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Multi FX Processor

With multi-fx processors appearing faster than dissenting conservative back-benchers, the pressure is on to come up with something different. Simon Trask investigates a processor that uses analogue circuitry for its unique character.

In an all-digital age, ART's new multi-effects processor opts for a combination of digital and analogue effects. The best of both worlds - or worlds apart?

THE CONCEPT OF combining multiple effects to create a single sonic end result isn't a recent phenomenon. Guitarists have been mixing 'n' matching effects footpedals for years to get their own special sound(s), while the ability to patch in a large number of rack-mounting effects units has long been one factor distinguishing professional recording studios from their amateur brethren.

The advent some three to four years ago of the digital multi-effects processor, in the shape of Yamaha's SPX90, signalled the birth of a new integrated approach to effects processing. While you couldn't use any of its 12 effect types in combination, the SPX90 did provide the impetus for other companies in this direction, and so it was that a few months later Roland's DEP5 took the first, tentative steps by allowing two of its effects to be used together. Subsequent multi-effects processors have upped that number to three or four. So can the multi-effects processor now replace several single-effect processors? Well, it has to be said that limitations in digital processing power typically mean limitations on the configuration, number, flexibility and quality of the effects in multi-effects processors, to the extent that the designation "multi-effects" often signals compromise (or, looked at another way, compromises signals).

Which brings us to US company Applied Research and Technology's new, modestly-labelled SGE Digital SuperEffector/Pitch Transposer With Performance MIDI, which takes the slice of jam sponge with its ability to patch together up to nine effects at once. ART have achieved this by using a combination of digital and digitally-controlled analogue effects, the discrete analogue components taking a not inconsiderable processing load off of the digital processor.

But I suspect this isn't the only reason why the company have opted for a digital/analogue combination. Another consideration is that analogue processing still has the edge over digital for certain effects. Distortion is a case in point, and so it's no surprise to find that distortion and overdrive effects on the SGE come courtesy of analogue processing.

And so we arrive at a leading question: what exactly does SGE stand for? You won't find the answer on the unit, but a picture of a presumably early SGE in an American brochure included with MT's review model reveals the inscription Studio Guitar Effector beneath the previously mystifying initials. Obviously ART subsequently thought better of giving the impression that the SGE was for guitarists only - so maybe they should've renamed it SME for Studio Multi Effector, or even, given their obvious modesty, SSE for Studio Super Effector.

On the other hand, is the SGE really a guitarist's effects unit masquerading as a general-purpose multi-effector (in which case, why is it being reviewed in MT)? String along for a while and you'll find out.


YES, THE SGE is a 1U-high, 19" rack-mounting unit, and ART have done a good job in squeezing so much processing power into such a compact frame. How they've done it I'm not sure, but it should come as no surprise that by today's standards the SGE is quite heavy for its size. Although a heat sink on the unit's rear panel successfully takes the over out of "overheating", if you want to warm your hands on a cold winter's evening then laying them on the left-hand end of its top panel is a good bet.

A 2x16-character backlit LCD window on the SGE's front panel takes care of most of the display requirements, while a three-digit red LED window tells you the number of the current Preset together with what mode you're in (by means of a red dot flashing next to the different digits). To the right of these windows are the aforementioned Preset Up/Down buttons, an effect Bypass on/off button and a button for switching between Keypad and Edit modes, The remaining ten buttons double as a numeric keypad for Preset selection and Edit function buttons, In their latter capacity they become Select Left/Right (for stepping through effect parameters), Value Up/Down, Store, Recall/Enter, Add Effect, Delete Effect, Title Edit and MIDI/Utility.

Two front-panel sliders govern audio input and output signal levels, with input level indicated visually on an LED ladder, while a third, Mix slider balances dry and effected levels when only digital effects are being used and digital and analogue effect levels when both types are being used. The rear panel, meanwhile, contains MIDI In and Out sockets (with a switchable software MIDI merge function allowing incoming MIDI data to be passed on via the MIDI 0ut together with internally-generated MIDI data), a Remote footswitch jack (which can be used to switch effects Bypass on/off or advance through onboard memories) and stereo audio input and output jacks though the majority of the effects processing is mono. For your information, the SGE claims a 20kHz bandwidth and has 16-bit DACs and 20-bit internal processing, while the software version of the review model was v1.03.

