From API Audio
525
Discrete Compressor, Re-Issue
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, 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. |
Manuals & documents
Free 3-Year Warranty
In addition to the standard included manufacturer warranty, virtually all new products carry our exclusive, industry-leading, absolutely free Sound Pure 3-Year Warranty, which includes parts and labor. It's our way of adding real value to the personal touch our small, dedicated team brings to every purchase.
Coverage exclusions live in Terms & Conditions, Section 27. Read the warranty →
Sound Pure Studios · Durham, NC
Come hear it in our control rooms.
Sound Pure is a working studio in Durham, NC — a 1,000 sq ft live room and two pro control rooms. Book a session to audition gear in a world-class acoustic space before you buy.