Support of audio interfaces under Linux
Posted: Sun Sep 30, 2012 7:09 pm
Be careful in any assumptions you make in regards to Linux audio support because frankly, most Linux audio support is done by unpaid volunteers, and as such they typically do "just enough" support to get basic functionality, but not much more. For example, just because an audio interface supports 24-bit resolution (under windows or MacOS) doesn't mean that Linux supports that. Some features are selected/controlled/implemented in the Windows/MacOs software drivers themselves. The ALSA driver must go beyond class compliance, and instead support the interface's proprietary protocols. The ALSA driver may not do that.
And just because an ALSA or FFADO web page lists a certain device is "supported", take that with a very big grain of salt. For example, before I bought a MOTU Ultralite interface, I checked that the FFADO page said it was "supported". What I later discovered is that only the first version, not the later two versions, is supported. Typical of linux's lack of uptodate, accurate info, the web page didn't document that. So I did some more research and discovered from the ALSA support page that the EMU 1616M is "fully supported". And sure enough, after I bought one and tried it with linux, I discovered that ALSA "fully supported" it only at 16-bit, not its 24-bit operation. Another example of linux audio's "quasi-support" is that the Focusrite Saffire 24 DSP "works"... except for none of its DSP effects.
I can't directly answer your question about those 3 devices you're considering, as I've not tried them myself. But I can tell you that, unless someone has one of those devices, and tests that the features you want actually work under linux, then the safest tact (and unfortunately most probable outcome) is to assume that the features are not supported. If someone simply says he "thinks" that the support "should work", take that as "it probably doesn't since no one can definitively confirm it". And if the "confirmation" is to cite any info on an ALSA or FFADO "support page" then take that as questionable verification since the docs for those projects are deceptively misleading at best. "Support" means something entirely different to an ALSA/FFADO developer than it does to someone who intends to actually use a device's features.
I went back to using Windows for music. I can deal with limited functionality if I'm made aware of it beforehand. But given the outdated, inaccurate, and inadequate documentation regarding the state of linux audio, using linux for music making goes beyond dealing with limited functionality, and becomes a frustrating experience of unpleasant surprises and a relentless parade of problems at every step.
Take the plunge only if someone has already done exactly what you want to do, with the exact same setup, so that you can be sure what issues you'll face, and whether it will even work.
And just because an ALSA or FFADO web page lists a certain device is "supported", take that with a very big grain of salt. For example, before I bought a MOTU Ultralite interface, I checked that the FFADO page said it was "supported". What I later discovered is that only the first version, not the later two versions, is supported. Typical of linux's lack of uptodate, accurate info, the web page didn't document that. So I did some more research and discovered from the ALSA support page that the EMU 1616M is "fully supported". And sure enough, after I bought one and tried it with linux, I discovered that ALSA "fully supported" it only at 16-bit, not its 24-bit operation. Another example of linux audio's "quasi-support" is that the Focusrite Saffire 24 DSP "works"... except for none of its DSP effects.
I can't directly answer your question about those 3 devices you're considering, as I've not tried them myself. But I can tell you that, unless someone has one of those devices, and tests that the features you want actually work under linux, then the safest tact (and unfortunately most probable outcome) is to assume that the features are not supported. If someone simply says he "thinks" that the support "should work", take that as "it probably doesn't since no one can definitively confirm it". And if the "confirmation" is to cite any info on an ALSA or FFADO "support page" then take that as questionable verification since the docs for those projects are deceptively misleading at best. "Support" means something entirely different to an ALSA/FFADO developer than it does to someone who intends to actually use a device's features.
I went back to using Windows for music. I can deal with limited functionality if I'm made aware of it beforehand. But given the outdated, inaccurate, and inadequate documentation regarding the state of linux audio, using linux for music making goes beyond dealing with limited functionality, and becomes a frustrating experience of unpleasant surprises and a relentless parade of problems at every step.
Take the plunge only if someone has already done exactly what you want to do, with the exact same setup, so that you can be sure what issues you'll face, and whether it will even work.