This is a good review - although he does seem a little hung up on price, with Mirus not being quite the best he's heard because it's not the most expensive. But generally I agree with most of what he says. He references a (more expensive) tube DAC as being slightly more weighty, and if you read his review of that same DAC he called it warm and "tube-ish", so it makes sense.
A lot of DACs these days use an FPGA.
What they use it for can vary though, as can the make and model of FGPA being used. Since an FPGA is really a sort of "customizable semiconductor" it can have a wide variety of uses depending on the needs of each particular design.
Xilinx and Altera are the Big Two of the FPGA world, holding something like 90 percent of the market share. Xilinx seems to be used in more audiophile applications, but I've seen Altera used as well. These are major, multi-billion dollar companies, who are locked in a sort of Intel-AMD rivalry (but a more evenly matched version where neither side has a consistent advantage) - a rivalry which transcends any particular application such as audio design. The chips will keep evolving, no question, and it's up to the DAC designers to decide if they can use the extra horsepower or not
PS Audio claims to do all D/A conversion within the FPGA. Hugo does a ton of things inside the FPGA but the D/A conversion itself is done by their discrete "Pulse Array" DAC (it's a common misconception that the FPGA does the actual conversion). In this way, Invicta is closer to Chord than PS Audio. Their FPGA handles many things via custom programming. Resonessence even made their own video driver through the FPGA, to power the HDMI output - which I think is pretty clever.
Lots of other brands use FPGA as well, though in more simplistic ways. The NuForce DAC100 has a Xilinx (older Spartan version) and I suspect it is for jitter reduction, which is a pretty common function:
The Firestone Tobby uses one (also an older Xilinx) tied in with their digital clock generator, which is a novel use as far as I know:
Oppo uses an Altera Cyclone in their BDP-105. It sits next to the Mediatek and Silicon Image chips that handle video stuff, so it's probably not audio related (sorry it is covered by the heatsink):
So it really comes down to the designer and their ability to use the FPGA. Sure, the latest model (Spartan 6 is
not the newest or most high-end chip in the Xilinx stable) might sound good on paper, but it's just a tool that doesn't accomplish anything on its own. It might help to think of it as a coding language more than anything else. It's hard for us amateurs to judge directly because we can't look at the code and see the elegance or clumsiness it may contain. That's why we have to judge by listening (or marketing claims if that's what gets you excited).
Thankfully, so far it seems the DACs using heavy FPGA functionality all sound good or great. The time may come when that is no longer true, as FPGA use becomes more common.
Not a stupid question at all! I love both devices and use both quite often.
Personally, I think my Mirus is a step ahead of the Hugo in almost every way. It's got the same extreme resolution and purity of tone but with more tonal density, making for a more convincing sense of body yet not going too far into overly warm NOS/tube DAC territory. It also seems more well controlled in the upper mids, where Hugo can be a little bright once in a while. Plus there's the design in general - proper sets of inputs and outputs, no crowding, WAY better user experience, etc. Is it worth upgrading? Depends. How much does Hugo frustrate you in terms of controls or limitations? The SQ improvement may or may not be worth it depending on your system, but the usability improvement is clear for anyone to experience.
