Features: ATRAC 3.5 Uses MD Data discs. Each channel has: Trim pot, Line/Mic selector, Aux -10 to 10 pot, high, mid, and low eq pots, assign push buttons, one for chans 1&2, 2nd for 3&4, a stereo pan pot, a trim fader from 0 to 10. There's also a 5&6 vertical column with all of the above single channel stuff, plus some extras, and a "Master" vertical row. Inputs are XLR for channels 1&2, 1/4" for the rest (prototype had 1/4" for all inputs), plus 2 for AUX, outputs look like 4 X 1/4" for Disc1 to Disk4, two stereo inputs for return1 and return2. On the back there are MIDI in, out, thru connectors for MTC and MMC. The deck can be controlled with MIDI sequencer software. To the right of the Sony, there is an electronic display, power on switch, top, left, right, play, and stop buttons, and red record button, plus about 20 white buttons for record channel select (1-4), 8 locate buttons, then there's a jog/shuttle wheel. Has digital copy (bypassing ATRAC codec) between tracks. Can bounce 4 tracks down into 1 or 2 on the fly. -Ted Matsumura

Links:

• Harmony Central also has info on this unit.
• A user's impressions of the Sony MDM-X4.
• Another user's comments and comparison of the Sony MDM-X4 multitracker with the other multitrack machines.
• Mike Rivers made some comments about MD Multitrack Recorders at a recent Consumer Electronics Show.

Bugs: One user has found that Sony's MDM-X4 units have a glitch that causes track delete to frequently malfunction.

Dale Greer ([email protected])

For those of you who purchased early production runs of the Sony MDM-X4 4-track portastudio, you may have discovered a few firmware bugs that 1) won't let you eject stereo discs under certain circumstances and 2) prevent track deletion under certain circumstances.

These units all seem to have an EPROM chip inside with a decal that identifies it as firmware version 1.20 (part no. 759-467-95). Sony U.S. will fix the unit if you send it to a repair center, but they will charge you $150 for shop time. If you are fairly handy with srewdriver, though, the EPROM upgrade to Firmware version 1.30 can be had for free, and the new chip has fixed all of my unit's bugs.

To check what version your deck has, remove the two black screws above the output jacks on the rear panel and the 10 or so screws on the bottom of the unit (Caution: remove only the bottom srews that have arrows pointing at them). The top then lifts off like a clamshell (do this carefully so as not to unplug jumper cables), and you can read the deccal on the chip. I reccomend you wear a static strap while doing this, as the inside is loaded with surface mount devices and quad flat packs.

To get your upgrdrade (part no. 875948693), call Sony U.S. Professional at 1 (800) 686-7669 and ask to be transferred to a support engineer or technician in California. (I say this because they seem to want to charge you for the chip if you talk to someone at Sony's repair center in Itasca, Illinois, or Teaneck, New Jersey.) The guys in California consider this a "software" upgrade and will ship it out FedEx at no charge.

Notes: Sony has updated this unit with the MDM-X4 MKII. According to the new Musician's Friend catalog (www.musiciansfriend.com), the MKII model has "improved compression (ATRAC 4.5), linking capibility, instant start, and 20-character titles (7 in the older model)." Musician's Friend sells the MKII model for $749.94. Available elsewhere as low as $700. Phil Gartman points out Sony's MDM-X4 MKII page.

Reviews:

User Manual: MDM-X4

Service Manual: MDM-X4