Hi there
I thought I'd add my own take. I've spent several months looking around at getting a decent audio interface, seeing whats available and how to go about picking the right one for myself. I have no personal experience, everything I've learnt so far has come from reading and discussion.
I'll use it for recording, re-amping and using a DAW for: Mobius looper; VST effects in the Axe's FX loop; MIDI synched sequenced backing; and sometimes to play live VSTi synth routing it through the Axe effects.
This means round trip latency is a big consideration. I'd like it rack mounted. Firewire. Minimum of 8 in 8 out analog, at least one of which is instrument input (preferably more), at least 2 mic pres ins, all balanced outs. ASIO compliant (ruling out Lexicon). SPDIF (not ART, Mackie Onyx nor MoTU 8Pre) and at least one MIDI 1x1 would be preferable. As would ADAT and Word Clock. Plus the ablity to work stand-alone, (which rules out Focusrite).
Apparently all USB audio interfaces use double buffering, with only a few (USB AIs) managing a reasonable level from RME and M-Audio only. Many Firewire AIs appear to have lower latency, so I'll stick with that and use a dedicated TI chipset port.
Turns out this is a tall order for someone on a budget. I started with a list of most of the products of reputable brands that fit most of my requirements. Then went looking around the net to find out as much as I could, reviews, manuals, forums, etc. The more I learn about audio latency, audio sync, round trip latency, along with many issues so many products out there have, the list has become very short.
Just before I read this thread, I was seriously considering the M-Audio Profire 2626. Thank you so much for pointing to that thread, yet another bullet I've dodged! It's something I've been experiencing quite a bit.
A recent example is the Echo Audiofire Pre8 which looked so good, in theory. The reviews were great, great sound quality for a reasonable price. It has most of the features I want. But sadly I discovered its round trip latency is not good at all as it uses a lot of buffering which doesn't stack up well against other products. I think if someone as only going to use the Audio Interface for recording, possibly using latency compensated backing for takes, it'd be really good. Also if you're going to use your computer all the time with the audio interface, the Focusrite Pro series seem good too. Sound on Sound have reviews on both. I have no experience, I'm just voicing what I've read and collated. Other brands that had products that fit my requirements I've looked into are: Alesis, Apogee, Art, Cakewalk, Mackie, MoTU, Lexicon, Presonus, Steinberg, TC Electronic.
With M-Audio Profire off the list, right now RME Fireface 800 is the last remaining contender on my list. I never considered spending that much money on an AI but now I can understand why its worth it. The Axe FX is a great sounding machine and I want to make the most of it. But if I'm going to sink that sort of money, I want to make sure it'll deliver and keep delivering for years to come.... like the Axe.
Firewire AI's on the whole have less latency than USB AIs, but you can't beat a decent sound card that slots into the machine. Because of this I'm now re-considering a rack PC with good audio PCI or PCIe audio card. However rack mounted PCs bring a whole bunch of other costs and headaches I'm learning about and want to sort out before I even consider which audio card.
I've learnt quite a bit from Vin/TAF KAT's posts recently. He resides on a few forums and appears to be heading a project to set a standard bench mark for on DAW/audio interface audio latency and get as much information as possible. Here's a recent thread with what he's measured to date:
Audio Interface - Low Latency Performance Data Base : - Gearslutz.com
I've found many DAW and audio related Forums are a great resources, but it's been very time consuming filtering through the vast amount of material.
Also solid MIDI sync is a high priority to me too; I use a Gordius midi controller as master midi clock. I'm also on the hunt for a decent Firewire multi-port MIDI interface. A good solid reliable one. I've only found USB MIDI adapters or 1x1 MIDI on an audio interface. There are many issues with MIDI jitter and latency which I want to mitigate as much as possible.
Finally I've found this site informative on the topic of synchronising MIDI hardware
Innerclock Systems - Precision Midi Clock Din Sync and Tempo Synchronisation Solutions
Some really interesting content.
I'm relying only on what I've read and discussions I've had, so I'm keen to hear from others who have experience. I just want to do my homework first and get it right first time around, I'm trying to avoid learning the hard way.
Cheers,
G.