Kjaerhus Audio GCO-1

March 14, 2005

Sometimes, it’s the smaller software companies that produce the real gems, and this is one of them. The GCO-1 “Golden Compressor” ($118 direct) VST plug-in for Windows 2000/XP gives you more than just a kickin’ compressor/expander. This plug-in is almost like a compressor construction kit, where you can pick the best vintage or modern compressor characteristics you like, and then create a custom preset incorporating that particular sound.

For example, the GCO-1 offers five envelope types (Classic, Smooth 1, Smooth 2, Opto, and Pumper) that emulate the different gain-control elements used in various compressors. You can emulate the relative transparency of opto-based processors, or make the sound “pump and breathe” like some compressors did during the psychedelic ’60s. (When a compressor makes a huge change to the input signal—say, 12dB or more—any noise will rise and fall along with the compressed signal level, giving the impression of breathing. A too-long release time, however, can “lose” lower-level signals as the compressor stops reducing gain, producing the anomaly known as “pumping.”)

With extra goodies such as a subsonic input filter, the ability to adjust curve linearity, variable knee (hard knee for a sudden onset of compressor when a signal reaches the set threshold, or soft-knee for gradual gain reduction), and a 3-band EQ in the detector section for frequency-dependent compression (along with a variable filter to remove ultra-low frequencies), you have a tweaker’s dream. Of course, all of this marvelous sound-sculpting power is also a possible drawback for compression neophytes who may get lost in the plug-in’s high-level parameter controls. Or, heck, you can just experiment and be delighted or horrified at what each of your uneducated tweaks produce! Fortunately, there’s good documentation (if you do happen to care about what you’re doing), and the controls are laid out in a simple and ingenious hierarchy so that novices can grow into the feature set over time. Here’s the deal: The GCO-1’s top controls provide the essential compression parameters that are familiar to basic hardware compressors (and even some stompboxes), and the lower set gets you into deep and detailed editing.

At present, the GCO-1 is only available online through the Danish company’s Web site. However, Kjaerhus Audio—which was founded in 2003 by Torben Kjaerhus—offers curious and skeptical types a free, 14-day “try before you buy” version. My advice is: Don’t click for the download unless you’re prepared to spring $118 for the fully licensed version, because the more you use the GCO-1, the more you’ll realize just how versatile it really is.


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