The MD4 uses the Mini Disc (MD) format removable discs to record up to four tracks of digital audio. Maximum recording time is 37 minutes in four-track mode or 74 minutes in two-track, stereo mode. Priced at $1,200 retail, the MD4 combines mixing functions and multitrack recording in a small, portable package.

Frequency response is 20Hz. to 20kHz. at a sample rate of 44.1kHz. There is .01% total harmonic distortion with low noise and no flutter or wow. The MD data disc can be erased and recorded one million times and you may track bounce without degradation. There is the ability to combine all four recorded tracks down to a stereo mix and record it back to two tracks... (like having six tracks instead of four). The MD4 also has direct outputs for each track so you can externally mix tracks with another mixer. Another good feature is the rehearsal auto punch and auto locator with which you can precisely punch in and out at exact locations in your song. There is also a vari-speed function of + or - 6% for adjusting playback or recording pitch. For external synchronization, the MD4 has a MIDI out jack that transmits either MIDI Time Code (MTC) or MIDI clocks which will control your sequencer or computer music system.

Since the MD4 can run your sequencer, it is important to know that the MD4 is capable of Cue List Playback. You can arrange up to nine different cues to playback in any order. This would allow for "flying" vocals or live instruments around your song the same way you manipulate synth performance data in your sequencer. The Program Playback function allows you to compile a program of up to 36 songs to play in a specific order.

Just like its analog counterparts, the MD4 has a four-channel mixer with a three-band equalizer, variable gain, an aux send, pan pot and fader on each channel. There are plenty of input and output jacks on the unit to patch all your favorite effects, DAT mixdown machine and headphones. You can record up to 255 songs on a single MD disc with each song "titled" from the front panel controls.