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525 Discrete Compressor

API Audio 525 Discrete Compressor
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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.


assemble a channel strip for 500 series !!

i would some advice to put together a channel strip for the 500 series... i need it to be the most versatile possible. my actual idea is based on: PRE: shadow hills mono gama EQ: great river harrison 32eq COMP : api 525 please feel free to give your suggestion !

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Lindell Audio 50 Series - (API®) Console emulation of the classic “American Sound”

...simplicity, and ease of use of the original 500 series since it is modeled after the acclaimed API® 525 compressor. Clearly, then, the Lindell Audio 50 Series far from falls short of the mark, with a fanciful feature set well worth highlighting here: 72 different TMT channel emulations in one plugin — just like a...

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Comparing my $19k pultec’s to plugins

...I haven't looked back since. I did the same thing a few years before with a Blue stripe 1176, an API 525, and an API 550A.

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