Tascam 564

Tascam, the originators of the Portastudio concept, which is now almost 25 years old, have taken a fresh look at the format for the '90s, substituting the digital MiniDisc medium for the analogue tape which has served home recordists so well, and adding a clutch of brand‑new features. Hugh Robjohns indulges in a little 4‑play...

Whatever did we do before Tascam invented the first Portastudio? Fully integrated 4‑track recorder‑mixers seem such a fundamental part of so many home studios these days that it makes you wonder what we would do without them. Of course, the cassette‑based systems have always had their limitations, with restricted dynamic range and frequency response, and the inevitably rapid build‑up of tape noise, but these have all been gradually improved over the years.

However, the widespread use of Compact Discs and the popularity of NICAM television have made us all aware of the benefits of digital audio, and have created new expectations of quality and convenience, which the humble cassette recorder can not really fulfil. However, the digital MiniDisc medium certainly can, and with the Data Disc format, it becomes almost a straight plug‑in replacement for the 4‑track analogue cassette, but with a host of extra advantages thrown in.

The idea is not entirely unique, of course — you'll recall that Yamaha's MD4 digital multitracker was reviewed in the September issue, and Sony are planning to release a similar product shortly. But, as always, Tascam have some unique angles which they hope will give their new product, the 564 Digital Portastudio, the edge over its rivals. The good news is that the specifications for the MD data format are quite rigorous, so a session recorded on the 564 should be playable on the other manufacturers' machines: it may thus be possible to exchange disks and add your expert overdubs to your friends' recordings!

Concept

The basic design of the 564 follows the familiar pattern of previous Portastudios. It has four input channels (two with insert points) capable of accepting microphone or line‑level signals (electronically balanced on XLR and jack), all with 3‑band EQ and two post‑fade effects sends. It also has two stereo inputs with 2‑band EQ, and two simple stereo effects returns (quarter‑inch jack connections). The monitoring system has facilities for a 2‑track stereo monitoring return (phono sockets) for easy checking of your master recordings.

The 564 has ample output facilities too. The stereo outputs from the mixer's master fader and the monitoring sections (all on phonos) are accompanied by outputs from the two effects sends, a headphone socket, and a cue signal output (all on jacks), plus the four discrete outputs from the MiniDisc transport (phonos again). The latter will allow mixes to be made through an external mixer, of course. There's also an SPDIF socket at the back, which provides a digital output from tracks 1 and 2, and the familiar trio of MIDI connections.

The mixer section of the 564 is very much par for the course, but what about the MiniDisc transport — what does that offer? Well, fundamentally it can be thought of (and used in) exactly the same way as a traditional cassette system, except that the recording time is rather longer, at 37 minutes (with a maximum of five separate song recordings per disk), and there's no waiting around for the tape to rewind. There's also no need to sacrifice a track for timecode, because the system has built in MIDI timecode and MIDI clock facilities which are derived directly from the ATIP (Absolute Time In Pre‑groove) track information embedded within every blank MiniDisc.

The 564 is a wonderful machine — I'd forgotten how much fun a Portastudio could be.

Tascam's MiniDisc mechanism is capable of very fast track access, which means that it is possible to make it hop about replaying isolated sections of recorded audio in any order you choose. This is an extremely useful facility because it allows sections of a song to be marked with index points (verse, chorus, bridge, and so on) and then replayed in any order, in a similar way to how a hard‑disk editing system works. When you've found the best sequence and combination of sections, it's even possible to copy, move and insert the relevant material to create a new physical recording of the complete song elsewhere on the MiniDisc.

This process of bouncing audio to a different part of the disk is called 'Bounce Forward' in the Tascam vocabulary, and it is a rather powerful feature. In addition to the song‑construction process just described, it also allows a sophisticated version of overdubbing: once you've recorded four tracks of material, these can be sub‑mixed to a stereo pair of tracks, which are copied in real time to a new part of the disc (no need for dubbing off onto another stereo cassette!). Two extra tracks can then be added and the process repeated. The disk, with a capacity of 140Mb, will hold up to five songs at a time, so in theory you could build up a 12‑track recording with the signal never leaving the confines of the 564.