"Unlike many other multi - effects processors, the SGE allows you to define your own configurations within the maximum of nine effects per Preset."

On a practical note, the SGE has no power on/off switch and its power cable is fitted with a two-pin plug which can only be connected to and removed from the average power socket with some difficulty neither of which facts endear it to me greatly,

An SGE effect can be stored in any one of 200 RAM program memories which ART confusingly refer to as Presets - a word which generally has overtones of non-programmability. The processor does come with 100 factory-preset effect programs which occupy the first 100 Presets (with number 100 a 'silent' effect), but these memories can be edited and written Into; the preset Presets are also stored in ROM and can be recalled individually into their equivalent RAM Preset memories. Presets can be selected by a variety of means: scrolled through using the Preset Up/Down buttons on the front panel, stepped through using a footswitch connected to the rear panel's Remote socket or selected directly using the front-panel numeric buttons or MIDI patch changes.

Effects can be added to and deleted from a Preset by repeatedly pressing the Add and Delete buttons till you reach the required effect (displayed in the LCD window) and then pressing Recall/Enter. The SGE allows you to choose from a total of 24 effects. The first five are analogue: Harmonic Exciter, Equaliser, Compressor, Distortion and Expander/Gate. A quick spot of arithmetic will tell you that five analogue effects means there are 19 digital effects: these are as follows: Low-Pass filter, Flanger, Chorus, Pitch Transposer, Panner, Mono DDL Short, Mono DDL Long, Reverbs 1, 2 and 3, Gated Reverbs 1, 2 and 3, Tapped DDL Short, Tapped DDL Long, Regenerated DDL Short, Regenerated DDL Long, Stereo DDL Short and Stereo DDL Long.

Unlike many other multi-effects processors, the SGE allows you to define your own configurations within the maximum of nine effects per Preset. Providing you're using no more than four digital effects, then, you can use all five analogue effects together if you want.

The digital effects are a different box of tricks, however. Most notably, if you select pitch-shifting (an effect which is notorious for its heavy-duty requirements on processing power) then the only other digital effects made available to you are Low-Pass Filter, Mono DDL Short and Mono DDL Long - reverb, for instance, goes straight out of the (LCD) window. If you select Reverb or Gated Reverb 3 then only the Low-Pass Filter and Mono DDL Short digital effects can be used as well. Selecting one of the reverb or DDL effects in each case cancels out the other effects of the same type, while selecting flanging, for instance, leaves you with a choice of Low-Pass Filter, Mono and Stereo DDL5 (Long and Short), and Reverb and Gated Reverb 1 and 2 - and from these you could select Low-Pass Filter, one reverb and one DDL.

If you haven't already realised, I should also point out that we're talking serial rather than parallel effects processing on the SGE - you can't put one instrument through one effect and another through a completely different effect at the same time. Furthermore, with a few exceptions the order of the effects is determined by the SGE, not by you. One consequence of the SGE's mix of analogue and digital effects is that the two types can't be mixed up -the analogue effects come first, because their output has to be digitised by the digital processor for effects processing in the digital domain. However, you can, for instance, position the Harmonic Exciter and the Equaliser before the Compressor or after the Distortion, while the Flanger can run in parallel with Reverb or Delay effects or be placed at the end of the effect chain (running an overdriven guitar through a long reverb decay which is being flanged is great for atmospheric droning sounds - I just wish the SGE would've allowed me to use auto-panning as well!).


THE JEWEL IN the SGE's crown is undoubtedly its analogue Distortion processing, which breathes in a way that digitally-created distortion just doesn't, and avoids that typically digital harshness. You can choose one of 12 distortion types, with three types each of overdrive, distortion, turbo overdrive and turbo distortion. On top of this you can program drive (which sets the amount of distortion), bite on/off (bite, as the name suggests, provides a more cutting attack) and level. The range as well as the quality of the SGE's distortion effects is impressive, from a sweetly singing sustain to a full-frontal distortion attack. It's been a while since I played guitar, but once I'd plugged into the SGE I didn't want to stop; it made me want to play, guv'nor, which I guess is the sign of a good effect.

