USB 2.0?

[canhoto]

Hello.

If I have a compute with USB 2.0 ports and a USB 2.0 audio card, like, for instance:

- Focusrite Scarlett 2i2
- Alesis io2 Express or io4
- M-Audio Fast Tack Pro or Fast Track Ultra

Will it work at 2.0 speeds? Because I'm hesitating between a firewire card (like the Edirol FA-66 or the Presonus Firestudio Mobile) and one of those USB's.

Thanks

[j_e_f_f_g]

Will it work at 2.0 speeds?

Yes.

a firewire card

Don't get firewire. It's effectively a dead technology today. Support can only get worse now.

[autostatic]

+1. I just bought a new notebook and it has nothing, no FireWire and even no PCI Express. USB2 and USB3 seem to be the future.

[Shadow_7]

The usb 2.0 audio standard was a bit slow to get adopted. And firewire was a player in that condition. But it's hard to find a firewire capable machine off the shelf these days. So USB 2x or 3x would be the safer bet imo. I don't think we'll see much in terms of USB 3x devices for audio anytime soon, but usb 2x devices do exist now.

When I was shopping for a camcorder, firewire was a factor. The one I wanted at the time was firewire based. But none of my current machines had it, so I had to factor in getting firewire into the costs of that device. Which basically ruled it out since a comparable device in USB came around before I had the funds to buy it. If you don't plan on doing a lot of mixing and post production, most usb 1x devices are sufficient in my opinion. More so if you have a good recording space and good off device preamps.

[eikakot]

are alesis products USB class 2 or class 1 compliant?

[canhoto]

are alesis products USB class 2 or class 1 compliant?

Class 2.

[infolix76]

I own an Alesis IO2 express and it works fine

[falken]

Are you sure, that USB 2.0 noted above are also HIGH-speed devices?? I am almost sure they aren't as according to io2 Express manual, USB 1.1+ cables are required, which implies max FULL speed. Also if true HIGH-speed chipsed certified is used, its also almost sure that company will place cerified logo on the box and HS recommends to use better cables

It really doesnt matter as far as you know about Multi-TT hubs and full/high speeds injection and its OK that such adapters are fast enough to transfer required streams of full-duplex AUDIO at given max specs. Internally its not full duplex though, nor with USB2.0 HS. Only USB3.0 uses true full duplex signaling but this spec also does till now nothing in common and useful with audio, as application layer protocols (usb-audio class 1.0 used probably, there is still few class 2.0 chipsets) are the same as for USB2.0 - it seems 3.0 fixes and endances/optimizes some bus behavior though, even for backward compatible devices, may be also usb-audio, but in this case, such card is still only FULL-speed over the blue 3.0 too.

Cheers,
Petr

PS: usb-audio class 2.0 over HIGH-speed USB2.0 bus chipsets I only know till now, are:
http://www.xmos.com/products/reference- ... /usb-audio
http://www.cmedia.com.tw/ProductsDetail ... no-43.html

[lazyklimm]

+1. I just bought a new notebook and it has nothing, no FireWire and even no PCI Express. USB2 and USB3 seem to be the future.

Not the best future possible :/

[Thad E Ginathom]

One of the great USB audio confusions --- at least for me.

There is USB1.0 ans USB2.0 (and now USB3.0). USB1.0 (which never found favour for audio of any kind) must be fully obsolete by now and only found on ancient machines.

Then, as a subset of USB standards, there is USB Audio Class 1 (with limited sample rate) and Class 2.

Errr... right?

[falken]

Then, as a subset of USB standards, there is USB Audio Class 1 (with limited sample rate) and Class 2.

Errr... right?

ya, USBx.0 is in fact physical layer and signaling specification, having 1.1 as bugfix to 1.0 in fact, there was some early consumer skypephones 1.1 chips but for even better behavior on the bus, they was updated to 2.0 spec (both allows 1Mb/s=LOW and 12Mb/s=FULL speeds though). USB2.0 adds also 480Mb/s HI-SPEED as NOT MANDATORY, often you can see specific Hi-Speed LOGO on the device or its box at least. I dont know if there are some Hi-Speed devices which arent "certified" so cant use such logo... really dont know...

The usb-audio CLASSes are the protocols used over physical link, theoretically doesnt matter which one (but higher specs learned from quirks, particulary in highly stressed isochronous transfers priorities, the hubs behavior, simply , there are "bugfixes" and may be new bugs too).
They are described here: http://www.usb.org/developers/devclass_docs (and it isnt too difficult to scan through them - in fact Class 1.0 still allows many channels and high resolutions/rates, at least I cant see limits in PDFs - truth is, that regular drivers expects only hardware to some near future - class 2.0 is far more complex as a result of standardization between current market state of "custom" pro-audio solutions)