Another inovative product from Electrospace in the form of a digitally controlled noise gate.

The Gate, as it is modestly entitled, is a dual channel rack mounting gate with a difference. Not only does it offer all the usual parameters including side chain filtering, it also offers a novel digital control section and the use of Aphex VCAs ensures low noise, low distortion operation and good transient response.

Like other Electrospace units, this one is housed in a conventional package but with a degree of styling and mechanical refinement that makes it instantly identifiable as one of their products. The black paintwork is effectively contrasted against the yellow legend and the panel layout incorporates a great number of controls without looking unduly cluttered.

Both the inputs and the outputs are electronically balanced and utilise standard XLR connectors, though these are wired as pin three hot and not pin two as is the generally accepted convention. This shouldn't cause a problem because both the input and output sockets are of course wired to the same convention so the emergent signal will always be in the correct phase. All the other connections are control inputs or outputs and are on standard unbalanced quarter inch jacks.

As there is more to this machine than there is to the average noise gate, I'll go through the controls section by section.

Key

In normal operation, a gate analyses the signal input to provide the control or key signal and in its simplest form, this consists of monitoring the input signal level and opening the gate once the signal exceeds a set threshold. However, this control signal, or key as it's often called, may be derived from a signal other than the gate input and in this way, a bass guitar can be gated by a bass drum for example. This is an old trick often used to tighten up the sound of a rhythm section but it serves to illustrate the point.

In the case of The Gate, the key signal may be derived from the audio input or from the Key Input on the rear panel and this is selected by the Int/Ext switch on the front panel. Like the popular Drawmer gate, this model allows the key signal to pass through a filter so that unwanted portions of the sound can be attenuated to reduce the likelihood of false triggering. The filter section takes the form of two independent filters, a high pass and a low pass, which allows the user to home in on the desired sound. For example; if you're trying to clean up a snare drum track but are suffering from false triggering caused by spill from the hi-hat, you can use the filters to attenuate the high frequency end of the control signal. Whilst this won't eliminate the hi-hat, it will reduce its level so that careful setting of the Threshold control will enable you to lock onto the snare drum and ignore the hi-hat.

Envelope

The heart of the noise gate is a voltage controlled amplifier (or VCA) and the gain of this device is set by a control voltage derived from the key signal. I say derived because the key signal is not the control voltage as such. The operation is closer to that of the envelope shaper within a synth, as you can adjust the attack and release time of the gate as well as the hold time and the amount of attenuation when the gate is in its off mode. In effect, the key signal triggers this envelope shaper. Attack is variable from 50mS to 1 second and decay or release from 5mS to 3 seconds. Hold is variable from 1 mS to 5 seconds and, in order to give a visual clue as to what is going on, the Yellow LED which forms part of the front panel display dynamically displays the envelope.

As well as its normal gating function where the presence of a signal opens the gate, the system may be operated in the inverse mode to create ducking effects. What happens here is that a signal high enough to exceed the threshold will in fact cause the gate to close and by using the Depth control, the desired amount of attenuation may be obtained. An application of ducking is where a voice applied to the external key input causes the level of a music track to fall so that the voice can be heard. When the voice finishes, the music returns to its former level at a rate determined by the envelope control settings. Again the normal or invert modes of operation are displayed on the front panel in this case by either a red or a green LED. The red LED is on when The Gate is in the Attenuate mode and the brightness of the LED is linked to the setting of the Depth control.

Monitor

All these facilities are fine of course but you really need to know exactly what signal the system is responding to and that is where the Monitor section comes into its own. There's a monitor switch which determines whether you get the Input, VCA output signal or the Key signal at the output. In normal use you would of course select the VCA signal but for setting up, the Key position lets you hear the key signal and the effect that the filters have on that signal. This means that when you are setting up, you can hear what effect your filter settings have and adjust them accordingly to tune in the required signal whilst minimising any unwanted spillage.

