Fostex 250 Multitracker
Freelance recording engineer Dave Lockwood waives his normal duties to bring a hands-on report of this highly popular cassette-based multitracker, designed to highlight techniques he's found useful during his own recordings.
The Fostex 250 was launched almost two years after Teac/Tascam pioneered the four-track cassette/mixer concept with their innovative M144 'Portastudio'. Benefiting undoubtedly from its later entry into the market, the 250 improved on its forerunner in a number of ways and rapidly established a reputation for being particularly simple to operate, in addition to having a superior audio performance.
Standard cassettes are used, but at double speed (3¾ips), and whilst the actual track width of the tape is only the same as an ordinary stereo cassette recorder, where two tracks are used in each direction, the Fostex uses all four in the same direction, the doubled speed giving improved high frequency response and dynamic range. Dolby C noise reduction is used and must take some of the credit for the 'clean' quality of the HF (high frequency) response of the 250. The system seems particularly well suited to this format where quite a large degree of noise reduction is required (Dolby C offers 10dB more noise reduction than the widely used Dolby B circuit, and theoretically 10dB less than the 30dB provided by the dbx system), combined with the minimum of unwanted side-effects.
One of the major attractions of the Fostex was the ability to record on all four tracks simultaneously and it still remains the machine which offers the greatest flexibility in terms of the number and combination of tracks to be recorded.
The neat, logical layout of the Fostex assists the inexperienced user by making clear distinction between the mixer and the recorder functions; the signal routing can always be traced easily and so the principles of operation are quickly picked up, without the need for too frequent reference to the instructive Owner's Manual. The simplicity of use has, however, in no way been achieved at the expense of any versatility, and the more familiar you become with the unit, the greater the possibilities seem.
The mixer section has four identical input channels, with the input connectors, ¼" jack sockets, located on the front face of the unit. This is a distinct improvement over having the inputs on the rear panel, but having used this machine for some time, I think that I would willingly sacrifice a little in the way of neatness in order to have all the connections made at the front.
The rear connector panel is certainly comprehensive enough to be used as a sort of mini patchbay, but if you are working in a confined space, as many home recordists will be, then anything but the most basic of sessions will inevitably involve much physical leaning over the top of the unit, trying to remember what the layout of the sockets is when viewed upside-down. While on the subject of connectors, I must question the practical necessity for the use of recessed jack sockets on the inputs. Many home recordists have to press into service every lead they can lay their hands on, and it is inevitable that sooner or later you will complete some complicated external hook-up and arrive back at an input socket with an angled jack plug! Somehow the irritation that this causes is out of all proportion to the few seconds that it takes to swap the leads around.
The input channel is arranged the opposite way up to the traditional layout of most mixers, as the input selector and gain control are located just above the fader, and in some ways this is a more logical arrangement. The fader tops have a pleasant, low-profile design with a ribbed, concave surface which is more than just a purely cosmetic feature, as a wide, concave-topped fader is significantly easier to operate accurately with one finger, which is why the shape is so widely used.
The sensitivity and impedance of the Mic/Line inputs has been chosen to accommodate the widest possible variety of sources, with the minimum of interfacing problems. The sensitivity is continuously variable over a more than adequate 50dB range, and it is perfectly feasible to plug in a guitar or bass directly, without the need for a DI box.
The front panel input is active only when the channel's 'Line/Mic-Off-Tape' input selector switch is at the Line/Mic position. When selected to Tape, the input channel is fed with its corresponding tape track on the recorder for mixdown or for bouncing tracks together. The Off position is also actually quite useful as it gives an instant channel mute facility, without needing to alter any other settings.
The Fostex features two-band, fixed frequency EQ, of a slightly unconventional nature. The two controls have centre detents in the nominal 'flat' position and provide 12dB of signal cut or boost at 300Hz with a shelving action, and a similar range of control, centred on 4kHz, with a peaking action. This unusual EQ is perhaps the most criticised aspect of the Model 250 as it provides no conventional Bass and Treble controls, but only effectively an upper and lower Mid control.
