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LA Audio GCX2

2-channel Compressor/Gate By Paul White
Published February 1997

This UK‑designed and built processor offers two channels of easy‑to‑use compression and gating for under £200. Paul White's backing Britain.

Over the past few years, the amount of competition in the audio processor market has succeeded in forcing prices down to rock bottom, and with budget brands such as Behringer soaking up a hefty share of the low‑end business, companies normally associated with mid and high‑end products have also shifted their corporate gaze to the mass market. One such company is LA Audio, who started out building products like the Classic Compressor, then designed lower‑cost spin‑offs such as the 4x4 compressor/gate (reviewed SOS July 1996) and the resplendently green LA Lite range (reviewed SOS December 1994 and November 1995). The new GCX2 compressor/gate, reviewed here, represents a further significant step down in cost: LA Audio's engineers have evidently concentrated on trimming away unnecessary features and making their designs even more cost‑effective to fabricate.

The GCX2 could be viewed very much as an entry‑level processor, though (for the benefit of the more discerning user) it still features balanced XLR ins and outs at +4dBu, as well as balanced TRS jacks at ‑10dBV, plus TRS side‑chain insert jacks. On a personal level, I'd have preferred to see the jack ins and outs running unbalanced, simply because most consoles have unbalanced insert points, and running unbalanced to balanced (and vice versa) often results in a loss of signal level. However, the GCX2's output stage is designed so as to avoid this problem.


Essentially, the GCX2 is a two‑channel processor, where each channel comprises one stage of gating and one stage of compression. Both the compressor and the gate operate from the same side‑chain RMS level detector, which in turn monitors the input signal level. This is a slightly unusual arrangement, as most compressors derive their control information from the VCA's output rather than from the input, but as this is how some of the older vintage models got their dramatic sound, LA Audio may have adopted it for this very reason. The 6‑LED gain‑reduction meter monitors the compressor action, while a single green LED shows what the gate is up to. When the gate is bypassed, the green LED dims but continues to monitor the gate action.

Like other LA compressors, the circuitry uses a soft‑knee circuit combined with a variable ratio, so that as the signal approaches the threshold level, the gain reduction ratio increases progressively to its set level, rather than coming in all at once. As a rule, this leads to a smoother compressed sound. Threshold adjusts the level at which compression starts, while Ratio is adjustable from 1:1 (no compression at all), right up to 20:1 (heavy limiting). Both the gate and compressor have their own Bypass buttons, but the controls are far simpler than you'd expect to find on most studio processors. For example, there's no attack or release control — just an 'auto' setting with switchable Slow and Fast response times. In Slow mode, the attack time varies from 10ms to 100ms, depending on the transient nature of the input signal, while the release time is fixed at 3s. In Fast mode, the attack can range from just 5ms to 70ms, with the release set at 0.5s. The usual output gain control is provided to make up for any gain loss due to compression, and the centrally‑mounted Dual/Stereo button allows both compressor channels to be linked for stereo operation, when required. In this mode, both channels are set up using the compressor controls of channel 1. The gate section combines the gate side‑chains in such a way that both channels open if either side is triggered.

If the compressor is straightforward (and it is), the gate is even simpler, featuring just two knobs and a Bypass button. The Threshold control sets the level below which gating takes place, while the Release control adjusts the gate release time from Fast to Slow. In Fast mode, the release time is a snappy 30ms (suitable for drums), while in Slow mode, the release time is a leisurely 3s, to ensure that gently‑decaying sounds aren't snuffed out before their allotted time. The gate range is fixed at 80dB attenuation — which is as close to complete muting as makes no difference — and even though the gate attack time is preset to fast, I didn't notice any clicking when gating non‑percussive sounds. Conversely, on digitally‑recorded drums, the gate opened fast enough to keep the transient edge of the sound intact.


Because of the simplified control system LA Audio have adopted for the GCX2, the unit is very easy to set up, yet you rarely feel that you've lost control in an area where you really needed it. For general‑purpose gating and compressor applications, the GCX2 provides all the control you need, though for more specialist gating tricks — such as creating gated drum sounds, using external keying, or working with sounds where side‑chain filtering is needed — you really need the 4x4 or a dedicated full‑function gate such as Drawmer's DS201.

Modest amounts of gain reduction can be achieved without incurring any obvious side effects, but if you start to exceed 6 or 8dB of gain reduction, the sound begins to take on a warm, obviously‑compressed character, where the compression moves out of corrective territory and instead becomes a creative effect. All the usual sound sources, including voice, bass guitar and acoustic guitar, were wheeled out for testing, and all came out pretty well. Performing the same tests with a more esoteric compressor (costing almost three times as much) produced a better‑focused result, with less effect on the transient definition of the material being processed, but considering the very low cost of the GCX2, it performed extremely well and produced warm, musical results.

The gate side of the GCX2 is positive and straightforward to set up, and in most situations, that's all you could ask for. Indeed, I can see the GCX2 being taken up by the live sound user, precisely because you don't have to spend ages fiddling with it. It doesn't have the flexibility of a gate with side‑chain filtering or one with separate attack, hold and release times, but for routine clean‑up work, it gives no cause for complaint.


While those of us who have been recording for a long time prefer to buy fewer pieces of really high‑quality gear that will deliver first class results and will last a few years without becoming obsolete, I recognise that there is a need for a 'more bang for the buck' range of outboard gear that combines respectable audio performance with ease of use. Seen in this context, the GCX2 offers extraordinarily good value for money, and it's capable of producing fine results, providing you don't ask it to do anything too far out of the ordinary. Indeed, for those not experienced in setting up compressors and gates, there's a better chance of getting good results from a box like this than from something that provides all possible functions and facilities.

To sum up, the GCX2 is undoubtedly a good compromise between circuit quality, ease of use and build quality. The styling is a great improvement on most budget equipment, and the inclusion of properly‑balanced XLR inputs and outputs is appreciated. Indeed, LA Audio are to be applauded for bringing to market a home‑designed, home‑built product that is able to compete on price with mass‑produced, built‑in‑China imports.


  • Inexpensive.
  • Controls easy to use.
  • Smooth, musically useful sound.
  • Stylish.
  • Includes balanced XLR inputs.


  • No complaints considering the price.


The GCX2 is an excellent entry‑level gated compressor that still wouldn't be out of place in a serious project studio. The stripped‑down feature set also makes it easy for newcomers to get to grips with it.