Chameleon Labs 7720 Stereo Compressor(2)

Chameleon Labs’ 7720 1U rackmount Stereo Compressor is sparking a lot of conversation amongst “pro-level” recording enthusiasts. While there are plenty of stereo compressors on the market, the 7720 appears unique in that it resembles certain high-end hardware compressors in functionality (such as the SSL Buss Compressor), yet it streets at a modest price. So we grabbed a unit to see if we could answer the obvious question: Does the 7720 really offer professional sound quality at a low price, or is this just another cheap knockoff?


Electronically balanced and utilizing THAT Corporation VCA circuitry, the 7720 is based on what Chameleon Labs calls a “trusted design” (hint: re-read the intro). The best part is that Chameleon Labs has made a few tweaks to said “trusted design”—tweaks that were informed by consumers during the design process. See if you can spot them, then head over to, log in to our “Letters to the Editors” forum, and tell us what the changes are—and if you think they were a good call.

Front panel controls are Threshold (–20 to +20), Attack (0.1, 0.3, 1, 3, 10, 30msec) Release (0.1, 0.3, 0.6, 1.2secs and Auto), Ratio (1.5:1; 2:1; 4:1, and 10:1), and Output. Additionally, the 7720’s Meter knob lets you meter, via a retro VU meter, either the channel’s input level, output level, or compression amount; other features are a compressor in/out switch, Sidechain switch (accessible via a rear XLR jack), and a High Pass Filter for the detection circuit (it doesn’t affect the audio itself) that will EQ your selected frequencies down 3dB with a 12dB/octave rolloff (cut settings are 60, 90, 130, 200, and 440Hz).

Around back, you’ll find the XLR ins and outs. (Note that while the 7720 is a stereo compressor, it can be used as a mono compressor by simply using only the left in and out.) You’ll also notice the two power options: DC or AC 24v. While the unit comes with a mid-line power supply—not a wall wart, but an outboard AC transformer—the optional CPS-1 rackmount dual power supply ($110 MSRP) includes grounding.


After pulling the 7720 out of its box, I noticed there was no power plug ground. When I read in the manual that “DC filtering and regulation is accomplished inside the 7720 itself,” things became a little more clear, and when I failed to detect any ground hum or buzz, my fears were allayed. But a word to the wise: Purchase the CPS-1 if you’re using dirty power, or hear any noise in your audio lines.

I decided to test the 7720 in a singular scenario that showcased one of the more practical and widespread applications for a stereo compressor: compressing a drum submix. This particular submix consisted of kick, snare, toms, and a bit of overheads. The goal was to compress the submix, then add it under the original tracks to “glue” the drum sound together.

According to the Chameleon Labs site, the 1.5:1 ratio setting “allows the user to maintain control over the dynamics of the input signal without squashing the life out of the mix.” Giving this setting a try, I have to echo that statement. This controlled the level of the drums without imparting that pumping, pulling sound. This is a great setting when using the 7720 as a bus compressor across your entire mix.

However, for a submix “helper,” I needed a squashed sound, so I set the ratio to 10:1, threshold to –12, attack to 0.1, used Auto release, set the meter to “Comp”, and watched the needle get knocked all the way down to –10. The result was a healthy pump that added a nice effect when mixed under my original drum tracks.

I wanted to see if the high pass filter could control the pumping so that it wasn’t so overbearing. Setting the filter to 200Hz took away some of the pump’s “attack” (presumably because it was knocking down some of the “mud” frequencies in the kick drum). My final setting, however, was 440Hz—it kept just enough pumping for a good effect without letting it get out of hand.


I feel very comfortable saying that the 7720 is worth a whole lot more than what Chameleon Labs is charging for it. It offers some unique features that can’t be found elsewhere, and the unit’s sound quality ranks up there with other compressors that charge five times the admission fee. I will be buying at least two of these!

PRODUCT TYPE: Stereo compressor with sidechaining.
TARGET MARKET: Bargain-hunting recording musicians who want a quality stereo compressor in the prosumer price range.
STRENGTHS: Great sound. Huge bang-for-buck ratio. Expanded feature set offers more options than similar, better-known units.
LIMITATIONS: Nothing significant.