Converter is a Sonic Studio model 302 (relabeled Metric Halo ULN-2)
I could run audio straight to and from this box through firewire, but that would limit flexible patching of other digital outboard gear. Now i can route anything before DAC and after ADC using a digital patch matrix.
Playback DAW #1 has an old Lynx One PCI card sending via AES i/o to a Z-Sys digital patchbay which mults the signal to two sets of Lavry Blue DAC's - one which feeds the monitor controller for direct monitoring of the source files, and the other which feeds the analog process chain.
Capture DAW #2 has a Sydec/SSL Mixtreme192 PCI card attached via TDIF to a Soundscape/Apogee 896i/o interface which has 8 channels ADC/DAC, and 8 channels AES i/o - which feed from/to a Mytek Stereo96 ADC and Lucid DA9624 DAC via Z-Sys digital patch bay. I'm planning an upgade of these last two pieces this year - likely to a Lynx Hilo.
I should note that both of these PCI cards I use are discontinued now - but since they provide all needed i/o and can plug into any converter upgrade desired via AES - since they still function perfectly for my needs, rather than putting studio budget funds into unnecessarily updating them I put them into gaining additional capabilities for the studio instead.