ART Pro Noise Gate

Paul White gets the first ART eight‑channel Pro Gate to land in the UK — and discovers that behind the hi‑tech facade, it's a bit of a Harley‑Davidson.

There are processors that add something to a sound — reverbs, delays and enhancers, for example — and then there are others specifically designed to take something away. The most commonly used subtractive device is the noise gate, which has been an essential part of the studio toolkit ever since homo sapiens recorded 'pictures of sound' on rust‑coated strips of yak skin threaded around a vibrating lode stone.

OK, I lied about the yaks, but not about gates being essential pieces of studio kit. Indeed, as today's studio has far more channels and tracks than it used to, gates probably have a more important part to play than ever. Even more of a problem is the number of synths (not to mention guitar preamps), that still chuck out so much hiss and digital grunge that most manufacturers are reluctant to provide technical specifications.

The world and his wife may still be skipping down a digital signal path, but for my money, the best noise gates are still analogue. This latest ART creation provides eight, fully specified analogue gates in a 2U rack with conventional knob control — yet a look at the front panel shows only one set of controls and a suspiciously digital LCD window. So what's going on?

As you've probably guessed, ART have taken conventional analogue gates and placed them under digital control — but in order to retain the analogue 'feel' when setting up, the digital control circuitry is driven by analogue knobs! The clear advantage of this approach is that the same set of knobs can be used to set up all eight gate channels, whereas in a fully analogue system, there would be no alternative to duplicating the whole set of controls eight times.

Another advantage of digital control is that MIDI compatibility can be accommodated, along with the ability to store settings in memory. In the case of the Pro Gate, there are 20 Song memories, each of which holds the settings for all eight gates as a single MIDI patch, plus MIDI real‑time control over the gate threshold level, attack and release times. The Pro Gate also responds to MIDI note triggers, enabling it to handle rhythmic chopping effects under sequencer or MIDI keyboard control. Conversely, a MIDI note can be generated by the gating action, allowing, for example, MIDI drum modules or samplers to be triggered by off‑tape drum sounds being fed into the gate.

The Gates

This machine's gate facilities are equivalent to those of the better stand‑alone analogue units, and I noticed more than a passing resemblance to the Drawmer DS201, in that sweepable, shelving side‑chain filters are included alongside the more familiar threshold, attack, hold, release and range parameters. Internal or external keying is also implemented, as is the ability to link adjacent channels. The key listen mode has a separate output on the rear panel, so that the operator can audition the post‑filter side‑chain signal for any of the gates without interrupting the main gate outputs.

Balanced quarter‑inch jacks are used for the gate ins and outs, with unbalanced jacks for the key inputs, though the software allows the user to switch between balanced and unbalanced operation without incurring any level changes. Hard relay bypassing connects the inputs directly through to the outputs whenever a gate is switched out of circuit.

The Hardware

Everything fits easily into a 2U rack unit, with all the connections on the rear panel, including MIDI In, Out and Thru. Power comes directly from the mains, and a large 2‑line x 40‑character display sits directly above the dedicated controls for Key Filter, Threshold, Attack, Hold, Release and Range. To the left of the display are eight green LEDs which, perversely, light up when the gates are closed rather than when they are open, while eight red LEDs show which gate is selected for editing (dedicated buttons make gate selection easy). A single Bypass button operates on whichever gate is selected, while a further three buttons relate specifically to the side‑chain filter section. These are labelled Key Listen, Source and Frequency. Source selects between internal (self) and external (key) triggering, while Frequency toggles the Key Filter control between adjusting the high‑pass and low‑pass side‑chain filter frequencies.

The Pro Gate is still an analogue gate at heart, despite the digital side‑chain control.

In normal use, setting up is simply a case of choosing a gate with the Select button, then using the six knobs to set up the gate in the usual way. The green lights come on when the gate is closed, a protocol which could spell disaster on British roads, even if the Japanese might understand it.

To the right of the display is a large data wheel, used to scroll through different menus for editing or setting up. For example, when you're in the normal 'setting up gate parameters' mode, it moves through the Overview screens, which show (respectively) the linking, int/ext keying and bypass status for all eight channels at once. This control also accesses the Save and Recall Song page.

