Test Drive: The A.R.T. DR-X Digital Multi-Effects Processor

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by Jerry Vigil

The processor wars continue! In February of last year, we did a Test Drive on A.R.T.'s MultiVerb. Four effects at once! Wow! A little over a year later, we look at one of A.R.T.'s latest multi-effects processors, the DR-X. How many effects at once? Ten! That's right, up to ten effects at once -- perfect if you can even think of ten effects you would want to use at the same time. At any rate, if it is "how many simultaneous effects" that is your first question about a multi-effects processor, the DR-X has a big answer and a lot of extras to go with it.

The DR-X boasts having over sixty different effects to choose from. What this boils down to is twenty-six primary algorithms. Some of these algorithms have more than one effect available. For instance, the Expander/Gate algorithm counts as one algorithm, but it actually has three effects, an expander, a noise gate, and a filter envelope. Other algorithms, such as the Reverb 1 algorithm, count as one primary algorithm, but have additional secondary algorithms of their own. In the case of the Reverb 1 algorithm, the secondary algorithms are Hall-1, Room-1, Plate-1, and Vocal-1.

Stay with us now. Of the 26 primary algorithms, six are primary reverb algorithms, each with four secondary algorithms providing choices for "types" of reverb. This gives us a total of twenty-four different reverb effects. Eight more of the primary algorithms are delay algorithms. Again, some of the delay algorithms have secondary algorithms of their own offering different "types" of delay. When you look at the number of different delay effects you can have, the number is well over twenty.

Together, reverb and delay effects total nearly fifty of the sixty effects available on the DR-X. The primary delay and reverb algorithms consume 14 of the 26 primary algorithms. So, when you hear about a processor having over 5000 effects, bear in mind that it might have some 4950 delay and reverb programs. Having said this, let's go on to say that these numerous delay and reverb effects are not to be taken lightly. The 16-bit, full bandwidth reverb programs are clean and versatile. Reverse reverbs are available as are gated reverbs. The delay programs are equally as clean and versatile. As you know, the amount of memory inside any digital processor is going to dictate the maximum amount of delay time available. In the DR-X, a maximum of two seconds of delay is possible. A nice addition to the delay algorithms that you don't see on many processors is the Tapped Delay. Up to seven taps are available with a total delay time of 1.8 seconds. Used in the stereo mode, the Tapped Delay algorithm can provide up to 14 repeats of an input signal, each bouncing back and forth between left and right channels. We've sampled a few of the effects from the DR-X and put them on this month's Cassette. The Tapped Delay effect des-cribed here is on The Cassette using the factory program called "Train Comin' Delay."

The maximum two second delay of the DR-X also means you have a sampler of sorts with a two second sample time. Three of the 26 primary algorithms are sampler algorithms. They are Sampler-S(hort), Sampler-L(ong), and Sampler+PTr (PTr=Pitch Transposer). The first offers a maximum sample time of 1.7 seconds. The second and third, a full two seconds. The algorithm with the shorter sample time is used for combining the sampler with reverb programs (the reverb programs need some of the memory for themselves). The sampler itself is very easy to use. Record Start can be activated three ways: 1) manually by one of the panel buttons, 2) automatically as soon as audio is sent to the sampler, or 3) by MIDI messages. When using the Sampler+PTr algorithm, the pitch of the sample upon playback can be altered. The pitch parameter can also be controlled via MIDI. More on MIDI control later. Sampling frequency is 44.1kHz for full bandwidth recording. Samples can be edited to a degree, in that the sample length can be shortened after recording it. The sample start point can also be edited but only up to one-tenth of a second into the sample.


Other digital effect algorithms of the DR-X include Low Pass Filter, Flanger, and Chorus. These pretty much speak for themselves. There's also a panner with variable panning depth and rate.

The DR-X has one primary algorithm for pitch shifting. The range of pitch shifting is two octaves. Course and fine adjustment parameters are available, as well as a feedback or REGENeration parameter. A nice touch to the pitch shifter is the TYPE parameter. Here you have a choice between SMOOTH, NORMAL, and QUICK -- three secondary algorithms. This parameter lets you select three ways in which the pitch shifting is processed. Choosing SMOOTH selects a secondary algorithm with a longer delay time which results in more glitch free pitch shifting. If the delay presents a problem in your application, the NORMAL and QUICK settings have shorter delays but are apt to produce glitches more frequently.

