Pros: Format support, sound quality, amazing build quality
Cons: Front panel easily scratched, low output power
Excuse my English
First off the DAC is 24bit no matter if its on PC/Mac/Linux
it Decodes PCM 192K and DSD 2.8/5.6 MHz
Build quality: One of the best on the market. the casing of the unit is 3mm thick aluminum. Components on the circuit board are neatly laid out.
Sound Quality: I don't have high end headphones, but Low impedance phones really sounds good (<150 ohm). The sound is balanced.
Filters: Fast and Slow roll-off for PCM, Low and High cut for DSD. PCM roll offs are easier to notice for the bass, DSD cut off is just lowering the ampitude as some DSD are recorded over 0db
There are also other features:
Optical input and output, can be used as a converter. the output is always on.
RCA output, i also have powered speaker that I use with the HP-A4.
Specs from fostex jp website:
32 ohm load: 100mW
300 ohm load: 20mW
DAC chip: Taxas Instrument PCM1792A