This requires the user to think rather differently about the use of the EQ section as it is simply not possible to do some of the things that you would do with conventional controls. For example, you can't remove just a little unwanted 'boominess' from a bass instrument, because cutting at 300Hz (and with the shelving action, everything below 300Hz disappears as well) takes away such a lot of the rest of the sound that you do want, at the same time. This means that you must always try to get the sound at source, as close as possible to what you want, and then only use the EQ for enhancement. This is, of course, very sensible recording practice under any circumstances, but it can often make harder work of the job as well.
I feel that the most unfortunate limitation of this EQ lies in its complete unsuitability to compensate for the 'generation loss' that occurs when tracks have to be re-recorded through the process of track bouncing.
With analogue systems such copying losses are inevitable and there is a natural tendency to attempt to make up for some of the treble loss by boosting the upper equaliser control. Unfortunately, the action of this control does not have any effect on the upper frequencies where the copying losses actually occur, but merely introduces a lift in the presence region. However, as the equalised sound certainly appears to be superficially brighter, the 4 kHz control inevitably gets used for this purpose. By the time you have bounced a few tracks together and then done a final mixdown, the resulting stereo master can have such a large 'spike' in the response, from repeated boosting at 4kHz, that it can be quite unpleasant to listen to. Obviously this is not what the designer intended and arises only through misunderstanding of what this EQ can and can't do.
A better solution to 'generation loss' on the Fostex seems to be some judicious cutting at 300Hz; the gentle reduction in bass and lower middle frequencies giving the impression of more top-end, while maintaining a smoother overall response, without the unpleasant effect of excessive narrow bandwidth boost in the presence region. I would suggest that a 'treble' control, fixed at a higher frequency and with a shelving action, would be more useful. Whilst the concept behind this EQ section is not without some merit, it must be questionable whether it is really best suited to the needs of the user of this type of unit.
Signal routing on the Fostex is achieved by selecting either of the two pairs of busses 1 and 2, or 3 and 4, using the '4 Chan Buss' switch, which also has a central Off position. Once a pair of busses has been selected, the routing is then completed by the operation of the Pan control, panning fully left for the odd-numbered track, and right for the even-numbered one of the pair. The signal can be panned into any position across both of the tracks if necessary, but for the more usual arrangement of one channel assigned to one track, it is important to set the Pan control fully over to the appropriate side to avoid losing some level.
It is possible as an alternative, however, to bypass the channel assignment switch altogether and use a patch cord to connect from the channel's Direct Out socket, directly to the Record In socket of the track you want to record on. With the buss selector switch in its central Off position, the Direct Out-Record In link becomes the ideal point to patch in an external processing device like a compressor or noise gate, but some interesting results can be achieved by using the patch point with an effect like a flanger or chorus, but also utilising the assignment switch routed to the same track. This provides a direct path carrying 'clean' signal in addition to the processed signal from the external device, and many effects can be made more subtle and interesting in this way. This technique can in fact be particularly helpful when using effects with drum machines as some of the more extreme settings can be used to create interesting sounds, while the power of the basic sound is still retained by the presence of the direct, 'clean' signal.
Although you must always be careful not to patch a channel's output back into its own input, it can often be useful to take a feed from a Direct Out socket, through an effect or processor, and then return into the Mic/Line input of another channel. The signal is then able to be equalised again, after processing, before being routed to a tape track in the normal way, with the buss switching and Pan pot. Whenever parallel signal paths are combined onto the same track, in the same way that I have suggested, the levels are additive so it may sometimes be necessary to reduce the gain setting to avoid overload.
Many Fostex owners initially have to make use of guitar pedals for effects, and some good results can be obtained in this way, although they can sometimes be rather noisy. The noise performance can often be improved by using the effect at line level, fed from the channel Direct Out or from the auxiliary send, rather than patching it between the instrument and the input. Some pedals, however, simply can't handle signals at this level and serious distortion usually results, but the condition of the battery is often critical in this respect, so before discarding a pedal as unsuitable to be used in this way, try a fresh battery or even better, an AC adaptor.
