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Fostex DMT8

Digital Multitracker By Paul White
Published December 1995

Paul White visits the future of home recording, where tape heads never need cleaning, cassettes never jam and mistakes can be undone at the touch of a button.

Our recent product preview of the Fostex DMT8 disk‑based multitracker sparked off more interest than Nick Leeson's bank statements, but what really impresses me is that Fostex already have the finished models on their way to the shops — this time there's no interminable waiting for vapourware to condense! Though it doesn't offer anything new in the way of technology, or even features, the DMT8 attains a high coefficient of uniqueness due to its ferociously aggressive price and its simple, deliberately cassette‑like user interface.

Packaged to look and feel as much as possible like one of Fostex's existing multitrackers, the DMT8 is a dedicated 8‑track digital recorder based upon a 16‑bit, 44.1kHz sample rate system, offering simultaneous recording on up to four tracks. The storage medium is a 540Mb internal IDE disk drive which can provide a recording time of around 12.5 minutes (for 8 tracks), just a couple of minutes less than you'd get from a double speed cassette multitracker. Recordings can be backed up to DAT via the machine's optical connectors, which takes around 45 minutes, but there is no apparent means of extending the recording time by adding an external drive or by increasing the size of the internal drive; an obvious limitation. No digital phono S/PDIF sockets are fitted but an inexpensive optical‑to‑phono adaptor is available from Fostex.

Though designed to operate much like a cassette multitracker, the DMT8 offers additional random access features unique to tapeless systems — such as cut/copy/paste editing and, perhaps most importantly, undo. There are no virtual tracks or playlist‑type edit features, however, and the maximum recording time is fixed at 12.5 minutes regardless of whether you fill up only one track or all eight. The editing facilities are non‑destructive — you can always undo the last move you made, and as I understand it, part of the disk is used for temporary file storage, so if you intend to do a lot of editing, then it pays to leave a couple of minutes of disk space unused.

A jog wheel/shuttle dial is fitted for accurate edit point location and there's an Auto function that gives you an autolocator, auto return and play, and auto punch in/out with rehearsal mode and foot control option. This works very like its cassette counterpart, and to make life easier for those using sequencers, the DMT8 can transmit MIDI Clock with Song Position Pointers (via a 32‑point internal tempo map), as well as MTC (MIDI Timecode) and MMC (MIDI Machine Control), making it possible to control and synchronise an external sequencer. Moreover, the display system can be switched to read bars and beats (as defined by the internal tempo map) and there's a built‑in metronome, both of which make cut‑and‑paste editing easier as you can work in precise musical bars. Some means of importing tempo map information directly from a sequencer would have been a huge improvement over having to do everything manually, but at least the friendly operating system makes this process as painless as possible.

The DMT8 is a self‑contained system with its own built‑in mixer. This features 2‑band sweep EQ on each of the eight main channels, insert points and mic inputs on the first four channels, and up to 22 inputs (if you count the returns) on remix courtesy of a semi in‑line format. Four subgroups allow up to four different mixes to be recorded to disk in one go, and the two auxiliary sends are centre‑off types that can be fed from either the main or sub channels.

Package Deal

Measuring just 568 x 121 x 432mm, the DMT8 sits comfortably on a desktop. The layout follows the convention of having the mixer section to the left and the tape/transport section to the right — except, of course, that this unit has no tape. Even so, the display, transport keys and track arming buttons are so tape‑like that it's hard to believe there isn't a tape whirring away in there somewhere. As the DMT8 has the facility to store a tempo map, editing can be carried out to bar and beat locations rather than simply to time locations which, in a musical context, is generally more preferable.

Providing you have enough free disk space, the last edit you make can be undone, which is something tape can't offer. If, however, you don't have enough free disk space to hold the undo information, then you get a warning which tells you that your edit will be irreversible. The basic edit types are cut, copy, paste and erase, and to ensure a smooth transition between edited sections, a 10‑millisecond crossfade is automatically generated. In the event that you try to execute an edit that requires more disk space than you have left, an 'over' indicator will tell you by how much you're trying to exceed the remaining disk space, so that you can plan a more economic edit. If you end up with so many edits that the system has no room to cope with any more (around 250 max), you can backup your song to DAT via the optical port and then reload it; this prevents the hard drive from becoming too fragmented. Backing up takes four times the duration of the song length you're saving, and reloading takes exactly the same time. In addition to the audio, backing up also saves the relevant Setup data.