Digital System

So far then the machine appears to be a refinement of the standard noise gate, but the digital section sets this unit apart. The circuitry incorporates a counter which can count key signals, that is every time a signal exceeds the threshold level, it steps the counter. When you first turn on the gate, it defaults to its normal mode of operation and you'll see that the yellow LED is illuminated. Each of the two numeric displays has an up/down switching arrangement and when numbers are entered into these, the system enters digital mode. Each display is variable from 0 to 9 and the first one determines for how many threshold transitions the gate will stay open while the second one for how many it will stay closed. Pressing the Reset switch sets the counters back to zero and puts the machine back into normal mode. In order to help in setting up, the display once again comes to the recue and a red LED flashes briefly every time a threshold transition is detected. To initiate a digital sequence, it is only necessary to push the start switch up and the sequence will start from count one; if the switch is held up, the counters will not start but the trigger LED will continue to count which helps when you are cuing in to a sequence.

You may wonder what the use of this digital section is and I must admit that it's a little bit specialised but it does give you the opportunity to plan a gating operation that occurs every four or five beats rather than one that works on every beat. Tricks could include reverb on drums that only appears in the second half of each bar or you could set the system up to completely remove every other drum beat.

Digital/Analogue Link

The front panel sports a digital/analogue switch and when this is set to Analogue, the right hand side control system is disabled and both channels track together. Again the display tells us that this is the case by flashing up yet another LED.

In the Digital position however, the right hand control system operates as normal except that it's switched in and out by the digital system. By setting this switch in its centre position, we get back to the state where both gates are independent. There are three external jacks associated with the digital part of the system and these fall into the scheme of things as follows:

External

The Digital External Trigger is a switched jack, and when nothing is connected it causes the counters to work from the left hand channel threshold circuitry. When a jack is inserted, the digital counters follow the external source. This could be the trigger pulses from a drum machine or a recorded drum track. There's also a digital control output socket which allows other Gates or the less sophisticated Strate Gate to be slaved up to the same digital counter system.

Thirdly comes the Digital Control socket and this may be used as a slave input or you can switch the gate control in and out from an external source. When a low signal is connected, the system's control signal is disabled. All these digital functions require or provide a level of between 2.5v and 15v to operate.

In Use

As a conventional gate, this operates as one might expect, though use of an Aphex VCA undoubtedly gives a better performance in terms of noise and distortion than a conventional FET circuit. Also, the Aphex chip has an incredibly fast transient response and so can handle anything that the control circuit can throw at it without so much as blinking. Because these specialist chips are relatively expensive and require a fair amount of ancillary circuitry, the cost is higher than that of a FET system. Even so, the Strate Gate (which is The Gate without the digital control system) is attractively priced when compared against other quality gates.

The side chain filtering is a most welcome addition because in a busy studio, the time wasted patching equalisers into the side chain of a gate is often an unwelcome hassle. In use, the gate certainly sounds smooth and it's fast enough not to destroy transients. Like all such devices, However, you have to set it up intelligently if you are going to get the best results. For example, a sound with a slow attack may cause a click if the gate attack is set to be too fast, as the gate may switch on part of the way through a cycle, but on the other hand, a long attack time on a drum sound is going to destroy the leading edge of the sound. Also you have to consider the effect of side chain filtering. If you have rolled off all the top unnecessarily, the rise time of the key signal may be such that it crosses the threshold later than it should, so resulting in the start of a sound being cut off. Still, a gate of this sophistication is likely to sell into a market aware of these considerations and these basic factors apply to any other gate with this type of control system.

The digital side also works well, though you may be limited by the single decade of counts provided. However, it does its job and it's up to the user to think of a use for it. It's because this feature is somewhat specialised that many firms will buy Strate Gates and hire in the all singing model only when it's needed. This feature will probably be of more use to those working with electronic drums or sequencers where trigger pulses can be programmed to signal the open and close points needed. In this way, The Gate could be used to provide a limited form of automation by automatically turning a reverb unit on and off during a mix at predesignated cue points.

Conclusions

The Gate is an expensive unit but it performs very well and should be much sought after by professional studios and hire companies. Its performance should make it compatible with digital recording in terms of its noise performance, but the digital control system is a unique feature that will be invaluable to some and go totally unused by others.

If you fall into the later category, the Strate Gate offers the same exemplary performance but without the digital frills and is very reasonably priced.

The Gate then is another high quality British product and in many ways a flagship product. It's interesting to note that it looks good as well as working splendidly, which is not always true of home grown gear, but for my money, the Strate Gate represents the best value for money and should sell in substantial quantities.

The Gate costs £595 and the Strate Gate £325 including VAT.

Further information is available from: Britannia Row Equipment Ltd, (Contact Details).