Any streetwise business person will tell you that giving the public exactly what it wants, when it wants it, can only work up to a point. You have to hold something up your sleeve as a follow on. For instance, if Yamaha were to put every kind of signal processor you could think of in a single 1U, 19" rack mount case and sell it for under £599, they might well be jeopardising a large chunk of their market of reverbs, DDLs, compressors, noise gates, etc, for some time to come. That doesn't seem to have stopped them, however.

The SPX90 is a pseudo stereo (one in/two out) digital effects unit capable of performing a number of important audio processes with a technical specification quite acceptable for most applications, thus bringing true respectability to the term 'multiprocessor'. It comes with 90 memory locations, the first 30 of which contain preset factory effects (see inset for listing). Each effect has between two and nine editable parameters, and your own personal concoctions can be stored in memory locations 31 to 90.

Ten Types of Effect

Some of the 30 presets are obviously variations on others, and in essence one could say that there are 10 general types of effect on hand: 1 Reverb (including gated and reverse effects), 2 Delay/echo, 3 Modulation (chorusing, phasing, etc), 4 Pitch changing, 5 Sampling, 6 Auto-panning, 7 Vibrato, 8 Equalisation, 9 Compression and 10 Gating. That's a very comprehensive list covering most kinds of popular effect and all with a fairly impressive spec in terms of bandwidth, noise and distortion, which approaches that of the Rev 7. All For under six hundred quid – it's totally amazing.

Used outside of a MIDI system, or without a remote control, programs can only be selected sequentially via a pair of up/down nudge buttons. In practice, this causes no real inconvenience as the longest shuttle time from one effect to another is a little over three seconds. Even so, use of the optional remote would make things much easier. It connects to the SPX via cable and is similar to that for the Rev 7, allowing direct one-button access to programs 1-7 and 31-37, with the remainder being sequentially selectable. As part of a MIDI system, which it will be for most live applications, program changes on another MIDI instrument (1-128) can be made to correspond to the selection of any of the 90 SPX programs desired. Once you've called up the right effect editing is a cinch – simply use the 'Parameter' button to cycle through the variable parameters displayed on the LCD indicator and then nudge their values up and down via a second pair of nudge buttons – mere toddlers' sport. Whilst this sort of centralised digital access control is mind rottingly tedious as found in synthesisers, the comparative simplicity and scarcity of the editable parameters in the SPX90 makes it ideally suited.

As a reverberation system it is flexible and musical, with gated and reverse effects and enough programmability to satisfy most users: reverb time (0.3 to 99secs), predelay (0.1 to 50ms), HF content, HPF and LPF are all adjustable. The quality of the reverb effect is not dissimilar to that of the Rev 7 although it is possibly a little noisier.

If, despite years of faithful IM&RW consumption, a fog of personal confusion continues to hover around the difference between flanging, phasing and chorusing, you will find here a practical demonstration of Yamaha's concept of said differences: two chorusings, two flangings and a phasing – all stereo, all very powerful and effective.

Clever Delay

With effects that involve triggering of some kind, ie gate, compressor, sampling and triggered pan, a 'trig delay' function allows the time relationship of the trigger and the effect to be altered in either direction. With the sampling, for instance, recording can be programmed to commence some prescribed number of milliseconds after the trigger, or conversely, the audio signal to be sampled can be delayed thus ensuring that the leading edge of even the most transient sound is completely captured.

Although, as I've mentioned, the SPX90 is capable of recording simple samples up to half a second long, the Yamaha wordsmiths seem to have gone to some lengths to avoid the use of the word 'sample' in the manual, preferring to substitute the rather ambiguous and modest term, 'freeze'. Perhaps this is the start of a new era of Japanese understatement. Look out for double page colour ads stating, 'The SPX90 – not altogether without its uses'. Sampling Mode A allows the start and finish points to be edited, and in conjunction with the trigger delay facility, this makes for some very accurate samples. 'Auto Trigger' causes the unit to self-trigger on detection of the input signal whilst 'Manual Trigger' leaves the triggering to the operator and a footswitch or front panel button, so that specific sounds can be picked out of continuous programme. Sampling Mode B doesn't permit any such editing, but it is possible to change the pitch of the replay or to control said pitch via a MIDI keyboard. The drawback here is that the sample isn't automatically replayed from its beginning each time it's triggered, it starts from wherever it left off the previous time. Also, on the record side, it's too slow to capture the leading edge of sounds, and thus is limited to rough loops of 'ahs' etc. In both modes overdubbing is possible, so that harmonies or composite sounds can be achieved, and with a 12kHz bandwidth the quality is really quite good.

If the sampler isn't quite as good as a £100,000 Synclavier (!) the pitch change facility is in some ways undoubtedly comparable with the likes of AMS and Eventide. It's incredible what dedicated LSI chips can do for the price. The only possible limitation for studio work is the 12kHz bandwidth, which might not be sufficient to pitch shift complete mixes for the shortening of jingles, etc. But for all other 'adding to' applications it's great.

The delay function is fine though slightly limited by a 500ms maximum delay time, with the repeat echo facility being more seriously cramped by an upper limit of 250ms. Both the gate and compressor effects aren't immediately too impressive suffering firstly from a lack of any kind of metering or trigger indication and also from a positively unorthodox set of controls and parameters that make them difficult to use in the normal way.

Conclusion

For the home recordist and average studio owner alike, the SPX90 is one of the most exciting things to come out of the Frankfurt show. Any criticisms in the text pale into insignificance in consideration of what it can do and also when held in the light of the modest price tag.

For the home studio it has to be the obvious choice as a central processor and I can see professional studios, and thus hire companies, investing in racks of several as an inexpensive way to ensure that the desired effect is always at hand. The unit comes highly recommended to anyone involved in multitrack recording at any level.

RRP: £599