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Roland SDX330

Stereo chorus with that 3-D feeling

Can RSS technology add a new dimension to the stereo chorus unit we all know and (sort of) love? Nigel Lord plugs in the Roland SDX330 and is favourably impressed

Not Just another chorus unit - the SDX330 deserves its elaborate 'Dimensional Expander' label

Without ever quite being the name to have emblazoned across your effects rack, Roland have nevertheless cultivated an enviable record for producing innovative, cost-effective designs dating back to the now much sought-after Space Echo models of the late 1970s.

Thinking about it, there never has been a time in the past 15 years when I haven't had a Roland processor somewhere in my setup, though the only reason I regret parting with my original RE501 is the price it might have now commanded had I not sold it to buy my first digital machine. How anyone's nostalgia for these tape-devouring relics should lead them to pay such inflated prices is beyond me. Analogue synths are one thing, tape echo units are quite another. But I digress...

One of Roland's major developments in processing technology over the past few years has been their RSS system, which first appeared in commercial form back in 1991. Research involved dummy head experiments to re-create the binaural processing our ears do for us naturally. It's rather complex, as you might imagine, and required detailed analysis of sound paths and reflections in order to develop a system capable of producing an aural image that goes over the listener's head and under his feet.

A significant problem was the crosstalk produced when listening through conventional speakers; this called for a special processor to generate signals for the left and right channels to compensate for the effects of the other.

The resultant machine, when it emerged, was seized upon enthusiastically by top artists and studios, but proved way out of reach for the hoi polloi. Thankfully, Roland have always been adept at repackaging technology within a range of products in order to maximise the return on their R&D and keep prices to a minimum.

The result is that RSS has already been included in a couple of affordable processors - the SRV330 Dimensional Space Reverb and the SDE330 Dimensional Space Delay - and now makes a further appearance within the most recent member of that family, the SDX330 Dimensional Expander.

Whether or not Roland designed the new machine to complement these other units isn't entirely clear. Certainly, there's a degree of overlap with the SDE330 in the form of flanging and chorus programs which both models provide. But, for the most part, the SDX ploughs its own furrow with an intriguing selection of stereo imaging and sonic-enhancement programs made possible through a series of specially-programmed algorithms - and, of course, RSS.

"The flanging programs sky-ride across the mix... yet are subtle and usable"


Programming opportunities for the user are many and varied, and can make the SDX seem a little daunting as you wander out of the familiar territory of delay time, feedback level, and room size and run head on into altogether more exotic parameters such as elevation, azimuth, and ambience cutoff frequency. It's easy to feel a little out of your depth at times. But there's no gain without a certain amount of pain and understanding any new technology always requires a little effort.

Anyone already familiar with Roland's SRV330 or SDE330 will have something of a head start here - at least as far as the user interface is concerned. The SDX shares the same front-panel layout as its brethren, and also identical parameter access within the 'scrolling page' system designed to cut down on the button-pushing and go some way to overcoming the limitations of the two-line display. The system comes into operation when Page is selected along with Edit from the front-panel buttons; instead of altering individual parameter values, the rotary data control or increment/decrement buttons are used to scroll through the many parameter options associated with each program.

The three parameters displayed at any one time may be accessed by pressing one of the three Function buttons to which they are assigned (according to their position in the display). This automatically switches the SDX back into parameter edit mode and allows adjustment via the data entry knob or the increment/decrement buttons in the normal way.

Other front-panel buttons are used to store edited programs (Memory), access the various global parameters (System), and leave the current edit mode (Exit). Additionally, there's a Bypass switch and a 'Program' button used to select the type of information shown in the display; in one setting this reveals the effects parameters along with the program name, in the other, the algorithm number and type are included with the program name. This is designed to make it possible to distinguish between two programs sharing the same name but using different settings. Over on the left of the unit you'll find the dual (ganged) input level and single output level controls together with the input LED ladders which reach red when clipping takes place.

Rear-panel hardware comprises two pairs of quarter-inch jacks for stereo in and out (mono on left-hand sockets), -20/+4dB attenuation switches for both input and output, plus standard MIDI In, Out, and Thru ports. A selection of footpedal sockets provide the connection point for a bypass footswitch (duplicating the action of the front-panel switch), a control footswitch (providing switch control of various assignable parameters), and an expression pedal (offering continuous real-time control of assignable parameters).

