbit/s sustained transfers) you can stuff as much as 20 channel at 192KHz @ 32bit on USB 2.0.
Cmedia with his new chip compliant to "USB Audio Device Class Definition V2.0" declares "up to 192KHz/32bit" and "maximum 12 channels of output and input".

ciao
andrea

 

[FastEddy]

" ... you can stuff as much as 20 channel at 192KHz @ 32bit on USB 2.0. ..."

Not! ... show me a design that has done that and I'll kiss your a** ...

This kind of thing is not simple addition, multiplication or division ... everyone fails to account for such things as the "half duplex" operation, handshaking, top down topography, etc, etc, of USB.

 

[movvlab]

Hi,
Who used the IEEE 1394 to S/PDIF£¿

 

[FastEddy]

" ... Who used the IEEE 1394 to S/PDIF ? ... "

On the back of my cute little M-Audio FireWire Audiophile box (circa 2004) are all the inputs and outputs for: SP/DIF (co-axial) as well as MIDI I/O and a pair of 24bit/96k inouts (stereo) and two pair of 24bit/96k outputs (stereo x 2) plus the usual pair of 6-pin 1394a / FireWire 400 / iLink ports.

 

[spzzzzkt]

I use an echo audiofire2 which has spdif i/o on a breakout cable. One pair each of balanced 1/4" ins and outs.

It would seem that now Apple has ditched FW400 from all their new laptops that the future for FW audio interfaces isn't looking quite as bright....

 

[Kane Williams]

Well I think that we will start seeing many new devices based on the USB 2 audio specification.

I'd love to buy the JAVS DAC-1 Overture but can't afford it at the mo, so I may go for the UHF-1. Both devices use USB 2 with no special drivers and apparently offer low jitter clocks etc.

 

[movvlab]

the 1394 to SPDIF converter Should be a more high-quality audio output.But to see the product or very little, In particular, DIY kit

 

[movvlab]

Hi,FastEddy
You should be in the sound card application, there are some professional sound card interface is 1394, such as the RME FF1394.but,There are rare DIY kit.

 

[FastEddy]

" ... I use an echo audiofire2 which has spdif i/o on a breakout cable. One pair each of balanced 1/4" ins and outs. ..."

I prefer the AudioFire4, but there is no technical differences between the two except the number of I/O balanced analog ports = both use the same chips, drivers, etc.

" ... It would seem that now Apple has ditched FW400 from all their new laptops that the future for FW audio interfaces isn't looking quite as bright ..."

Mmmmmm ... and I suppose this is because few laptop owners lug their recording studios, quality stereos and video equipment around with them. You might also notice that no WinPC laptops have FW400 / FW800 interfaces either, except as slot supported options. (Same, same on laptops with SCSI, Fiber Channel and the rest.) The real reason that all new laptops do not have a plethora of fancy ports = battery lifespan. Any port that has off board power is highly regulated by laptop circuitry to become anemic as batteries draw down. Hooking an external bus powered hard drive to a new laptop with a half charged battery? = Not!

Of interest = these all have FW400 and/or FW800 ports:
http://www.apple.com/imac/specs/ (I have one = love it) ... http://www.apple.com/macmini/specs.html (I have three = love 'em) ... http://www.apple.com/macpro/specs.html (I gave mine to my nephew = he loves it) ... http://www.apple.com/xserve/specs.html ... http://images.apple.com/macpro/images/specs_ports20080108.jpg ...Apple blade servers have FW800 ports 'cause that's the fastest way to do co-processing. I also have a two year old iBook, but I burned the FW400 port on it playing around with a volt meter
Desktop type HP, Dell, etc. ... offer FW400 & FW800 ports as options, but you have to have DIY yearnings to add these. The better FW port cards are less than US$30 (avoid VIA chip sets).