Each channel has a post-fade, post-EQ auxiliary send, which can be used in conjunction with the auxiliary return inputs, to control echo or reverb on mix-down. It could also provide a sub-mix to an effects device when track bouncing, with a spare input channel perhaps used for the effect return, although you must be careful not to turn up the Aux send on the channel used as the 'return', as this would create a 'loop' and cause oscillation/feedback.
A 'Monmix' control completes each input channel, and these are used to monitor the four tracks of the recorder. This is the best signal to listen to when recording and overdubbing as it most accurately lets you know what is going onto tape and what has already been recorded. The 'Monmix' signal derived from each tape track (or recording input signal if the track is in Record) is combined into an independent, mono monitor mix, which can either be taken out to an external monitoring amp and speakers, or monitored via the unit's own headphone outputs.
The operation of the Monmix control of a track that is to be recorded is governed by the status of the Record switching, and this can be the source of some confusion at first. In order to hear the input signal via the Monmix pot, it is necessary to press the Record Track switch for the appropriate track, and then press the master Record button, located among the tape transport controls. A red LED above both switches will flash to confirm 'Record Ready' mode, and you are then able to hear the signal that you want to record with its monitoring level (not its recording level) controlled by the Monmix pot.
Having set up the sound that you want to use, you may then wish to rehearse along with the tape, so you hit the Play button, whereupon your input signal disappears from the monitoring! In order to get it back, it is necessary to press the master Record button again, after the tape is moving (if you hit Record and Play together you will enter Record, which is probably not what you want if you are just rehearsing a part).
If this seems rather unnecessarily complicated, there are actually very good reasons behind the procedure; one is that it virtually eliminates the possibility of thinking that you are recording when in fact you are not, and the other involves the monitor switching required when 'dropping-in'. To make a successful drop-in you usually need to hear the material already recorded on that track of the tape, up until the exact moment that you drop-in (enter Record with the tape running), you then need to instantly change over to listening to the input signal that is being recorded instead. This monitor switching is accomplished automatically, and once the procedure is understood, its importance becomes immediately apparent.
The technique of 'dropping-in' (or 'punching-in') has become an essential part of multitrack recording, both for fixing mistakes and for track-sharing (recording of several instruments which never appear simultaneously in the piece, on the same track, to make the most efficient use of the tracks available).
There are three ways, each with its own particular use, of making a drop-in on the Fostex 250, including the use of a remote footswitch (Fostex 8050); obviously for the musician working alone this is a great asset as it is possible to have both hands on an instrument and still be able to make a tight drop-in.
To achieve this, the track to be recorded is pre-selected to 'Record Ready' with its Record Track switch, then once the tape is in motion, operating the footswitch will enter Record; pressing the switch again will cause the machine to drop-out of Record.
If you have no need to use a footswitch, the same procedure can be accomplished using the master Record switch instead ('Play' must also be depressed at the same time); entry into Record from Record Ready being visually confirmed by the flashing LEDs remaining steadily illuminated. To exit from the Record mode it is necessary to stop the tape (or use one of the functions whose logic must go through Stop), and this can sometimes rather tend to break up the 'feel' of the track for the musician, when a number of drop-ins are to be made.
To overcome this it is possible to use the third drop-in method, where the machine is entered into Record mode with none of the Record Track switches depressed. Subsequently, pressing any of these switches will enter that track into Record, but with the additional facility of being able to drop-out of Record just by pressing the switch again, without the tape having to stop.
The Fostex can drop-in very quickly, but like many other machines it doesn't drop-out again quite as fast due to the gap between the Erase and Record/Play heads. But with practice you can soon learn how much space you need to exit from a drop-in without 'clipping' the following material. The drop-in facility is also quiet (some systems have been known to put clicks onto tape) and provided that you don't try to do the impossible, like punching into the middle of a sustained note, it can give excellent results.
The Fostex has a stereo auxiliary return circuit with its own level control, designated 'RCV 1-2'. This is useful as a stereo reverb/echo return facility on mixdown, but the inputs can also be used for recording from any line level source, such as a stereo tape recorder. When using an echo or reverb with a single mono output, it can be advisable to split the signal into both auxiliary return sockets, otherwise the effect will appear only on one side of the mix, which can sound a bit odd. A further use for the RCV 1-2 inputs is to interface with another mixer, to make available a larger number of input channels. The RCV 1-2 control should be set to number '7' to optimise headroom and noise, and the controls on the external mixer then used to set the required level; using the RCV 1-2 circuit in this way has the advantage of leaving all the Fostex input channels still available for further input signals.