In fact, once you're happy with your bounced‑forward mix, you can erase the original song, allowing almost unlimited bouncing and overdubbing within the five‑song capacity of the disk. One point to bear in mind, though, is that although the MiniDisc is a digital format, it is not immune to generation loss, because in order to get 37 minutes of 4‑track audio onto the disk, a 'lossy' data‑reduction system called ATRAC (Adaptive Transform Acoustic Coding) is used. To cut a long and complicated story very short, this process tries to work out what can and can't be heard by the 'average' listener (taking into account frequency and temporal masking effects), and discards the bits of the sound that it thinks we won't miss. In general, the system works well, but most people can hear a small difference in a straight A/B comparison between some original material and the ATRAC‑recorded version. This is unlikely to be a problem in the context of typical home studio multitracking projects, but repeated song and track bouncing will cause noticeable degradation to the earliest recordings after about four or five passes. The most obvious artifacts are a rise in the noise floor (better than, but similar to that of a cassette system), loss of low‑level detail (don't record reverbs, if you can help it, on the early generations), a gritty harshness and, depending on the material, a loss of the highest frequency extremes.

Don't get the wrong idea here — the perceived quality of the MD system is streets ahead of any analogue cassette multitracker, but it is not in the same league as a linear hard‑disk system or a full‑blown Sony 48‑track DASmachine! Then again, neither is the price...

Operation

Using the 564 is pretty intuitive, although some of the editing commands can be a little confusing — for example, my colleague managed to erase a section of a song without even realising it until it was too late (bet he won't do it again, though)!

Setting up the mixer side of the machine is trivially simple. The balanced XLR and quarter‑inch jack sockets are wired in parallel, so either can be used for signals between ‑65 and ‑10dBV (there is no provision for phantom power). The input amplifiers are possibly not the quietest I have ever heard, but are perfectly up to the job of handling close‑mic'd voices and acoustic instruments. Unfortunately, the faders are not marked with a unity gain position, and this can cause problems when bouncing tracks, as the overall gain can creep up or down, risking overload or extra noise respectively.

A slide switch directly below each input gain control selects what signal source is passed through the channel strip. When the switch is set to its left position, the input is the mic/line socket, while in the centre position, it handles the corresponding replay track from the MiniDisc, for mixdown purposes. When the switch is in the rightmost position, the channel still controls the MiniDisc replay, but the mic/line socket (after the gain trim control) is routed directly to the main stereo output fader, allowing extra tracks (MIDI keyboards, for example) to be incorporated during mixdown.

The EQ sounds OK, with sensible turnovers for the high and low shelf bands. The mid‑band is sweepable over the range 250Hz to 5kHz, covering the most critical part of the spectrum nicely, but unfortunately there is no EQ bypass switch to allow comparison between the original and equalised sound. The two auxiliary sends are fixed as post‑fade effects outputs.

At the bottom of the strip is a pan control which routes the signal to the stereo master fader. The MiniDisc will either record in stereo track pairs from the master stereo mix buss (i.e. left buss to tracks 1 or 3, right buss to tracks 2 or 4), or all four tracks directly from the first four channel faders.

The two stereo input channels (inputs 5&6 and 7&8) are similar to the first four inputs, except that there's no input level trim control (rather frustrating!) and the EQ is simplified to just top and bottom shelf bands. The pan pot is replaced with a proper balance control, and the routing switch is different, in that it routes the signal to either the main stereo master fader, or the cue mixer. The latter is a separate mixer section which has individual level controls combining the outputs of the four MiniDisc tracks for monitoring purposes. By routing the stereo channels to the cue mixer, you can audition MIDI keyboards (or other 'virtual' tracks) alongside the pre‑recorded acoustic tracks. A third position of the switch simply mutes the stereo input channels.

The stereo effects returns are very simple, but do boast a level control, unlike the stereo input channels! The routing is identical to the main stereo inputs, except that the output to the master fader is labelled L‑R, instead of Main (as it does not pass through the fader).

Monitoring is flexible and obvious, with buttons to select monitoring of left or right stereo mixer busses (pressing both gives normal stereo), AFL buttons for the two effects sends, a cue mix monitor button, and a 2‑track return. These buttons are not interlocked, so you can listen to everything at once if you want to!

To sum up, setting up the desk for recording is simply a matter of adjusting levels and EQ for the acoustic instruments and vocals, routing the MIDI keyboards and drums to the cue mixer, doing the same for the reverb and the like through the effects returns, and then arming the appropriate tracks to record.

The Transport Controls

The MiniDisc mechanism itself is mounted on the left‑hand side of the 564's case, which means that there must be at least three inches of free space here to allow discs to be inserted and removed. Although it would have been nicer if this mechanism was at the front of the 564, it is actually quite a large unit and would not fit under the front because of the control surface 'raking'.

At the top of the front panel are bargraph meters for the four MiniDisc tracks and the stereo main outputs. The meters all cover a 45dB range, but the resolution is poor, as there are only seven LEDs in each bargraph. The four meters associated with the MD tracks each have a red Record LED, to show when each track is actually recording.