All the user information comes via a large plasma display which provides bargraph metering, record status indication, location time/position, and additional dialogue for information or warning. Six editable time memories can be used to handle autolocate, auto return and auto play, as well as auto punch‑in/out. Furthermore, the Locate key has its own memory, which is very useful when you want to keep coming back to the start of any section you happen to be working on. As with most Fostex auto punch‑in/out systems, the DMT8 includes a Rehearse mode which lets you monitor the effect of a punch‑in without actually committing it — once you are happy with it, you can go into Take mode and do it for real. A pre‑roll value can also be entered so that the machine starts a few seconds before the intended punch‑in point.

When sending MTC from the DMT8, all formats are available — including 30 drop‑frame — and the MTC may be offset by up to six hours from the absolute time value (presumably for the benefit of people who take a long time to get their fingers around their guitar chords!). As hard disks can access any part of the stored audio data almost instantly, Fostex have employed some trickery to make the transport more tape‑like and this includes the shuttle wheel, which makes it possible to fast cue the audio at up to 20 times actual speed. You can also hold down a wind or rewind button when the machine is in play mode to fast cue forwards or backwards. The inner wheel is used to find precise locations, right down to frame and sub‑frame accuracy. As you move the inner wheel, the audio is scrubbed, and at slower scrub speeds a short section is looped, which makes it easy to find edit points on the beat.

When you fast wind the audio, a deliberate slowing of pace has been built in, so that you end up zipping through the recording at about the same rate as a DAT machine in fast wind. Without this feature, the disk would go immediately to the start or end, giving you no chance to find an in‑between point. Once you've stopped the audio somewhere close to where you desire, you can use the jog/shuttle wheels to home in on the exact spot you are seeking.

The transport keys themselves look exactly like those found on a typical tape machine — there's a red Record button and grey buttons for Play, Stop, F Fwd and Rewind. By pressing two keys at a time, you can also replay the clipboard contents or jump to the start/end of your song. Track arming buttons below the display work in conjunction with the Record button to activate specific tracks, just as you'd expect, and pressing the Record button on its own switches any armed tracks from disk monitor (I nearly said tape monitor) to input source monitor status. In ready mode, the record LED and status LEDs flash, and in record mode proper they stay illuminated — just like a tape machine. Because hard disks don't have write‑protect tabs, the equivalent function is provided in software within the Setup menu, but you cannot protect your recording on a track‑by‑track basis — it's either all write‑protected or not, which I feel is a missed opportunity.

...the Fostex DMT8 is every bit as easy to use as a cassette multitracker...

The Setup menu is where you set the time signature and tempo of the tempo map, and where the internal metronome can be turned on and off. The metronome signal itself comes up on Sub channel 8, where you can control its level. You'll also find the DAT load and save routines as well as disk formatting in the Setup area alongside pre‑roll time, MIDI sync out selection and frame rate, MTC offset, and the previously mentioned record enable/disable. Once you're in Setup mode, the jog wheel can be used to navigate through the various screen pages and the Yes/Execute key is used to confirm entries when values have been changed — all pretty standard stuff.

Mixer Basics

The DMT8's mixer is basic by studio console standards, but it still has most of what you need to make good recordings, not least being the eight separate 'tape' outputs that let you route tracks to an external mixer instead, if you so wish.

Each of the eight mixer channels comprises a main Channel with EQ, and a Sub channel (normally used for monitoring during track laying), which has just level and pan controls. Having said that, there are two aux sends for use with effects and these work from a centre zero position, providing a send from the Sub channel when turned anti‑clockwise and from the main Channel when turned clockwise. The Sub inputs can be used as conventional line inputs at mixdown but only the first four Channels have mic inputs, and these are on quarter‑inch jacks with no phantom power. The four mic/line channels have insert points on stereo jacks and at the head of each Channel is a slide selector switch; this determines whether the channel is sourced from the Track or from the Input jack, rather like the Flip switch on a typical in‑line mixer.

Wrongly described in the manual as a 'parametric equaliser', the EQ section comprises two sweep equalisers, the upper of which covers the range 1kHz to 16kHz and the lower of which spans 60Hz to 1kHz. Up to 15dB of cut or boost is available for tonal correction, but there's no EQ bypass switch.

Routing is accomplished by means of a 3‑position slide selector switch and the Pan control. As on a conventional mixer, the switch selects the Group pair to which the signal is to be routed and the Pan control steers the signal between odd‑ and even‑numbered Groups. This mixer has just four Groups, each with its own master level control and a Left/Right routing button for use when mixing. The third position of the Group selection switch is a centre off, which serves instead of a mute button, but there is no Solo system of any kind. On the first four Channels, the Trim slider next to the main channel slider is used to set the mic/line input level; the same jack copes with both mic and line inputs. To keep the routing simple, there's no direct left/right routing — all the Channels are routed via the Groups and each Group level control has an adjacent button, used to patch the Group into the stereo mix.

