API: 525 Compressor
Features
- 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
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.
Specifications |
|
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, |
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. |