What we've described so far are the "digital" algorithms. There are four more primary algorithms that fall into a category called "Dynamic Effects." These effects are digitally controlled, but they're processed in the analog domain. The four Dynamic Effects algorithms are: Harmonic Exciter, Equalizer, Compressor/Limiter, and Expander/Gate. The Harmonic Exciter adds a nice "bright-ness" to any audio passed through it. The Equalizer is a three band equalizer with preset center frequencies and bandwidths. Center frequencies are 100Hz, 1KHz, and 10KHz. The Compres-sor/Limiter algorithm offers a fixed peak limiter with the threshold set at +3dB, and it can be defeated. The compressor offers a SLOPE parameter to select the compression slope, a DRIVE parameter to adjust the gain to the compressor, a RELEASE parameter, and an OUTPUT gain parameter. The Expander/Gate algorithm has three effects in one algorithm. The expander and noise gate can be used separately or together. The third effect is a high "Q" sweepable low pass filter.

The DR-X comes shipped with 110 factory programmed presets and has room for 90 more. For those of you who prefer buying a processor and mainly using the presets, the 110 factory programs in the DR-X do a good job of illustrating the variety of effects of this little box. As mentioned earlier, there is an audio version of this Test Drive on this month's Cassette. We selected a few of the factory presets and stepped through them with a mike to give you an idea of what the DR-X can do.

Programming the DR-X was much simpler than first expected. To create a patch from scratch, you simply select an empty memory location then push the ADD EFFECT button. On the LCD screen, you are shown the effects or algorithms that are available for programming. If you don't want the effect displayed on the screen, you just continue to hit the ADD EFFECT button until you see the effect you want. By pressing the RECALL/ENTER button, you select the effect and place it on line so that any audio going to the DR-X is immediately sent through the new effect. Some algorithms cannot be combined with others. Once you choose a particular algorithm, the unit automatically defaults to display only those remaining algorithms that can be combined with your previous choices. Once you've selected all the effects you want in your program, you then use the two SELECT and two VALUE buttons to scroll through each of the parameters for each effect, adjusting each to suit your taste. Changes are made in real time, so you hear each change as you make it. When you have everything set as you want it, you can push STORE to record the program in memory.


It's hard to say exactly why the DR-X seemed easier to program than other multi-effect processors, but it did. This might have something to do with the fact that while there are many parameters available for adjustment, there aren't so many that programming gets confusing. For example, while the reverb algorithms COULD have offered several more parameters for adjustment, they only offer those that are the most important. That means less button pushing as you scroll through parameters and less reading of the manual to determine exactly what certain parameters even do. For some serious applications, the limited number of adjustable parameters might be a hindrance, but for radio production, there is more than enough control over each of the algorithms. It's a nice box for someone who doesn't want to spend a week with their nose in the manual before they start programming the unit.

The DR-X is fully MIDI controllable, from program change to control over individual parameters in any of the algorithms. The DR-X can have up to eight parameters per preset connected to a MIDI device or controller, and all eight parameters can be adjusted simultaneously. You can quite easily set up a delay/reverb/pitch program that enables you to adjust delay time with the pitch wheel of your keyboard while reverb decay is adjusted by the modulation wheel and pitch is adjusted by hitting various keys on the keyboard.

The DR-X has unbalanced stereo inputs and outputs. It is not a true stereo processor in the sense that two individual processors are working on each channel, but if you have a 50/50 wet to dry mix at the outputs, the dry portion of the mix will remain in true stereo. The effects themselves are applied to a sum of the left and right inputs. If the selected algorithm is a stereo effect, the stereo effect is then mixed with the true stereo direct signal at the output. By the way, the mix is controlled by a fader on the front panel -- fast and simple. Also, many of the effect algorithms offer their own output level parameter so you can vary the amount of each individual effect in presets with more than one algorithm in use.

The thing we found most pleasing about the DR-X was the cost, a mere $629. We should mention that there are three other new processors available from A.R.T.. They are the SGE Mach II, The MultiVerb III, and the MultiVerb LT. You've probably heard about the original SGE. This was the unit introduced last year that offered an amazing nine effects at once. The new SGE Mach II offers twelve and lists for $749. Aside from 12 simultaneous effects, the only major difference between the SGE Mach II and the DR-X is the SGE Mach II's distortion algorithm commonly used with electric guitars.

The MultiVerb III is basically the same as the DR-X minus the dynamic effects and the sampler. You only get four effects at once with the MultiVerb III, but it lists for an even lower $529. The MultiVerb LT is basically the same as the MultiVerb III, but it is designed more for the person who doesn't have time to mess with programming the unit. In fact, you can't program the unit. Instead, the LT offers 192 factory programmed presets that cover practically every conceivable combination of effects available in the MultiVerb III. The programming has been done for you. All you do is pick the effect and set a mix. The price tag on the LT is a mere $299.

These four boxes come from A.R.T. -- Applied Research and Technology. Their research and technology have certainly been "applied" to creating very good multi-effect processors at very affordable prices. If there were sacrifices made to keep the prices lower than the prices of more popular processors in the same class, we can't find them. Our hats are off to A.R.T. and their new line of digital multi-effect processors. Hmmm... I wonder what they'll come up with next month?

For more information on the A.R.T. line, call (716) 436-2720.

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