The Harmonic Exciter, Compressor and Expander/Gate are all useful inclusions on the SGE which perform their allotted functions well. The EQ section is basic, with three bands centred at 100Hz, 1kHz and 1OkHz, all with 12dB cut and boost. It's useful as far as it goes (particularly when it's placed after the distortion, where it can add further warmth or harshness as required), but certainly not thorough-going enough to cater for every requirement.

"The quality of the delayed signal preserves the clarity of the original signal right through to the final delay, even with heavy regeneration."

The strategically-positioned digital Low-Pass FiIter, which operates on the output from the analogue effects, is the simplest effect on the SGE: you merely select a cutoff point anywhere from 665Hz to 15kHz. The Flanger and Chorus effects, which have a slightly metallic edge as opposed to warmth and richness, have width, speed and regeneration and width, speed and delay (up to 66 milliseconds) parameters respectively.

The Pitch Transposer functions reasonably well, with coarse tuning (a maximum of +/- one octave in semitone steps) and fine tuning (up to +/- one semitone in a mixture of six- and seven-cent steps) allowing for harmonisation and "thickening" effects. You can choose between three response rates for the shifted signal: smooth, normal or quick. What you lose in pitch exactitude (particularly with chords) you make up for in quick response time, and vice versa. In addition to setting the level of the shifted signal you can set a regeneration amount which governs how many times the shifted signal will carry on shifting at the specified interval, the delay amount being governed by the response rate setting. If you patch Mono DDL Short or Mono DDL Long in before the Pitch Transposer you can create more complex rising or falling cascade effects. For further weirdness, defining a "root" MIDI note number results in the specified pitch-shift interval changing with each different note you play on your MIDI instrument.

Panning turns out to be purely of the auto variety, and provides the absolute minimum you could want from a panner: modulation amount (0.100%) and speed (0-15).

In contrast, the prize for most thoroughly implemented effect must go to DDL, which ranges from a single Mono delay (0-100 and 0-240 milliseconds for Short and Long options) through Tapped and Regen options to Stereo (separate delay times for Left and Right channels plus regeneration, high-frequency damping and level settings - with delay times ranging from 0-360 and 0-500 milliseconds for Short and Long options respectively). Longer delay times wouldn't have gone amiss, but there's no arguing with the quality of the delayed signal, which preserves the clarity of the original signal right through to the final delay, even with heavy regeneration. I'm sure the DDL aspect of the SGE will see much use.

Last but not least, there's the reverb, or Reverbs 1-3 and Gated Reverbs 1-3. Reverb 1 allows you to select Hall, Room, Plate or Vocal, Reverb 2 adds a second set of these four types, and Reverb 3 adds a third set (allowing you to choose one of 12 reverb types). All three Reverbs allow you to program a decay time of from 0-25 seconds, a high-frequency damping value, level (dry/reverb balance) and a position within the location (from front to rear in 17% steps), while Reverb 3 adds a Diffusion parameter. Gated Reverbs 1-3 allow you to select one of Slope, Flat, Reverse A and Reverse B reverb types (with each Gated Reverb having its own variations), together with diffusion, level and decay time (0.05-0.25 seconds for Gated Reverb 1, 0.05-0.40 seconds for Gated Reverbs 2 and 3).

I found the overall reverb quality a bit disappointing: on the thin side, with a slight ring to it (even when the damping is brought into play) and a tendency to "warble". Adequate, particularly when used in conjunction with several other effects, and not lacking in presence, but it wouldn't be my ideal choice of reverb.


MIDI ON THE SGE has several uses. Firstly it can be used to call up onboard Presets from a sequencer or keyboard via MIDI patch changes. You can set the SGE to respond in Omni mode (on all MIDI channels) or on an individual channel (1-16). A MIDI Program Table can be created in which each MIDI patch number can be set to call up any one SGE Preset, a useful feature which originated on MIDI'd effects processors - and a necessary one in the SGE's case, as it has more Presets than there are MIDI patch numbers. Individual Preset, all Preset and MIDI Program Table data can be transmitted via MIDI SysEx, which means you can store it to generic patch librarian software as a file or to a MIDI sequencer as part of a song for which the effects are intended.

