Lansonic DAS-750 Digital Audio Server 
Home Theater Media Servers Music Servers
Written by Kim Wilson   
Friday, 01 December 2000

Lansonic™, a division of Digital Voice Systems, Inc. (DVSI), a leader in the field of voice compression, has introduced the first unit in what may be a brand-new product category. The DAS-750 Digital Audio Server is a high-performance audio product that stores and plays music files, decoding all the standard MP1/MP2/MP3 compression rates, ranging from 32 kbps to 448 kbps (kilo bits per second), as well as uncompressed WAV files. Depending on the configuration, the unit ranges in price from $695 to $ 2,595.

Unlike a PC that emits high levels of hum, noise and heat, the DAS-750 is far better suited for storing and playing a wide range of music files, since it employs 20-bit crystal A-to-D and D-to-A converters. Analog output is measured at 96 dB SNR from 0-22 kHz, which is considerably better than the typical computer soundcard. The DAS unit also contains a programmable 40-bit Digital Signal Processor to perform all the audio processing functions and a built-in spectral equalizer that makes fine adjustments to the frequency response.

Designed to fit into a home audio system, the DAS-750 includes an extensive array of standard analog and digital audio inputs and outputs, such as three stereo analog (RCA) and four digital (two optical and two coax) connections. The analog (one stereo pair) and digital (one optical and one coax) outputs are used for hooking up a variety of recording devices like portable MP3 players, CD-RW and MD recorders.

Another reason to integrate the DAS-750 into a home audio system, rather than a PC, is that the DAS does not require a fan. The patent pending SuperQuiet™ drive technology used on all DAS internal drives results in the reduction of noise commonly generated by hard drives. The DAS-750 was as quiet and unobtrusive as any other audio component in my system.

The DAS can be purchased with a variety of storage options, with the basic configuration containing a 20 GB hard disk ($995) that can store about 350 hours of music at 128 kbps. There are two drive bays that can be outfitted with 20, 60 or 120GB drives. When two 60GB drives are installed, the DAS is capable of delivering 2000 hours of music ($1,995 for this configuration). Hard drive upgrades require returning the unit to the factory.

A diskless version (for $695) can be used for additional terminals on the network. When one of these diskless terminals is placed in a different room, it can call up playlists from the server. Playlists can be created on the terminals, using files from the main server. Even with the addition of terminals in other rooms, only one server is required for a whole-house audio system.

For the ultimate setup, there is the DAS-750 Pro, which includes an RS-232 port for integration with automated systems such as Phast and Crestron. It retails for approximately $500 more at all configurations.

Currently, the DAS is limited to stereo output, either analog or digital. The manufacturers are considering new-generation models with multi-channel capability, in the event that multi-channel music becomes a mainstream reality.

For integration with a PC through a wired or wireless LAN (local area network), the DAS includes a built in 10-Base-T (i.e. 10 Mbps) Ethernet connection. It can also be linked directly to a PC with a crossover cable. It is advisable to use the higher bit rate network, but when that is just not possible, a dual-rate hub must be used so that the DAS unit will interconnect with a 100-Base-T (i.e.100 Mbps) network. Once configured on the network, the DAS hard drive will store any kind of file, including text and/or images. Therefore, besides being a digital audio server, the DAS can be a backup hard drive to your main workstation.

The DAS communicates with a Windows 95/98/2000 or NT operating systems. Using a basic web browser, the DAS can be configured and controlled right from the computer. Current capabilities include network configuration, CD player-type control (stop, start, pause, next, previous), display of the current artist/album/song, and selection between your favorite playlists.

Since I am a Macintosh user, I employed the software Virtual PC from Connectix, which provided me with the proper OS. I already had a network wired between my upstairs office to my downstairs home theater, where the DAS-750 was hooked up. I use two screens on my workstation and used one monitor to access Mac files while the other monitor was displaying the Windows interface. Transferring music files to the DAS was a simple drag and drop procedure. I selected files from the Mac hard drive and dropped them right into the DAS folder inside Windows Explorer.

Once all the files were downloaded, the DAS became a jukebox, capable of playing all the archived music in playlists that I created. Music stored on the DAS can also be played on any networked computer using an MP3 player program (like WINAMP, Musicmatch, Windows Media Player, etc.). The DAS will also connect to an external CD player or changer to share music files over an Ethernet network. A major advantage of the networked approach is that any device on the network can see and access the DAS unit.

Software upgrades (from are made over the Internet (assuming you have a router for Internet access on your network). Just select the upgrade option from the front panel using the QuikSpin™ dial. Software upgrades also ensure that future audio formats will be accepted by the DAS-750.