Simplicity reigns in the master section of the mixer but there are two stereo effects returns which can be routed to one of the available Group pairs as well as to the main stereo mix; Aux 1 can feed Groups 1/2 or Left/Right, while Aux 2 can feed Groups 3/4 or Left/Right. Separate level controls are provided for the control room and headphone outputs, but although the Phones control has a staggering amount of level in reserve, it also picks up rather a lot of interference from the DMT8's internal disk drive and display circuitry if you use low impedance headphones. This is irritating, especially as the interference remains even when the headphones level is turned right down. With headphones of 80Ω or more, the interference is negligible.


Phono connectors are used to connect to the stereo mastering machine with further phonos fitted to handle the direct tape outs, the four direct record inputs, and a stereo buss input. The latter makes it possible to feed another mixer into the DMT8 without using up any valuable channels or aux returns. Having direct access to and from the recorder section is a huge bonus for those who want to work at home but mix in a professional environment, and a further bonus is that the whole shooting match is mains powered, so there are no separate PSUs to worry about.

MIDI In and Out sockets are fitted to facilitate the use of MTC and MMC and there are two optical digital interface ports for connection to a DAT machine. Interestingly, the DMT8's mixer has an analogue‑to‑digital converter at the output, so the digital out port may also be used to pipe your mix directly to DAT. Whether this offers any advantage over the conventional analogue route rather depends on whether or not the DMT8's A/D converters are better than those in your DAT machine.

In Action

In most respects, the Fostex DMT8 is every bit as easy to use as a cassette multitracker, only the fast wind speed is much faster. If you are used to working with computer‑based hard disk audio systems, what the DMT8 offers may seem rather basic, but I prefer to think of it as a conventional multitracker with the bonus of high quality digital sound and cut‑and‑paste editing.

Editing is very simple and reasonably quick — you just have to wait a few seconds while the machine creates a backup file (for undo purposes) and the edit is done. There are no clicks, no gaps and no audible glitches, but I feel the method of marking copy points on‑the‑fly could have been slicker. Providing you are recording conventional pop music, it's easier to work to the internal metronome and execute your edits to bar and beat locations, but classical style material could be trickier.

Turning to the physical feel of the machine, most aspects are very tape‑like — except that the muted ticking noises coming from within the box betray the presence of a hard disk. The auto punch‑in/out and locator functions work pretty much as they do with a regular tape‑based system, but you need to be aware when editing that you can't paste in a new section which starts beyond the point at which you previously finished recording. To achieve this, you need to record an appropriate amount of silence (on any track), which has the effect of moving the song end point further along. Similarly, when you finish recording, it's important to stop the machine as soon as possible, otherwise you are unnecessarily filling up valuable disk space with silence. If you try to do anything illegal, the display usually shows a helpful prompt or warning.

Providing you have enough free disk space, the last edit you make can be undone, which is something tape can't offer.

One trick not described in the manual is recording on the first six tracks and then mixing to the remaining two. Because punching in and out is glitch‑free (courtesy of a 10mS crossfade), you can use this technique to mix a complicated song in sections, and because the mixer has access to the digital output, you can pipe the result directly to a DAT recorder.

The mixer section works conventionally enough and the swept EQ is very flexible. You can get away with plugging a guitar directly into the inputs, though a proper DI preamp will always give better results. Noise was never a serious problem during the test period, though not being able to use capacitor mics (due to the lack of phantom powering) is frustrating — with a digital recorder of this sonic quality, capacitor mics would be an obvious benefit in certain situations. Such noise as is evident undoubtedly emanates mainly from the mic preamp circuits, but this is very small compared to the noise present in most of the source material you are likely to record.


I believe that Fostex have got the DMT8 largely right, but there are a couple of weak areas — notably the lack of expandability and the inability to copy and paste from one track to another. I really can't understand why you can't copy data between different tracks — it would have made compiling vocals easier where you're trying to put together the best parts from three or four different takes. As it stands, any track‑to‑track compiling has to be done via the mixer routing.

In all other respects, the editing system works very smoothly, especially if you work in beats and bars. If you want to slave up a sequencer (the DMT8 acts only as the master), the MTC/MMC protocol allows you to synchronise a sequencer and control its transport functions directly from the DMT8 without using up a track to carry timecode. Unfortunately, it is not possible to use the DMT8 as a slave device, which means it is less suitable for soundtrack use.