In Link mode, the Select buttons can be used to link the operation of any gate to the one immediately to its left, with the leftmost gate of any linked group always the master. Similarly, in Bypass mode, the Select buttons are used to bypass the individual gates, whereas in key mode, the Select buttons toggle between internal and external trigger. This might seem like a lot to remember when you see it written down, but the reality is that the gates are just as easy to set up as their conventional counterparts, and everything is designed to be very intuitive.

Beneath the data wheel are the final two buttons, Menu and Select, which are used to navigate through the programming options and to select parameters for changing.

On The Menu

Pressing the Menu button steps around the Channel, System and MIDI menus, but each page also has the word 'Back' on it, so you can move back to the page you've just come from. This facility is also used when you want to cancel any new information you've just dialled in, but not confirmed. The Channel setup menu allows any MIDI note to be chosen to trigger each of the gates, as well as setting up the MIDI controllers for real‑time Threshold, Attack and Release control. While I can't foresee many applications where I might want to use a gate as a MIDI‑controlled performance tool, this facility does allow computer sequencer users to create their own gate control pages very simply. For example, you could create a few controller faders on an Environment page in Logic. Channels may also be named in this menu, and settings copied from one channel to another. It's also here that you get to choose which MIDI note each gate sends out when it's triggered.

The System menu accesses the usual display angle adjustments, as well as offering the facility to lock the front panel parameter change controls — a must in installations. Song data can be saved, named or recalled from this menu, and you can even switch the inputs and outputs from balanced to unbalanced operation.

The MIDI menu is used to select the system MIDI channel, the MIDI mode, and to set up or edit a MIDI program table — which lets you assign any program change number to each of the 20 user memories or 'Songs'. MIDI dumping and loading of Songs, either individually or en masse, is also initiated from this menu.

In Use

It really only takes a few minutes to find your way around the Pro Gate, and the menu structure is very straightforward compared to what you might expect on a MIDI synth or effects unit. The use of dedicated knobs for the familiar gate controls is a big help, and though these don't seem quite as responsive as true analogue controls, they are still satisfactory, and infinitely preferable to menu/cursor driven systems.

The Pro Gate can be set to a minimum attack time of 20 microseconds, and tests with drums and drum machine sounds confirmed it to be very fast indeed. The hold parameter, plus a small amount of built‑in hysteresis, prevents the gate from chattering, and as far as I could tell, the gate doesn't add any perceptible noise or distortion to the signal being processed. In all respects, including the key filter action, the Pro Gate performs like any other well‑designed analogue gate, and has the advantage that you can link together as many of the gates as you like, for tasks such as synchronising backing vocalists who have a habit of finishing at different times.

What you don't get on most analogue gates is the MIDI trigger or real‑time control function, and both worked flawlessly. No glitching occurred if parameters were changed while a sound was being processed, so my guess is that the gate waits until it next closes before updating its parameter values. Indeed, the only thing I didn't entirely understand is why the currently selected patch — they do insist on calling them Songs ‑‑‑ isn't displayed somewhere on the main page. You also have to remember to save your settings as a Song, especially when you're connected to a sequencer, as you only have to send one patch change message by accident, and the Pro Gate reverts to the previously called‑up settings, or jumps to a different patch altogether. In this respect, a couple more dedicated buttons for faster saving would have helped, but even as it is, nothing in the menu structure is very far away.

Summary

Given the constraints of handling eight gates from a single set of controls, ART have done an excellent job, and after your first session or two, you're unlikely to have to refer back to the mercifully concise manual. The Pro Gate is still an analogue gate at heart, despite the digital side‑chain control, and as such it behaves in a transparent and reasonably predictable manner. Better metering might have helped, by giving you a clue as to how far away from the current threshold setting the input actually is, but in all fairness, few conventional gates provide this either.

The most useful MIDI feature, in my opinion, is the ability to chop sounds using MIDI note information, with the MIDI note output feature coming a close second. I can't imagine many situations where I'd want to store a set of eight gates to allow me to recreate an archived mix, but it is handy to be able to set up and store the MIDI parameters and key/link options for one or two specific requirements.

There's little to dislike about the Pro Gate. ART have resisted the temptation to include too many facilities, though MIDI‑triggerable panning would have been useful, as would conventional ducking. Ease of operation doesn't suffer significantly because of the shared interface, and the ability to rig up control from a sequencer using MIDI controller data has potential. If you need eight full‑featured gates with MIDI capability, this could be one of the more useful and cost‑effective options.