Michael R Goolsby (firstname.lastname@example.org)
In response to the request for input on MD multitracks, I will say that I have enjoyed using the Sony MDM-X4 for the past six months. Having extensively researched and auditioned all three multitracks available (Yamaha, Sony, and Tascam), I made the choice that best suited my needs.
The Yamaha was out pretty early. Although balanced inputs is not essential for short mic cable runs, it didn't even offer them. Also, it had no separate stereo inputs, offering the fewest ins and outs of all three. It also featured an older ATRAC version. All in all, an okay system for a low price (typically $700).
The Tascam is one heck of a machine. The most ins and outs of all of them. It also offers digital out (the only one), auto-punch in and out, and lets you "audition" up to five takes (pretty cool). Of course, it's also the priciest - $1250. Still, it had some problems that didn't seem to make much sense. First, ATRAC 2. Yes, you read right - 2 (and that's according to their info on the unit). Also, it is not capable of recording onto standard audio discs -- it will only playback. It will only record on DATA discs (beware, the Yamaha also has this limitation, but there is some sort of "patch" that will convert it so that it will indeed record 2 tracks on standard audio MDs, as makes sense). Finally, there is a limitation of 5 "songs" (or song tracks) per MD. Their reasoning was that an MD Data disc only holds 37 minutes of 4-track music and nobody would therefore need more than about 5 tracks.
The Sony is middle of the two others in price and features. It has two balanced XLR inputs and 2 unbalanced quarter inches. It is compatible for recording with both DATA and AUDIO discs (naturally, only 2 tracks on the latter). It has no digital out, but it should be noted that even the Tascam's digital out is 2-track stereo. Any 4-track material would have to be mixed down to 2 before going out digitally. In addition, the Tascam's digital out is coaxial. The Sony has 4 mic/line inputs and another stereo pair input. It features ATRAC 3.5, which makes more sense. The display is easy to read and the meters clear and detailed. (Don't imagine that this will replace your home deck however. I sold my MDS-302 thinking it would, and then turned around and got a MDS-JE500.) And for $885 (from Full Compass, typically $950 most places), it's a great machine.
I have used it to record and mix numerous projects. The ability to READ from a track and WRITE over it at the same time is simply incredible. Enthusiastic MD users who enjoy mixing should consider this unit.
(Further comments from Michael)
You can copy (bypassing ATRAC) a track onto the same disc. Useful if you want to experiment with a track while preserving an original version of it.
The MDM-X4 allows you to both READ and WRITE to the same track(s) simultaneously. This permits you to, for example, mix down four tracks onto two tracks without having to have 2 free tracks. Just get the mix you want and set two of them two record. The two tracks that are recording also will record what is being played back on those two tracks.
All of the editing features available for 4-track data discs are available using 2 track audio discs -- use just simply only get 2 tracks. I've done DJ mixes using audio discs which easily allows music to be "layered" -- one song on top of another during transitions. This Halloween, I also put together a disc of sound effects using this technique. All of the initial material was recorded "live" with either a portable MD or the MDM-X4. For the mixdown, I first put down the thunder and lightening sounds. Then I layered various "monster" sounds, screams, music, and other sounds. Probably 10 or so "overdubs" in some places, all using a standard audio MD.
The MDM-X4 offers a separate stereo input (playback tracks 5 and 6) in addition to input/output tracks 1-4. This means that if you want to input a stereo source such as CD, you don't have to use up two of your 4 recording tracks doing so. Likewise, you could conceivably connect the stereo output from a second mixing board with as many mics as necessary, though they would have to be mixed in onto your four recording tracks.
(Yet more comments from Michael)
According so Sony documentation, TRACK or SONG COPY on the X4 does indeed bypass ATRAC -- that is, the data is copied verbatim rather than music undergoing another decoding/encoding process. In fact, this feature does not occur in real time. I have noticed copy times of roughly 2 to 3 times longer than the duration of the material copied. Note however, that copying can only be done on the same disc. This feature makes plenty of sense if you consider the purpose of copying a track or song would be to allow one to experiment with a mixdown while preserving an original. Since the MD drive is a MD DATA drive, I see where this would also be not only plausible but expected.
Someone asked if the additional stereo input made it more of a six-track recorder. No, not really. You can still only record onto 4 tracks at once. However, the additional stereo input (playback tracks 5 and 6) can be mixed onto any of the first four recordable tracks.
Someone else asked, in regards to the unit being fully compatible with standard 2-track audio discs, if these two tracks were L and R or MONO. The answer is, well, either. All four recordable tracks (or 2 if using audio MD) have a gain (trim) knob, input (MIC or LINE) switch, three bands of EQ, an effects loop knob, a channel selection switch, and of course a PAN knob. Therefore, each track can have its own spatial placement. For standard MD audio disc recording in stereo, just pan one channel hard left, and the other hard right. Easy.
An example of recording a simple vocal and piano song onto standard audio MD: Two mics would be place insided the piano -- track 1 panned hard L and track 2 panned hard R. The vocalist would use a third mic, going into the third slot on the board, but then ASSIGNED to both tracks 1 and 2 with middle (flat, or "mono") panning, putting the vocal right down the middle where it belongs. The only trick to this method is finding the right mix prior to recording. If you record onto a DATA disc, you can simply record onto a real track 3 and then mix down for balance and eq later. I personally don't mind the first method with MD audio if it's really this simple.