Music Files
The DAS can store, organize and play a large collection of music from a variety of various sources (LP, tape, CD), not just MP3 files. When transferring data directly from a CD, tape or vinyl LP (separate phono preamp is required), archiving is performed in real time. There is no other option when recording an analog source, but it is far more efficient to encode audio from a CD using a computer with a ripping program (I use Sound Jam for Mac), which is generally three to six times faster. Once the PC rips all the tracks, it is a simple matter to transfer them to the DAS via the network.

Before moving on, a quick word about MP3 files. If you have downloaded anything off of Napster, Macster or, you know that not all files are created (or sound) equal. This is due to the bit rate at which they were encoded. Ripping programs have the option to encode at various bit rates. 128 kpbs (kilo bits per second) is the equivalent of 44.1kHz and should sound very similar (if not identical) to the original CD. However, these large files can be unwieldy when being passed around on the Web, so they are often encoded at lower bit rates, such as 56kbps or even lower. Moreover, if an artist is distributing these files for sampling purposes, he or she may not allow you to get the best quality file for free.

In addition to the bit rate of the file, you have to be concerned about transmission rates when getting files from services like Napster. Files are essentially being downloaded from other people’s computers. So when you download a file, the rate of transmission will vary greatly depending on that individual’s connection speed. Just because someone says they are transmitting on a T1 line doesn’t make it a reality. Before downloading files, set your download option to “ping” the other computer to verify the transmission speed. Not only do slow transmissions take a long time to download, but the integrity of the music file is often compromised.

Therefore, when downloading and preparing your playlists by computer, pay careful attention to the bit rates and integrity of each file. Otherwise, you may notice some dramatic and less than desirable results when the files are played back on the DAS through a sound system that will reveal far more flaws then the average soundcard. With the 20-bit DACs, the DAS-750 will perform on par with the best CD player. Only the source material might be an issue.

When a CD player is connected directly to a DAS digital input, then recorded and stored, serial copy management (SCMS) is employed, preventing a second-generation copy of these files from being recorded onto a CD-R/CD-RW. Moreover, the DAS detects copies of copywrited originals previously recorded onto a CD-R/CD-RW disc that employs SCMS and will not record those files onto its hard drive.

Making Playlists
The DAS-750 can be controlled from the front panel or from a networked PC. From the front panel, all settings and playlists are accessed using the QuikSpin™ dial and the built-in front panel display. The backlit electric blue graphical LCD displays artist, album and song information and device settings. The dial is used to select your options. You select your choice by pushing the dial. It was fairly intuitive, but when editing playlists, I found it to be much easier to edit and manage playlists from the PC.

When creating playlists, the order of the songs is determined by the way you add song files. For instance, if I want the songs to play in a particular order, I must add the songs to the playlist in that order. There is no way to change that order later on, except to re-create the playlist. Also, if I create a folder with all my favorite Bruce Springsteen tunes and move them all to a special Springsteen playlist, they will play in alphabetical order unless I move each file into the playlist in the order that I wish to play them.

Playlists are saved as .m3u files, which are essentially text files that are paths or links back to the original files that reside on the hard drive in various folders. Any number of playlists can be created, though only 10 can be assigned to a remote control (numbers 0-9) for instant access. A programmable Zenith remote is packaged with the DAS-750 for assigning playlists and providing basic playback functions (ie. Stop, Play, Next, Previous and Pause). All playlists are accessed from a PC.

I didn’t really like using the QuckSpin™ dial. It wasn’t that it was difficult, but when setting up playlists, you are constantly scrolling through various lists and it’s easy to get a bit lost, since the screen is only about three inches high. When you are creating playlists from the PC, it is much clearer as to which folders you are working with and in which playlist you placed various songs. Also, when working on the PC, naming folders and playlists is simple with the keyboard. Using the alpha-numeric keys in the DAS took a lot more time, as you had to dial up and select each letter/number.

I also got a bit hung up on the fact that I couldn’t change the order of the songs once I pulled them into the playlist. Hopefully, in the future, this can be remedied by a software upgrade that will be considered soon.

Music distribution over the Internet has indeed inspired some new and exciting products in just the last two years. However, this new revolution has been disconcerting to the more discriminating music listener, due to the quality of the files and the playback devices, mostly PCs and small hand-held Walkman devices. The DAS-750 enters a new phase, offering up a dedicated audio component for digital music files. It eliminates the negative attributes of a PC soundcard, which can induce noise and hum into audio playback. It also takes us a step beyond the CD changer. It is akin to a radio station in your own home. You don’t have to handle a CD library at all, once the music files are transferred to the DAS-750. Once stored into the DAS, any song can be placed in any number of playlists for instant recall.

If you make a lot of compilation discs for parties or collect tons of music off the Internet, you need to check out the DAS-750. It’s the ultimate archiving tool. For those of you who have avoided collecting MP3 files because you didn’t like your choice of playback devices, think again. The DAS-750 with its 20-bit DAC raises the bar on MP3 performance.
Manufacturer Lansonic
Model DAS-750 Digital Audio Server
Reviewer Kim Wilson

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