The process of bouncing audio to a different part of the disk is called 'Bounce Forward' in the Tascam vocabulary, and it is a rather powerful feature.

Below the meters are Safe/Direct/Bus slider switches which determine the record source for each track. Direct picks up a feed from the corresponding input channel's fader, while Bus picks up the left or right stereo output. The Safe position is actually the output of the corresponding track, as when the disk records, it has to re‑record all four tracks simultaneously, by replaying the original material and then either re‑recording it in the same place, or replacing it with new audio material.

At the front of the control surface are a set of transport keys, including Stop, Play, Record, and Index skips to jump forward and backwards or return to the top of the current song. To the right of these is a jog/shuttle wheel, where the outside ring is used either to confirm menu actions or to scroll through the contents of an MD (although I found this very hard to use because of the characteristically garbled soundbites — similar to a spooling DAT). The inner wheel is the jog wheel, and this is used for data selection on the menu pages and to locate and trim editing points and index markers.

Falling nicely to hand around the wheel are four buttons. These are used to set, Trim and Clear index marks, and to control the non‑destructive song‑editing mode. The remaining buttons are used to control the various operational modes, such as repetitive looping between index marks, varispeed, punch‑in and out points (with a rehearsal mode), and so on. When any function is activated, by pressing one of these buttons, a help screen is presented on a clear two‑line LCD panel immediately above the jog wheel, and the instructions make it very intuitive to set the machine up to do whatever you want. In the few cases when I didn't quite achieve what I wanted the first time, a little trial and error quickly solved the problem and I didn't really need the manual at all (although it's very thorough and clearly written in the usual Tascam way).

The automatic punch‑in system is intriguing. The system allows in and out points to be defined (and trimmed) and then performs rehearsal cycles between these points to allow the punch‑in to be perfected. To record the punch‑in, the user must select a take number first; up to five takes can be recorded and stored separately, assuming that there is sufficient space on the disk. These takes can then be auditioned and compared, the best one being retained and the rest discarded — a very handy facility indeed.

Another particularly nice feature is the ability to trim and then name index marks so that, when a song has been recorded, each section can be identified accurately (there is a limit of 20 index marks per song). Trimming an edit is very simple, although it takes practice to make sense of what the short looped burst of audio around the current Index mark actually is! When you've found the correct start point, the end can be marked in the same way and the section given a name. The system has a selection of useful preset labels, such as count‑in, intro, hook, verse, bridge, and so on, although you can also type in your own legends.

These labels should be really useful in Index Programme mode, where the indexed sections can be copied and moved around non‑destructively. In this mode, the top row of the LCD window shows the current step in the programme with the number of the selected index, while the bottom line displays the complete song running time — but nowhere is the name of the selected section displayed. So unless you carefully noted down the section names and their associated index numbers, you wasted your time in labelling them in the first place! I have to say that I was rather disappointed with this aspect of the software design.

Assuming that index points are marked accurately, the index editing mode is brilliant (I found that marking indexes on the fly produced perfectly acceptable results, and was often more accurate, and certainly much easier, than scrubbing the audio). In all the edits I made, there were never any clicks or holes, and after I bounced the audio down to another song, it was impossible to tell that the material was originally in a different order! This facility is excellent and allows lots of experimentation and creativity in constructing a song.

Summary

The 564 is a wonderful machine — I'd forgotten how much fun a Portastudio could be! It makes an excellent 'musical notebook': just like the original Portastudios, but with the advantage that it can potentially make recordings of a high enough quality to copy straight onto a professional system! The audio quality of the MD format is a major attraction in itself (at least in the context of its price and the alternative cassette‑based systems), as are the virtually instant locate times, the bounce‑forward overdubbing system, and the non‑destructive song editing functions. The bounce‑forward technique for overdubs is a very safe and simple way of building up recorded parts, and the ability to instantly go back to the previous version(s) and start again is likely to be very useful indeed.

There are some shortcomings in one or two areas of the mixer — such as the lack of an EQ bypass button, no level trims on the stereo inputs, no unity gain marks on the faders — but on the whole, the mixer is well designed and does its job without problems. The control menus and general operation are very easy to understand, and the menu system guides the user through most operations smoothly. It's a shame that the song section labels cannot be seen when making sequence edits, since this is when they would be most useful, but apart from that, the function itself is excellent and the editing facilities in general are superb.

Overall, this Portastudio deserves to do extremely well, and I'm sure it will meet the needs of a huge number of home recordists perfectly. Definitely one to check out at your local music store.