MIDI, stereo ins and outs, and footswitch connections line the rear panel

"The SDX could earn its keep as an audio tool, not just another effects processor"


Following the precedent set by the SDE330 delay, the SDX offers 300 program locations - 100 preset and 200 user-programmed. This is in contrast to the SRV330 which provides a far more sensible 400 program slots - 100 user and 300 preset. I say more sensible not because of the extra program memory in the Space Reverb, but because the proportion of presets to user-programmed effects - 3 to 1 - is just about right. Frankly, life's too damn short to spend it programming complex effect chains. What's needed are plenty of presets to sift through, then maybe 100 or so user locations to store any customised versions.

As with all modern effects units, the processing chain is built around a series of algorithms in which the basic component effects are arranged as a kind of flowchart. Given that most manufacturers are now pretty adept at building chorus generators, delay devices, EQ stages and so on, it is usually here, in the programming of the algorithms, that the success or failure of the processor can be gauged.

So what of the SDX? Well, some 16 different algorithms are included (you'll find them listed in the panel) covering chorus, panning, flanging, ensemble and rotary effects - and a fascinating bunch they are, too. Chorus algorithms predominate among the preset programs, but are often quite different in character to the kind of chorus effects you might be familiar with. This is due in no small part to the use of individual low, middle and high-band LFOs, complex equalisation and cross mixing - and our old friend RSS.

Many of the algorithms provide effects which, while often dramatic and capable of lifting an instrument's profile, resist easy categorisation as being this kind of effect or that. The exceptions to this are the flanging programs which sky-ride across the mix in the way that flanging programs do - yet even these seem somehow more subtle and a lot more usable than is often the case.

Talking about mixes brings me to an interesting point. After connecting the SDX to my mixing desk in the conventional way, via a send and return loop, I then decided to reconnect it using the insert points across the stereo outputs so that the entire mix was being processed. I had assumed that only the panning and RSS effects would be useful in this kind of setup, but the subtlety and sophistication of many of the other programs made it possible to use them, too. In fact, a couple of rather lifeless mixes of a track I've had lying around the studio for some time were completely revitalised doing just this.

I particularly liked 'Vintage CE2' [named after a classic Boss chorus pedal - Ed] for its uncanny ability to turn the most simple bass and drum track into an instant dub/reggae groove, and 'Sizzle On Top' for its great back-of-the-hall live feel. 'E Piano Ensemble' has a dark, mysterious quality to it and 'Lifted Chorus' really does, er... lift.

Quite a number of programs on the SDX could be used to 'widen out' mixes recorded in mono - or near mono. This might prove useful when working with mono samples or importing sound files in a direct-to-disk recording setup, and points to the SDX earning its keep as an audio tool in the studio, rather than as simply another effects processor.

The SDX330 shares its front-panel layout with the SRV reverb and SDE delay, including the 'scrolling page' edit display


My only real criticism of the SDX330 is one that I would apply to most processors that provide the icing on the cake such as this. Simply put: the cake often tastes good enough on its own.

It could be argued (and often is by engineers and producers) that this kind of processing is just gilding the lily. Not only that, but sonic enhancement of whatever type is something you can become very dependent on, to the point where switching it off becomes unthinkable - until this happens accidentally and you don't notice for half an hour.

That said, the programs offered by the SDX are far too attractive to be ranked alongside simple sonic enhancers and make their presence felt in a much more demanding way. And this, I feel, is the solution to how they should be used - right upfront, processing the entire mix if necessary.

The obvious example of this would be a track like Hendrix's 'Voodoo Chile (Slight Return)' where the application of flanging (or was it phasing? No-one seems sure) was a bold statement and quite integral to the song itself: the guitar desperately holds on as the processing drags it into near extinction, then surges forward as it cycles round and over the rest of the mix. Exciting stuff, and certainly the kind of avenue you could explore with the SDX in your weaponry.

Given the publicity surrounding (sorry!) the RSS system, it comes as a surprise to learn that it is only included in two of the algorithms and 11 of the presets. You are, of course, free to program more of your own effects featuring RSS, but as with the earlier SDE330 and SRV330, the extra 'dimension' added by Roland's imaging system is not as dramatic as you might expect, and certainly no substitute for the full RSS programming options offered by the complete (and costly) professional product.

But, with the help of RSS and a great deal of thoughtful programming, Roland have genuinely taken the concept of 'digital chorus' a stage further with the SDX330. Don't take my word for it, though. Listen to this month's CD and hear for yourself.

