Sony's nomadic Walkman personal stereo tribe has spawned a whole new family of products that use the power of the PC to compile high-quality music on the move.

The funkiest baby is a diminutive Network Walkman which goes by the enigmatic epithet 'NWMS70D'. Its 54g titanium body can store tracks from up to 11 audio CDs — or the equivalent amount of data — on an imbedded 256MB flash memory and removable Memory Stick Duo, a proprietary Sony solidstate memory module.

When it launches in April, the NWMS70D will carry a suggested retail price of £279.99 and be aimed at "the PC-based computer-literate music fan and technology enthusiast who must have the smallest," according to Sony's marketing bumph.

The Network Walkman comes with Sony's SonicStage software — as do all the new Walkman models — which runs on a PC and enables CD, MP3, WAV, WMA and PC data to be transferred to the device via a USB port on its base charger.

SonicStage software includes Amtrac, Sony's proprietary compression and encryption codec, and all music to be played on the new Walkmans is converted into this format. Sony officials say Amtrac provides much better quality than MP3. Oh, and it has the added benefit (for Sony) that files in Amtrac format can't be emailed, thus preventing illegal music file sharing. In fact in some applications, SonicStage helpfully deletes Amtrac format files from your PC once a transfer has been successful.

Mini Disc, Sony's half-sized recordable CD format, was 10 years old in 2002, but it's already hearing the patter of tiny platters in the shape of new Net MD Walkmans, that enable you to copy CDs, MP3s, WAVs, WMAs and so forth on to Mini Disc — via Atrac, of course.

The Walkman tribe also includes a growing family of Atrac CD Walkmans that first pitched their tents in Las Vegas at the Consumer Electronics Show in January. They can play CDs, MP3s and CD-Rs/RWs, but we're not allowed to tell you more about them until 5 March.