If you’ve attended either of our recent Tips 'n Techniques seminars, you’d have heard our Director of Performance Systems, Craig Finer, speak on digital audio and it’s various delivery methods, especially pertaining to Hard-drive based storage and the associated equipment used to retrieve those 1’s and 0’s and turn them into “squiggly waveforms”, or an analog music signal. I’m going to briefly touch on the categories we’ve covered and mention a few of our favorite examples in each category, as well as sum up some of the basic file formats and which ones we recommend using.
Music ServersA dedicated music server is something that we would categorize as having it’s own method of storing information, with it’s own interface software and GUI (Graphical User Interface). Often the storage is internal, as in the instance of a PC/Mac or Apple iPod, which you can purchase with either a HDD (Hard Disk Drive) or SSD (Solid-State Drive). Sometimes, as in the case of our
Sooloos and
Kaleidescape products, the storage is externally located but in a proprietary fashion using a custom file system native to the particular product. The Sooloos in particular, we feel, is our best example of a Music Server since it comes with it’s own display, storage, and also offers great sound quality (courtesy of the parent company, Meridian) to boot. Most of the time, these products are the easiest to use and set up, and often don’t require much expertise in terms of computer know-how. The downside in the case of the PC/Mac or iPod type solutions is that you’re leaving the digital-to-analog conversion up to either inexpensive or simply poorly implemented DAC circuits that are more susceptible to issues like noise, interference, etc. since they are in a computer environment, which is not an environment which seeks to delicately nurture the analog music waveform.
USB DAC’sA USB DAC takes the music off a PC or Mac through the USB output to turn it to analog. The theoretical advantage is that the USB interface is less prone to “jitter” or word clock timing errors than the typical SP/DIF Digital Coax or Toslink Optical connections on a computer sound card, thus able to retain the digital bitstream much more accurately before reaching the DAC. Another inherent advantage is that you will be able to use the interface you prefer (iTunes, Windows Media Player, WinAmp, JRiver, etc.) to manage your music library. A few examples of USB DAC’s would be our
Audio Research DAC7,
Ayre QB-9, and
PS Audio Digital Link III. The Ayre QB-9 is unique since it is one of only a few USB DAC’s that uses a technology called asynchronus USB, which essentially uses a buffer to store the digital information before it gets sent to a fixed-frequency master clock, thereby virtually eliminating jitter. This is a bit different from the variable-frequency clocks that are found in the adaptive USB DAC circuits commonly in use. Many of the DAC’s on the market also offer multiple inputs so that you can hook up Cable or Satellite boxes, DVD players, Blu-ray players, or an older CD transport. Make sure if you are using a USB connection to ask us to demonstrate a
Transparent Performance USB cable, you’ll be surprised!
Network Music PlayersA Network Music Player retrieves the digital music information over your home network. Most Network Music Players will have their own interface and controller, such as a
Sonos or
Logitech Squeezebox. They typically utilize a protocol dubbed UPnP, or Universal Plug and Play, to communicate with software that scans your music library and serves it to the player over the network. The most common way to store music using a Network Music Player would be to use a NAS (Network Attached Storage) device. The
Linn DS is our best performing example of a Network Music Player, though it does not come with any way to remotely navigate your music library. The digital music information is streamed over the network to an internal buffer (similar to the Ayre QB-9) in the DS, which then sends the info to an extremely low-jitter word clock to be sent to the DAC circuit, which is designed by Linn’s team of engineers experienced in the art of designing world-renowned source equipment.
File FormatsThere are many different ways to convert the information on your 5.25” CD’s to digital files on a computer. The most popular way to store music on your computer hard drive is the MP3 format, which is also probably the worst way to do so, since it is typically an extremely “lossy” form of compression. Similar compression schemes are WMA and AAC, as well as other various formats. We strongly recommend avoiding these “lossy” compression algorithms since they throw away much of the original information on the disc. The alternatives are to use no compression, or “lossless” compression. WAV and AIFF files are the exact data from the disc with no compression, but do not have very good “tagging”, which gives you artist, track, title, album art, etc., and also take up more space on your storage drive. A “lossless” compression, such as
FLAC (Free Lossless Audio Codec) or
ALAC (Apple Lossless) take up about 40-50% less space on average than a typical uncompressed WAV file, have great tagging capabilities, and are virtually indistinguishable from the original file since they use complex coding schemes to retain all of the original data. We typically recommend using a lossless compression since it’s all of the original data with the convenience of less space and great tagging. If you’re a PC user, FLAC is the best way to go and has the most flexibility. If you are an iTunes or Mac user, ALAC is the alternative since FLAC is currently not supported by iTunes.
I will be covering some of the products mentioned in further detail in the future. Hopefully this serves to help guide you as to what type of product may be suitable for your application, but in the meantime, if you have questions, stop by a showroom and we’ll be happy to help find the right solution for you!