At one time, I owned an Alan Smart C2 compressor, but these days, I mix in the box and rely on the Waves SSL compressor plug-in, so I was excited to try out the VCA-based 7720, which relies on THAT Corporation circuitry and low component count to purportedly sound like its SSL and Smart brethren. Out of the box, the unit feels solid and looks nice with its silver faceplate and the same large, stylized knobs found on other Chameleon Labs gear. Across the front, the unit sports power and bypass switches; a recessed VU meter with a meter-select switch; sidechain in/out with a choice of HPF frequency; variable threshold; stepped attack, release, and ratio knobs (including a very useful 1.5:1 setting); and variable output. The back of the unit sports balanced I/O, a balanced sidechain input, and two power connectors. The unit can be powered by either the supplied inline 24 VAC adapter or the optional rackmount CPS-1 dual DC power supply. Running the unit in bypass mode, the signal seemed completely untouched.
If you're looking for a compressor with color and character, this is definitely not your cup of tea. Initial tests running a mix through the 7720 with a ratio of 1.5:1, attack of 0.3 ms, auto release, and the threshold set so the meters were kissing about 4 dB of gain reduction, the unit exhibited remarkable transparency, nicely gluing the mix together without imparting any kind of color whatsoever. Side-by-side with a Smart C2, the 7720 seemed less gritty and cleaner yet still provided the basic sound these compressor designs are known for. Fiddling with the settings, I was able to get both units to sound very similar with the Smart being a tad brighter on its output. Next to the Waves version of the SSL bus compressor however, I would have to say that the 7720 won easily. The compressed mix through the plug-in sounded smaller and somewhat flat next to the 7720. Even though the plug-in somehow had more of the SSL "character", the 7720 sounded much more open and pleasant.
Where things get interesting however, is the one thing that sets this unit apart from the others-the sidechain function. Not only can it accept an external source, but in normal operation, its coolest feature is the ability to filter the signal that feeds the detection circuit, not the main audio. Using the high-pass filter on bottom-heavy material really allows the compressor to breathe nicely, opening up the sound significantly and just knocking off the top of the mix while retaining the bottom-end girth. The more I used this feature, the more I pushed it, ending up consistently at the 200-440 Hz settings. This feature alone is worth the price of admission.
More extreme ratio and threshold settings also fared well; the unit really pumps nicely on smashed drum overheads as well as on the complete drum submix. The 7720 isn't something you want to drive too hard however; doing so resulted in not so pleasant distortion, so feeding it respectable levels is definitely advised. I also used the 7720 as a tracking compressor on various sources (you can use it as a mono compressor by utilizing only the left channel I/O) and found that on vocals and acoustic guitars, it performed very well, with a nice transparency making it very useful for those duties. The sidechain option came in handy on those sessions as well. One of the best tracking applications I found for it involved using it to control an acoustic piano (my beautiful Steinway Model O grand). This is hands down one of the best piano compressors I have ever heard; transparency, openness, and the sidechain filter again being the key here.
There isn't much not to like about this unit. I do wish the meter were better as it is hard to read from an angle due to its recessed nature, but for the price I'm not complaining. I would have to say Chameleon Labs has a real winner here; the 7720 is equally at home being a very good VCA bus compressor (especially with the sidechain feature and low 1.5:1 ratio) as well as a nice, transparent tracking compressor. At this price, one can easily afford to have more than one unit performing various duties around the studio. Even though I mix completely ITB now, I still want one for tracking and for smashing the crap out of drums and stuff like that. At a street price of $654, you really can't go wrong. ($679 MSRP; www.chameleonlabs.com)
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