Classic 500 Series peak detecting "feedback" compressor/limiter with variable threshold and output levels
Originally released in the 70's, the API 525 is a "feedback" type compressor. 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, so the user can alter dynamics "on the fly" without level changes. A compression/limit switch sets ratio at either 2:1 or 20:1. Attack time is as fast as 15u/s. Four auto release modes are offered via two switches, 0.1s, 0.5s, 1.5s, & 2.0s. A De-Ess function inserts an inverse vocal energy curve filter in the detector for effective sibilance/pop reduction. The 525 design has been taken from the original blue prints and spec control drawings from the API archives.
Release times vary with frequency, with high frequency / full bandwidth content released faster than lower frequencies for natural envelope tracking. Attack time is fixed, chosen to catch the fastest peaks, without "pumping". Equally useful as a tracking, mixdown or program compressor/limiter, the 525 utilizes "vintage" dynamics control and an easy to use multi-function control set. The 525 has a hard-wire bypass switch, a balanced input, and a pinout that is the same as all the other 500 series modules. Two or more 525s can be linked for multi-channel compression.
The API 525 Compressor makes use of the 2510 and 2520 op-amps and exhibits the reliability, long life, and uniformity which are characteristic of all API products.
Caractéristiques
Exact reissue of API's original 525 from the early 70's
Peak detecting "feedback" compressor/limiter
Variable Threshold and Output levels
Unique "Ceiling" control combines key functions
Analog VU meter for monitoring gain reduction
4 Switchable release modes
De-Ess function
Traditional API fully discrete circuit design
Active Balanced Input/Output
Hardwire bypass
Spécifications
Input Impedance: > 30 K Ohms, Balanced Output Impedance: 100 Ohms, Transformer coupled, Balanced Operating Levels: -15 dBu to +20 dBu Maximum Gain Reduction: 25 dB Noise: 98 dB below +10 dBu output, at 10 dB of Compression Harmonic Distortion: 0.5% Max, 30 to 20 kHz Attack Time: 15 micro seconds Release Times: .1, .5, 2.0, 2.5 seconds De-essing: Inversion of the Voice Energy Curve Slopes: Compression, 2:1, Limit, 20:1 Metering: Compression or Limiting-Illuminated Analog dB meter, shows Gain Reduction Frequency Response: ±.5 dB, 30 to 20 kHz Power Requirements: ±12/18 Volts/DC, @80 ma. Size: 1.5" X 5.25" X 7.5" Deep Size (Boxed for Shipping): 4.5" X 6.5" X 10" Actual Weight: 1.77 lbs. Shipping Weight: 2.17 lbs