Yeah, the 48kHz is a deal breaker for me as well. It was something that I was pretty adamant about having, but after seeing it in practice the analog outputs are far better.
And SPDIF is a consumer format and it really does show. I used a different audio interface prior with SPDIF from the AxeFX and it wasn't usable. Monitoring was a real pain, but I got jitter (not just perceived, it was audible and almost sounded like a weird form or aliasing). Basically the issue comes from taking two devices with independent clocks driving them; they can both be set at 48kHz, but they aren't synchronized and in reality they are going to be more along the lines of 48004Hz and 47993Hz...not a good idea.
These are two questions I still have:
1) I'm monitoring a digital input into my Fireface 400, but I have not switched the input to DIGITAL ONLY. I had thought from reading someone's post that that was impossible, so what am I hearing in the fireface on the SPDIF channel then, if not the Axe FX digital output? Also, my Fireface clocks to it, because it shows up in the Fireface control panel that the sound card is receiving sync from the Axe FX.
This next question assumes I am actually monitoring and recording digital signal on the SPDIF in my Fireface (a logical conclusion - maybe).
2) Is the fact that I'm running an RME Fireface off the Axe's 48k clock (and the fireface theoretically has some technique for correcting aliasing on-the-fly) allowing the SPDIF, be it consumer-aimed crap, to do better than what was intended, giving me a signal that is fairly jitterless?
Because 2 weeks ago I got SPDIF cables, and ran them between the Axe and the SPDIFs on my Fireface400.
And believe it or not I actually like having the SPDIF,.
I can't prove the difference, and I wouldn't put my life on it, but it FEELS at times like a tiny bit cleaner/brighter recording, when played back, in some cases, like if I'm doing something that has a lot of stereo imagining and higher frequency reverbs, the presence clarity seems EXACTLY like what I hear, whereas if I've recorded from the analog IN's in the Fireface the signal may be more like ALMOST exactly what I hear. Of course, I have both plugged in, and both signals show up in the Fireface mixer. And I can't detect the difference really when monitoring directly, but only when playing back the recording.
Well, mainly I like the fact that it sounds different, which means its not a complete waste to have gone out and purchased the SPDIF cables. At least there appears to be a difference - that I think I can detect. (hear the difference it helps that the guitar strings are very spanking new (less than 6-8 hours of play is best - but I've tried putting white mineral oil on the strings and this seems to make them last longer). The other part of this is that I'm usually running a few chunky vst synths during recording, so maybe doing analog recordings was just requiring still one more layer of processing, whereas directing copying the (possibly corrected un-ailiased) digital data from the Fireface 400 is less in terms of overhead. This is SUPER specialized-technical stuff, so I would like some guru who knows the Fireface to give feedback on if this is possible, and if there is a difference in the recordings of analog versus digital.
BTW I am a vinyl junkie, so its totally ironic that I would like something better about digital outputs, and here I am now using a digital emulator of tube amps. But still, avoiding adding yet another level of Analog-To-Digital DOES make sense to me, since I suppose there is more of the carving off of natural, organic sounding data that the digital world of the Axe FX uses that 600+ Megahertz processor in the AXE FX to busily re-invent.
Ah well, there's a chance life is one big mystery, even when they smile, tell you to go by the numbers and not worry about the "harmless digital truncation".