The headphone monitoring is governed by a rotary control, located just above the Master Fader. Its centre detented position is Off, but rotating to either side gives a choice of headphone monitoring signals. Moving the control to the left allows the monitor mix (Monmix) to be heard in mono in the headphones, while moving to the right monitors the output of the four busses, with 1 and 3 assigned to the left, and busses 2 and 4 sent to the right. This is useful for stereo mix-down or when bouncing down tracks into stereo, but if it is used for general monitoring you can occasionally encounter a totally one-sided headphone mix, which can be rather disorientating. I feel that the internal headphone amplifier should certainly have been made more powerful as it tends to 'crack up' even at fairly modest levels when high impedance, 'open' design headphones are used.
The Fostex features four large illuminated VU meters, supplemented by 'peak' LEDs. The meters have standard VU ballistics, but the LEDs are much faster and are able to indicate instantaneous peak levels approaching the point at which clipping will occur. In combination, the meter and the LED give a very effective indication of the optimum recording level on all types of signal.
Full 'logic' transport controls are provided, including a very useful 'return to zero' function which, if the LED tape counter is reset at the beginning of a 'take', enables you to repeatedly rewind almost exactly to the start, without any annoyingly time-consuming shuttling backwards and forwards. This 'Zero Rtn' function is an essential facility in a machine of this type, but I am sure that many users would find it even more useful if it had been extended to offer a 'return to zero and play' function as well (activated perhaps by pressing the Play button whilst holding down Zero Rtn). Many domestic stereo cassette machines now have this facility and I am sure that its inclusion here would certainly have been appreciated.
A Pitch Control is provided, offering a plus and minus 10% variation in tape speed; this has many uses such as 'tuning' the tape to an out-of-tune piano, or adding a little extra excitement to a track by speeding it up on mixdown, or even playing 'impossible' solos by slowing the tape down for overdubbing! The control has a centre detent to indicate normal speed, but this can be rather easily overlooked and perhaps there should be a warning LED to indicate 'vari-speed operation'.
High bias 'Type II' cassettes are specified, such as TDK-SA or Maxell UD XL-II, and there seems to be no benefit to be gained from using a more recent formulation such as TDK-SA X. It is recommended that tapes no longer than C90s are used, for although running time on the Fostex is only a quarter of the total cassette time (22½ minutes from a C90), longer cassettes like C120s actually use thinner tape which could be prone to stretching or breakage when subjected to the particular strains of multitrack use.
Perhaps the single most useful thing the Fostex owner can do to ensure the continued quality of the machine's performance, is regular and thorough cleaning of the heads and tape path with a proprietary head cleaning fluid, or pure isopropyl alcohol (available from chemists). With any tape, some degree of oxide shedding from the tape is inevitable, but regular maintenance can prevent this from causing any problems.
Demagnetizing (sometimes called degaussing) should also be performed at regular intervals, to neutralize the buildup of residual magnetism in the tape path. A demagnetizer can seem a rather hazardous device to the inexperienced user, but the comprehensive and informative Owner's Manual contains a helpful step-by-step guide, which should ensure that the procedure is accomplished safely.
The Fostex 250 has managed to successfully reconcile the desire to be simple to understand and easy to operate, with the need to be versatile and to offer as many operational options and facilities as possible. Apart from the few reservations that I have expressed, and the rather more serious deficiency of the EQ, the unit achieves all that could be expected of it. The audio performance, assisted by the Dolby C circuitry, is exemplary for the four-track cassette format, and the high quality of the internal construction and layout inspires confidence in both reliability and serviceability. I feel that the Fostex 250 has achieved its fine reputation on merit, and that it continues to set the standard for its competitors.
The retail selling price of the 250 Multitracker is £661 inc VAT.
If you experience difficulty in locating one, contact UK distributors Bandive, (Contact Details).
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User Report by Dave Lockwood
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