The manual is generally adequate, though pretty obviously translated from the Japanese (by the Japanese!?). The technical spec section is very light on detail, telling us only that the frequency response is from 20Hz to 20kHz (but not within what limits), and no noise or crosstalk information is provided at all, despite the fact that there seems to be nothing to hide in this department.

In conclusion, I feel that the DMT8 will appeal mostly to the musician who wants digital sound quality and needs to perform the occasional edit, rather than to someone who wants an overwhelming number of sophisticated editing facilities. Furthermore, the four recorder inputs and eight separate outputs will appeal to music professionals who want to start a project at home, then mix it via a pro desk. Similarly, the direct inputs mean you can patch in external mic amps and such like without going via the onboard mixer. On the down side, as far as I can tell, Fostex aren't yet talking to any of the software sequencer companies with a view to having their hardware supported from within the likes of Cubase Audio or Logic Audio. This is a great opportunity not to be missed, because the DMT8 (at around £1,500) would be a great way to add eight audio tracks with eight separate outs to any MIDI‑plus‑audio sequencer.

Since backing up takes a relatively long time on the DMT8, this kind of system is probably best suited to those who work on one or two songs at a time, rather than those who work on a whole album at once, flitting from one song to the next. Future generations of digital studio may well appear with removable media, which would be rather more practical for those working on large projects, but at the moment there's nothing else like the DMT8 at anything like the price. When you consider that this machine offers a digital 8‑track recorder plus a mixer for such a low price, I don't see how it can fail to be successful.

Time To Back Up

The time taken to back up the data on the DMT8 hard disk equates to four times the length of the song you are working on, so backing up the whole drive will take about 45 minutes. Loading data takes the same time, but if you don't have a DAT machine with an optical interface, you will need to buy the optional Fostex adaptor box.

Editing Facilities

The DMT8 can cope with simple cut, copy, paste and erase editing, but it's as well to check over the definitions of these functions, as not all are as you might expect...

  • ERASE is simply the ability to erase data on one or more tracks, between the locator points you have set.
  • COPY duplicates the data between the location points and transfers it to a clipboard. The manual is rather ambiguous as to whether the clipboard is real or virtual, and I get the impression that data is copied directly from the marked section to its new destination without being stored somewhere as a new file. In other words, the clipboard probably holds just the start and end information for the track to be copied, while the undo file is stored elsewhere on the disk. You can copy one track at a time or copy multiple tracks, and the data may then be pasted into a new location using the Paste command. Setting up the Copy and Paste locations is easy enough but requires at least three button pushes per location point. Start and end points may be captured on‑the‑fly with the Hold button, but you still have to make one pass to grab the start point and a second pass to grab the out point, unless the section you are copying is long enough to let you do both without running out of time. A more practical option would have been to use single button presses after first placing the system into Copy mode. Complexity‑wise, Copy and Paste is about as straightforward as executing an auto punch‑in/out sequence on a conventional cassette multitracker.
  • PASTE places the copied data into a new location. Unlike playlist editing systems, however, this overwrites any existing data at that location. One level of undo is allowed, so this need not be irreversible. However, you should avoid pasting into a location that overlaps the original copied data as this will, in effect, alter the clipboard data. In practice, this means that subsequent paste operations will paste in the altered data rather than that originally selected.

One serious limitation of the DMT8's editing system to my mind is that copied data can only be pasted back into the same track (or tracks, in the case of multiple copies) so you can't take the best bits from three vocal tracks, say, then compile a perfect take on a single track. If you try to paste more data than you have disk space to accommodate it, a warning message will appear in the display. You can get around this by bouncing via the mixer, but this means going back into the analogue domain. Similarly, all conventional bouncing occurs in the analogue domain.

  • CUT: So far the edit commands mean much as you might expect them to, but Cut is the exception. As far as this machine is concerned, Cut means "erase all data beyond the marked point", and like Copy, it can be applied to any number of tracks between one and all eight.
  • UNDO/REDO: Edits can be undone or redone using the Undo and Redo buttons, but these may only be utilised while the recorder is stopped. Only one step can be undone, so if you start recording again or make any other edit, your previous edit will become permanent. Similarly, you can't undo an edit if in the meantime the machine has been switched off.


  • Very easy to use.
  • Excellent sound quality.
  • Direct access to recorder ins/outs.


  • Recording time not expandable.
  • No copying between tracks.


An excellent alternative to the cassette multitracker for the user who doesn't find the maximum recording time of 12.5 minutes too restricting.