Classic API Compression for Your 500 Series Rack
The API 527A will infuse your projects with the same unmistakable sound that launched a thousand hit records. The 527A takes API's popular 500 Series compressor/limiter module and elevates it with an overhauled 10-segment gain reduction meter and a bypass switch with a soft bypass option for adding color to a signal without compression. This module teems with signature API sound, courtesy of 2510 and 2520 discrete op-amps, and it includes 31-position detented controls for easy repeatability. The 527A offers both feed-forward and feedback compression, hard- and soft-knee compression, and API's patented Thrust function for frequency-dependent sidechain control. You can also link two 527A modules together for effortless stereo operation.

API's patented Thrust function
When you choose API, you know you're getting amazing sonic character. And with the 527A, you've got a wide range of characters to choose among and dial in. To start, the 527A has API's patented Thrust highpass filter before its RMS detector, which gives you frequency-dependent sidechain control for punchy low end.

The best of the old and new
There are two types of compression onboard the API 527A: "old" and "new." The old style uses the feedback type of compression found on the classic early-'70s 525; the new style uses a feed-forward type like that of many popular modern compressors.

Flexible bypass options
527A's flexible bypass options make it useful in a myriad of situations. You can remove this 500 Series module from your signal path altogether, which saves you time in the studio — no need to physically un-patch the device. Beyond that, you can use the 527A's soft bypass function to impart its analog flavor to your signal without compressing it, much like the 529 bus compressor.