"Scott" wrote in message
om
Hi,

I'm looking for a system that can sample 48 audio channels
simultaneously and ship the digital data over USB 2.0 / Firewire /
ethernet? to a PC. The data then is read in via a DirectShow source
filter, which I would be willing to write.

I've found the Edirol UA-1000 but an email from them stated I could
only chain 4 of them together.

I've found the Metric Halo Mobile IO DSP2882 and am waiting for word
if 6 of these can be used.

And on a related note, is there a two channel USB Audio device that
can sync up to an external clock?

You may want to investigate "Cobranet":

http://www.rane.com/pdf/cobrapps.pdf

http://www.qscaudio.com/products/network/rave/rave.htm

http://www.bss.co.uk/soundweb/produc...urBrochure.pdf

"Arny Krueger" wrote in message

"Scott" wrote in message
om
Hi,

I'm looking for a system that can sample 48 audio channels
simultaneously and ship the digital data over USB 2.0 / Firewire /
ethernet? to a PC. The data then is read in via a DirectShow source
filter, which I would be willing to write.

I've found the Edirol UA-1000 but an email from them stated I could
only chain 4 of them together.

I've found the Metric Halo Mobile IO DSP2882 and am waiting for word
if 6 of these can be used.

And on a related note, is there a two channel USB Audio device that
can sync up to an external clock?

You may want to investigate "Cobranet":

http://www.rane.com/pdf/cobrapps.pdf

http://www.qscaudio.com/products/network/rave/rave.htm


http://www.bss.co.uk/soundweb/produc...urBrochure.pdf

Whoops, not optimal for going to a PC. Was looking at the "over Ethernet"
part of the requirement.

(Scott) wrote in message . com...

I'm looking for a system that can sample 48 audio channels
simultaneously and ship the digital data over USB 2.0 / Firewire /
ethernet? to a PC.

I think you might be pushing the limit here, unless you're talking
about a low sample rate. I don't know how much faster than USB 1 these
newfangled interfaces are, but I'm not aware of anything that does
more than 8 channels in and out. I think you're barking up the wrong
tree here, and you should be looking for dedicated hardware.

And on a related note, is there a two channel USB Audio device that
can sync up to an external clock?

I think Metric Halo has a Firewire one. Is that close enough?
Understand that USB for audio applications may have progressed beyond
the "toy" category by now, but it's really for people who are afraid
to open up their computers and install real I/O hardware, or who need
portability. You have a pretty unusual application there, to record 48
channels of audio, and you shouldn't be trying to do it with hardware
that had different design goals in mind.

(Mike Rivers) wrote in
om:


I think you might be pushing the limit here, unless you're talking
about a low sample rate. I don't know how much faster than USB 1 these
newfangled interfaces are,

Theoretical maxima -

USB1 1.5Mbits/sec
USB1.1 12Mbits/sec
USB2.0 480Mbits/sec
F/wire 400Mbits/sec

A small improvement!

In article writes:

Theoretical maxima -

USB1 1.5Mbits/sec
USB1.1 12Mbits/sec
USB2.0 480Mbits/sec
F/wire 400Mbits/sec

Now if you can translate that into a practical number of audio
channels, we'll be getting somewhere. Any boob can look up the simple
specs. It takes an engineer to turn those into a practical product.




--
I'm really Mike Rivers - )

Mb/sec 16bit/44 24bit/44 16bit/48 24bit/48 16bit/96 24bit/96 24bit/192
USB 1.0 1500000 2.13068182 1.420455 1.953125 1.302083 0.976563
0.651042 0.325521
USB 1.1 12000000 17.0454545 11.36364 15.625 10.41667 7.8125 5.208333
2.604167
USB 2.0 480000000 681.818182 454.5455 625 416.6667 312.5 208.3333
104.1667
Firewire 400000000 568.181818 378.7879 520.8333 347.2222 260.4167
173.6111 86.80556
PCI 1056000000 1500 1000 1375 916.6667 687.5 458.3333 229.1667


(Assumes standard PCI interface of 32 bit, 33 MHz. Maximum theoretical
number of channels shown, not including any overhead or latency due to
transfers.)

"Mike Rivers" wrote in message
news:znr1062250799k@trad...

In article writes:

Theoretical maxima -

USB1 1.5Mbits/sec
USB1.1 12Mbits/sec
USB2.0 480Mbits/sec
F/wire 400Mbits/sec

Now if you can translate that into a practical number of audio
channels, we'll be getting somewhere. Any boob can look up the simple
specs. It takes an engineer to turn those into a practical product.




--
I'm really Mike Rivers - )

Yes, todays' physical links can move a whole lot of digital audio
channels.

I've looked at the Metric Halo devices - they looked very promising
but I was told by a rep that you could connect a maximum of 4 of them
together - I would need to connect 6 of them together for my
application.

I've done a preliminary look at the MOTU but I'm leary of custom
proprietary interfaces. Been there, done that, and just had to live
with too many wierd things and incompatabilities. Hence, I was trying
to go a route that used more "standard" interfaces (Firewire, USB2,
ethernet, etc) before trying out proprietary interfaces.

The Cobra Net and the Rane NM 84 looked good - I like the network
approach, but I don't see how multiple NM 84s can be synched to a
common clock source which in my app is critical.

I got excited about the Rave 161 but apparently there's no way to
snync multiple Rave 161's together so they sample at the same time....

I'll keep researching.....wonder if there's any data acquisition
devices that I could use...hmmmm....






Mike wrote in message ...
(Mike Rivers) wrote in
om:


I think you might be pushing the limit here, unless you're talking
about a low sample rate. I don't know how much faster than USB 1 these
newfangled interfaces are,

Theoretical maxima -

USB1 1.5Mbits/sec
USB1.1 12Mbits/sec
USB2.0 480Mbits/sec
F/wire 400Mbits/sec

A small improvement!

(Scott) wrote in message . com...
I've looked at the Metric Halo devices - they looked very promising
but I was told by a rep that you could connect a maximum of 4 of them

I wanted to correct the record - you can have six 2882's for 48
channels, but support for Windows is not available yet.....