Chameleon Labs 7721 Stereo VCA Compressor  From Chameleon

When designing the 7721, Chameleon’s engineers started with a clean sheet of paper and deeply evaluated the details associated with developing a bus compressor for the modern studio. Basing detection and voltage control on a voltage control amplifier (VCA) topology and designing a circuit that provides low noise and transparency the team created an acoustic “glue" that is capable of consistently delivering punch and loudness to the signal.

The 7721 provides a classic set of adjustable settings as well as controls only available on esoteric compressors, including:

- Soft Knee / Hard Knee – Allows you to change between a softer arriving compression effect and a faster arriving, limiting type effect.

- Peak / RMS – This control allows you to choose between the Peak and RMS detection schemes that are quite different. Peak detection engages the compressor by monitoring peak or instantaneous voltage signals. RMS engages by looking at the average energy in the signal and comparing it to the threshold setting. Very different modes of operation that provide great solutions for specific problems.

- High Pass Filter – Allows you to filter out low frequencies and avoid pumping effects. This is particularly helpful when using the sidechain to more precisely control which frequencies are being compressed.

- Classic Controls – Threshold / Attack / Release / Ratio – Low ratios provide a nice starting place for master transparency, 4:1 provides more color and higher ratios for a tougher sound full of character. We like to use Attack and Release controls to respond to tempo and feel of a track.

- Blend – This control allows you to blend, or mix, the original uncompressed signal with the compressed signal providing another tool you can use to obtain your desired objective.

- VU Meter - Monitor Input, Outputs and Gain Reduction levels.