I thought I would take the time to report on my recent experience with The HAL MS-2 PC Music Server. To begin I really appreciated the MS-2's design, it's 8"x8"x2.25" size allowed me to put it right on the same shelf with my USB DAC. All I had to to do was connect my USB external HDD, wireless mouse/keyboard dongle and HDMI cable for display and I was good to go.
I approached this demo as somewhat of a scientific experiment. Both my computer, a Toshiba Satellite 875 laptop and the HAL MS-2, run Windows 8 and have 8G of RAM. They are also running the latest version of Foobar with all configuration settings duplicated on both machines. The single variable between the two systems is the amount of noise the Toshiba laptop injects into the USB connection between the DAC and the computer.
The differences between the two computers playing back the same music file were quite substantial and entirely on the side of HAL MS-2 PC Music Server. Playback of files from the MS-2 resulted in better resolution across the entire frequency spectrum. The highs had better extension and detail,the mid-range had a more complete sense of harmonic density. The images in the sound stage had greater solidity and 3 dimensionality. The bass was deeper, better defined and showed more texture with a broader tonal palate.
The Toshiba laptop's increased levels of noise resulted in masking of low level detail, a decrease in the size of the reproduced acoustical space contained in the the recording as well a loss of dynamic contrast that the recording could exhibit. In addition the to the aforementioned loss of information contained in the recording, the increased noise also had the effect adding an excess of upper mid-range energy which substantially increased the listening fatigue I experienced when listening to the laptop feeding the USB SABRE DAC.
The greater the resolution the DAC has, the more obvious the differences are. I used a Cambridge 740C via its SPDIF coaxial input fed from a TENOR 7022 chip's SPDIF output. Even though the Cambridge 740C has a substantially modified analogue output stage, this player almost qualifies as a vintage piece in the ever evolving world of replay via computer based files. I started playback from computer with the DAC section of the 740C almost 5years ago and this piece is now functionally obsolete. All serious evaluation was done with an EES Tech based USB DAC. The SABRE DAC sports an 225watt external power supply and is not powered by the USB buss. Even though it is not dependent on USB power apparently the noisy laptop environment also impacts the data lines as well as the power buss. The DAC's independence from the USB buss does not solve the problems that the laptop brings to the table.
A conventional multitasking computer used for everyday applications sets a hard upper limit on the performance one can expect from computer based music playback. A "better" DAC and a more expensive USB cable will not significantly improve your performance until you deal with problems stemming from the computer itself. In my opinion the HAL MS-2 is a spectacularly effective solution to the limitations on system performance that are imposed by a regular computer.
I purposely saved the best for last. When high resolution files are played back via the MS-2, the differences between CD resolution 16/44.1 files and 24/96, 24/192 and DSD via the DSDIFF decoder in Foobar are striking. There will no-longer be any questions regarding the sonic superiority of the Hi-Rez formats when they are compared to CD resolution 16/44.1 files. When the masking and information loss is dramatically reduced by using the MS-2, the concept of building a library of Hi-Rez recordings starts to make sense.
I would highly recommend the addition of the HAL MS-2 to anyone who seriously wishes to improve their system's reproduction of music from computer file based formats.
Needless to say a MS-2 is at the top of my short list for acquisition next year. Until then I am going to have to suffer with replay from my laptop.
A big thank-you to Rich for the demo and the ease of setup of the MS-2!