The Karma's excellent Windows-based Rio Music Manager 2.0 software combines a straightforward interface with a competitive selection of autosynchronization, music-playback, ID3-editing, playlist-creation, and file-transfer capabilities. It can also rip audio CDs to fixed and variable bit-rate MP3 and WMA, as well as the open-source &siteid=7&edid=&lop=txt&destcat=ex&destUrl=http%3A%2F%2Fwww%2Evorbis%2Ecom%2F" target="_blank">Ogg Vorbis and FLAC (Free Lossless Audio Codec). The latter is especially prized by audiophiles since it sounds exactly as good as the original CD, at a smaller file size. Music Manager 2.0 also includes an auto-update function that lets you upgrade the Karma's firmware with just a few clicks.
Rio also throws in Rio Taxi software, which lets you use the device as a portable hard drive to transport data files and music tracks between any PCs that have the app installed. In January 2004, Rio plans to release an enhanced version of RealOne designed specifically for this player, as well as Macintosh software and drivers. (Linux and OS X users can use the Ethernet port to transfer files to the device, but those operating systems are not officially supported.)
According to Rio, the Karma produces a signal-to-noise ratio greater than 95dB at its very loud power output (about 60mW per channel at 16 ohms). This translates into more than enough power to cleanly drive most full-size dynamic headphones to top volumes. The bundled Sennheiser MX-300s sound great through all registers, especially in the bass range. But like most buds, they can be tricky to fit into some listener's ears and provide only moderate isolation from external noise. Sound improved when we used our Shure E3c reference headphones.
As you'd expect, the Rio Karma's 480Mbps USB 2.0 interface produced blazing file-transfer speeds. On average, it took about 20 seconds to download a 100MB collection of nine music files to our test unit, for a file-transfer speed of 5MB per second.
Another strength is the Karma's long-lived rechargeable lithium-ion battery. Rio claims that the device will run 15 hours on a charge--about twice as long as the iPod. Our tests confirmed this.
Getting the Karma's network interface to work took a little more effort than we would have liked, but once it was up and running, it purred along. With the device in the cradle and connected via Ethernet, we were also able to perform file-upload, synchronization, and device-management functions on the remotely attached player. But the same files transferred more slowly than expected, at 0.53MB per second (about 10 times slower than via USB 2.0). Rio plans to eventually use this same interface to add the ability to stream music from a player to other devices attached to the same network. The company will also add a remote-control Web interface so that you can control the unit from any networked PC while it's attached to your stereo (making the device a de facto digital audio receiver). At that point, the device's Ethernet compatibility could become a major asset.