The essentials...

Price: £699 inc VAT

More from: Roland UK, (Contact Details)


1 Stereo Chorus
2 Stereo 3D Chorus (RSS)
3 3D Panner (RSS)
4 Space Chorus
5 2 Band Chorus
6 3 Band Chorus
7 4 Band Chorus
8 Stereo 8 Phase Chorus
9 16 Phase Chorus
10 Detune Chorus
11 Ensemble
12 Wave Chorus
13 Vintage Chorus
14 Stereo Flanger
15 Rotary
16 Ambience Chorus

On the RE:MIX CD

Hear what the Roland SDX330 can do on this month's Re:Mix CD. The programs demonstrated are as follows:

- 4 Lifted Chorus
- 5 Vintage CE2
- 6 E.Piano Ensemble
- 7 Like Buttah!
- 8 Sizzle On Top
- 9 Slow Spinner.

All program material for this demo was taken from Ninja Tune's (excellent) DJ Food - Jazz Breaks collection, produced by Coldcut. Volumes 1-4 are currently available. For more info contact: Ninja Tune, (Contact Details)

Effects & parameters

1 3D Effects (RSS-generated effects that allow you to adjust the position of the sonic image left or right, up or down relative to the listener)
Azimuth (moves the sound horizontally along the perimeter of an imaginary sphere. Adjustment is within a range of approximately 180° to the left or right).
Elevation (moves the sound vertically along the perimeter of an imaginary sphere. Adjustment is within a range of approximately 60 degrees up or down).

2 3D (RSS) Panner (uses RSS effects to create the illusion of sound revolving around the listener)
Start Position

3 Chorus
LFO Phase
Cross Mix
Pan Mix
Chorus Filter
Chorus Level
Crossover Frequency
LFO Waveform
Cutoff Frequency
Mode (for the 16 Phase Chorus algorithm)
Ambience Level
Pitch (for the Pitch Shifter)
Ambience Filter (selects the type of filter for the ambience applied to the direct sound).
Ambience Cutoff Frequency (adjusts the cutoff frequency for filter)

4 Ensemble (a special chorus effect produced by two low-frequency oscillators running at different speeds)

5 Equaliser (three-band, fully parametric equalisation)
Low Frequency
Low Gain
Low Q
Mid Frequency
Mid Gain
Mid Q
High Frequency
High Gain
High Q

6 Flanger (a two-channel effect with full stereo output)
LFO Waveform Type
Manual (adjusts the centre frequency of the flanging effect)

7 Input Mode
Mode (changes input signal from stereo to mono)

8 Master
Effect Level
Total Level
Direct (switches direct sound on or off)

9 Overdrive (a mild 'vacuum-tube' distortion)
Effect On/Off
Drive (adjusts distortion level)

10 Output Mode
Mode (used to select the type of output)

11 Rotary
Rotor Speed Fast/Slow Rise Time: Horn (adjusts the change in the horn's speed of rotation when switched from slow to fast).
Rise Time: Rotor (adjusts the change in the rotor's speed of rotation when switched from slow to fast).
Fall Time: Horn (adjusts the change in the horn's speed of rotation when switched from fast to slow).
Fall Time: Rotor (adjusts the change in the rotor's speed of rotation when switched from fast to slow).
Mic Setting (controls the simulated sound of a microphone located either close to, or far away from, the rotary speaker)
Horn Speed Fast/Slow
Horn Depth
Mix Balance
Rotor Depth
Horn Tremolo
Rotor Tremolo

12 Space Chorus (reproduces the sound of Roland's SDD320 Dimension D processor)

Previous Article in this issue

Graphic equals

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Secrets of the pyramid

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


The Mix - Aug 1994

Donated by: Colin Potter

Control Room

Gear in this article:

Studio FX > Roland > SDX-330 Dimensional Expander

Gear Tags:

Digital FX

On The Re:Mix CD:

04 Roland SDX330 - Lifted Chorus
05 Roland SDX330 - Vintage CE2
06 Roland SDX330 - E.Piano Ensemble
07 Roland SDX330 - Like Buttah!
08 Roland SDX330 - Sizzle On Top
09 Roland SDX330 - Slow Spinner.

This disk has been archived in full and disk images and further downloads are available at - Re:Mix #2.

Review by Nigel Lord

Previous article in this issue:

> Graphic equals

Next article in this issue:

> Secrets of the pyramid

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