I purchased the Musiland Monitor 01 US from a USA re-seller on Ebay for around $80 shipped. I have used the 01 US now for about a month and I thought that I would provide a brief review for those of you who are curious about a reasonable USB DAC that handles up to 24/192 audio.
The 01 US is a small portable DAC that is housed in an attractive curved gray metal enclosure with quality connectors. A single USB connector serves as the input while standard RCA analog phono jacks, a 1/8" stereo headphone mini-jack and an optical TOSLINK connector are the output options. The unit is powered by the PC via the USB connection.
The 01 US headphone output is controlled by your PC and player client (I am using Foobar 2000). The output has adequate power to drive my Beyer DT880s, although I prefer using the RCA high-level outputs to drive my various headphone amps. Most of my source library material consists of 44.1 FLAC files with some hi-res 24/96 and 24/192 FLAC files obtained from various HD music sites.
I have spent quite a bit of time listening with the DT880s and with my slightly modified JVC HA-RX700s (I tweak the high freq response of the RX7000s using Foobar's equalizer).
In short, this little gem delivers. With 44.1 FLAC files, the 01 US presents a huge soundstage with excellent depth. Imaging is rock-solid and individual instruments are nicely separated. Detail abounds and inner resolution is superb. But, it's the hi-res FLAC files that are the icing on the cake here - they sound wonderful with lovely, shimmering highs and deep, deep lows - analog sounding actually - definitely a step beyond my Esound and Harman Kardon CD players and perhaps even my Clearaudio Emotion turntable.
The Musiland driver client is not very sophisticated, however, and in fact is sort of the weak link in the package - the software has crashed several times. I would suggest keeping the SR Control setting on Auto in the Advance tab. I played with that setting and it ended-up causing the driver to get out of sync with different res files - the result was dropouts and it took me awhile to realize that I needed to re-boot the unit and the driver software. So, if you have a 01 US and the sound changes from perfect to well, not so perfect, re-boot the unit and the driver software (and possibly your client), before you start messing with anything else on your PC. Also, the driver (and accompanying documentation) is somewhat cryptic as the Chinese to English implementation is not exactly 100% intuitive.
Nothing's perfect in this world - the driver software is clearly a work in progress, but the Musiland 01 US is a compelling and amazing bargain for $80.