At a compact 1.69 by 3.15 by 0.71 inches and 1.24 ounces, the MP-800 fits easily in a shirt pocket, while the cord on the included earbuds doubles as a lanyard for easy portability. With its black plastic shell and silver trim, the unit itself isn't eye-popping, but it feels comfortable in your hand. Three buttons (power/play/pause, record/A-B loop, and FM) and a Hold switch line the top of the unit, and a four-way joystick sits to the right of the display. All of the buttons are small but tactile.
The player's streamlined design may be too bare-bones for efficient navigation. While a song is playing, pressing down on the joystick brings up options for adjusting the speed, the EQ presets, and the repeat/shuffle modes. To access the main system menu, however, you have to pause the song, then press and hold the joystick once to reach Music mode, then press and hold the joystick again to reach the main setup menu options. This frustrating navigation process would have been much easier with a dedicated menu button, and it wouldn't require much additional space.
MP3 and unprotected WMA files are transferred to the player through Windows Explorer. (Windows 98 users will have to install drivers from the included CD-ROM.) Along with digital music playback, the MP-800 features an FM tuner with which you can manually save up to 10 FM presets; disappointingly, there's no option for scanning and automatically setting presets. There's no seamless way to switch from MP3 to FM mode--you have to go through the laborious process mentioned above to accomplish this.
Pressing the FM button during MP3 playback activates the FM transmitter, which allows you to listen to MP3s over a car radio or home stereo without extra cables. The feature worked well on our home stereo, transmitting a clear signal from as far away as 30 feet from the receiver. Just remember to boost the volume to the maximum level on the MP-800 and to keep the earbuds plugged in if you're going to use this feature. The audio quality wasn't great in our tests, but it was static-free. The transmitter works on unused frequencies between 88.1MHz and 88.9MHz. The MP-800 also offers line-in and FM recording capability, and these files are saved in MP3 format at bit rates from 8Kbps to 256Kbps.
Despite a decent 90dB signal-to-noise ratio, music sounded only adequate with either the included earbuds or a set of full-size Koss UR-40 headphones. The five EQ presets (Normal, Live, Classic, Pop, Rock) made songs sound either flat or muffled. With an earphone output of 10mW per channel, however, music gets loud, even with larger headphones. In CNET Labs' tests, tracks transferred to the player at a rate of 0.42MB per second, which is just below average for a USB 1.1 connection. The 8.1 hours of continuous playback from the single AAA battery is also subpar.