But perhaps the most interesting use for MIDI on the SGE is that of real-time control of effect parameters. ART have logically enough called this "Performance MIDI", and they've come up with a fairly extensive implementation. You can define up to eight incoming MIDI controllers for each Preset, and assign each of these controllers to one of the parameters of that Preset's selected effects. The MIDI controllers can be any one of MIDI controller codes 0-120, note-on key number, note-on velocity, note-off key number, note-off velocity, pitchbend wheel, polyphonic aftertouch or channel aftertouch - a pretty comprehensive choice.

"Perhaps the most interesting use for MIDI on the SGE is that of real-time control of effect parameters - ART have called this Performance MIDI"

In addition, you can program the polarity of the SGE's response to each controller (whether maximum Incoming MIDI value will generate the maximum effect parameter value or vice versa) together with the value range over which each parameter will respond (so that a MIDI controller can generate a modest or an extreme response as required particularly useful in the case of footswitch controllers). The best means of defining the value range would be to set minimum and maximum values, but unfortunately the SGE doesn't make life that easy: you have to set a central value together with a scale number which defines in no readily apparent way how much the response can vary each side of this value.

However, there's no denying that the extent and the flexibility of MIDI control on the SGE is impressive. Any examples can only scrape the surface of what Performance MIDI can do, but here goes: MIDI velocity controls high-frequency damping on the reverb, with higher velocities reducing the damping for a brighter reverb sound (this would require reverse polarity response); the same response can be generated from MIDI note numbers so that low notes use maximum damping and high notes minimum damping; MIDI notes defined for two of the eight possible controllers control the low and high EQ bands simultaneously, so that low notes have a bass boost and high notes a treble boost; the sustain pedal controls reverb decay time (which could switch from off to maximum); another MIDI footpedal controller switches distortion bite in and out; the pitchbend wheel controls DDL regeneration, with higher bend values creating longer regeneration...

Well, you no doubt get the idea by now. Of course the flexibility of Performance MIDI is rather like the sonic potential of synths: theoretically you may be able to create an infinite number of sounds on a synth, but how many of them are musically useful to you?

What you make of Performance MIDI is really down to your own imagination, which isn't to say that Performance MIDI will allow you to achieve everything you can imagine. One thing I often found was that I wanted what the SGE can't manage: several different values for a parameter going at the same time, so that for instance you could have different pan rates or different DDL rates for different concurrent notes. Another point worth making is that, because you have access to so many different parameters you may find that some of the digital effects parameters don't respond well to rapid and extreme changes in value (sometimes there are faint clicks, presumably as the processor tries to keep up with the real-time adjustments).


THE SGE ISN'T only suitable for guitarists, but because of its excellent distortion processing I'd particularly recommend guitarists to check it out and that means commercial recording studios should, too. Digitally-created distortion, which all too often sounds harsh and grating, just doesn't - to these ears, anyway - match up to the warmth, depth and variety of the SGE's analogue-generated distortion.

Overall the SGE's sound quality is an appealing mixture of clarity, brightness and warmth, though the balance does depend on what combination of effects you're using. The DDL effects are impressive, while the reverb is adequate but wouldn't make the SGE my first choice of reverb unit.

Programming the effects is a straightforward business, both functionally and conceptually, even if all the button-pushing as you step through the effects list and the parameter displays can get a little tedious. For those of you interested in real-time MIDI control of effects parameters, the SGE offers all the control sophistication you could wish for - again, made available in a readily understandable way.

The multi-effects processor market is pretty crowded at the moment, and each processor seems to have its own effects priorities and its own way of going about things. The SGE (which price-wise sits somewhere around the middle of the market) is distinguished by the number of effects it provides, the number which you can use together, its combination of analogue and digital effects which lends it an attractive and individual sonic character, its distortion processing and its sophisticated Performance MIDI implementation. All of which means it deserves some serious consideration.

Price £629 including VAT.

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Keynote Chameleon

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FM Melody Maker

Music Technology - Copyright: Music Maker Publications (UK), Future Publishing.


Music Technology - Dec 1989

Gear in this article:

Studio FX > ART > SGE

Gear Tags:

Digital FX

Review by Simon Trask

Previous article in this issue:

> Keynote Chameleon

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> FM Melody Maker

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