I like to record my sounds of my amp (VOX VT40+) using a microphone (e.g. the Shure SM57-LCE) and an audio interface (e.g. Focusrite Scarlett 2i4), but I did not buy one of these, yet. I was wondering why all the audio interfaces I've researched do not support USB 3.0. Any idea why? Somebody told me, the advantage of using a Firewire interface is that it does not need to compress the sound, right? Would USB 3.0 fix that issue?
Best regards, Michael
I don't know where you read about USB interfaces needing to "compress the sound", but it's nonsense. For your application two channels will do; at 96 kHz and 24 Bit that's less than 5 MBit/s: even USB-1.0 can handle that without compression. and USB-2.0 is already more than ten times faster, so even in multichannel applications it's often plenty good enough.
What's taken as crucial for the performance of an audio interface is not so much bandwidth as latency, in particular when you're dealing with virtual instruments. FireWire has a design advantage here, not because of its higher data rate but because its topology allows devices to interact directly, and it can pretty much completely be implemented in hardware, with very reliable DMA performance. Whereas in USB there's a single root hub that needs to do some nontrivial packet management – not an issue for total bandwidth (just use big enough packages!), but it prevents reliable fast direct-memory access.
And this hasn't really changed with USB-3.0: it offers much better bandwidth than 2.0 (which however, as I said, is relevant only if you need a great lot of tracks) but is still worse than the old FireWire in terms of low-latency reliability, and much worse than Thunderbolt.
Again for your application, when you're recording from the amp with a microphone you don't need monitoring through software anyway, so latency doesn't matter either. So there's really no reason why you shouldn't be fine with just a USB-2.0 interface.
Focusrite Scarlett and an SM57 should be just fine. Combine it with a DAW like Ableton, Pro Tools, Cubase, Reason, Logic, etc, and you'll have a good setup.
leftaroundabout mentioned many of the main reasons so I won't repeat them all, but the main reason is that USB2 is often not the bottleneck for recording applications unless you're doing extremely large scale recordings. As well, USB2 is forward-compatible (in theory) with USB3, so there's very little reason to change what is working so far.
Also to consider is that Thunderbolt is now starting to gain traction, which has a higher bandwidth and some other conveniences that USB3 doesn't have, and is more or less an outboard PCI slot, so I think many companies will lean towards this and hold off on USB3 (like the UAD Apollo).
RME have released this USB3 interface, but you can see it's mainly because of the MADI interface.
There are some but I believe the main reason as to why there aren't more is that:
If as an example I were to purchase a USB 3.0 compatible interface like RME's MADIface XT or a Firewire 400/800 interface and use a converter to USB 2.0 to connect to the existing USB ports in my laptop, Would the converter automatically lower the speed and clarity rendering it pointless to pay extra for a faster interface?
https://stackoverflow.com/questions/13831008/what-is-the-minimum-latency-of-usb-3-0
Looks like USB 3.0 has a much lower latency than USB 2.0 and it would allow for things like playthrough recording. I'm guessing that the only thing holding things back is the money required to hire engineers to design equipment. ie. it probably costs less to hire engineers to copy someone else's design than to be earlier on the market, hence the high cost of the first usb 3.0 device.
There will probably be a USB 3.0 device under $500 within a year or two now that almost all new laptops come with usb 3.0.
