Following models are no longer manufactured.

When it comes to audio performance, there's nothing small about Olympus's compact DM-550. Incorporating oversized stereo microphones, these models make it possible to capture the highest quality sound in any situation - whether you're recording a business meeting, an interview, or a musical concert.
The DM-550 from Olympus - Another breakthrough in compact digital recorders.
The DM-550 is compatible with extra-high-quality linear PCM (WAV) recording which boasts a wide bandwidth from 40 Hz to 23 kHz*1,providing you with the same high sound quality as music CDs. In addition to the CD-quality 44.1 kHz/16-bit mode, the DM-550 allows you to record with a 48 kHz sampling rate for higher quality sound that's even better than CDs.

With an improved S/N ratio, these stereo microphones are powerful enough to handle the demands of high-quality sound recording - even in the linear PCM format. With a 48 kHz sampling rate, linear PCM makes it possible to record a wide frequency response and accurately capture the sounds of real life.

The DM-550 comes with 4 GB built-in memory for up to 1065 hours of recording in LP mode.For even more recording time, a microSD/microSDHC card slot is provided, allowing up to 16 GB of additional recording.

Thanks to advanced DVM technology, microphone directivity can be switched between ZOOM, NARROW, WIDE or OFF mode as required.

The DM-550 is capable of recording and playback in three major formats - MP3, WMA and linear PCM (WAV). You can enjoy true-to-life stereo recording with full presence,as well as high-fidelity sound reproduction with a single compact unit.
The DM-550 is not only for recording, it also features superior music playback capability. The EUPHONY MOBILE offers surround sound with natural expansion for long hours of fatigue-free listening. Select the acoustical environmental setting from Natural, Wide, Power or OFF.

With the provided PC software, you can easily play and edit the sound data. Podcast data management is also possible easily.
Furthermore,updating to the Olympus Sonority Plus edition expands the capability such as MP3 encoding or CD-R writing for more versatile desktop sound enjoyment.

When activated, this assures clear, noise-free sound during playback. A Voice Filter is also provided to minimize unnecessary low- and high-frequency components for clearer voices.
Transferring sound files to and from your PC is easy using the provided USB cable. As an added convenience, with the USB cable connected to your PC, you can even recharge the AAA-size Ni-MH batteries (supplied) via the PC's USB port without removing the batteries from the recorder.