The 525 is a feedback type compressor originally released in the 70’s. An input (threshold) control and output (make-up gain) control are provided, along with an additional “Ceiling” fine-tune function which can increase gain reduction (lower threshold) while simultaneously raising output level to match for on-the-fly adjustments without level changes. A compression/limit switch sets ratio at either 2:1 or 20:1 and its Attack time is fixed and as fast as 15u/s. Four auto release modes are offered via two switches, 0.1s, 0.5s, 1.5s, & 2.0s.

The 525 features a hard-wire bypass switch, a balanced input, and a pinout that is the same as all the other 500 series modules and makes use of API’s signature 2510 and 2520 op-amp. Two or more 525s can be linked for multi-channel compression.

• Peak detecting “feedback” compressor/limiter

• Variable Threshold and Output levels

• Analog VU meter

• 4 Switchable release modes

• De-Ess function

• Active Balanced Input/Output

• Hardwire bypass