API : AUDIO THE CHANNEL STRIP API

 

The result of thoughtful engineering, The Channel Strip includes everything needed to record an audio signal. It all starts with the famed 512c Mic Preamplifier, which includes the benefit of additional Mic, Line or Instrument input switching. Next is the 527 multi-mode Compressor with fully adjustable Threshold, Attack, Release, and Ratio controls on detented pots. The patented THRUST® circuit in the 527 gives your track the "in-your-face" punch that has made this circuit an award winner. Also included in The Channel Strip is probably the most recognized and revered API EQ of all time, the 550A three-band Equalizer with its switchable frequencies and 12dB of boost or cut. The 550A's High and Low frequency bands can be individually switched to be shelving EQs, and the "B.P. Filter" switch inserts a 50Hz to 15KHz bandpass filter.

 

At the output of the unit is the 325 Line Driver, taken directly from API console designs with an output level pot and 10 segment meter. The meter can also be switched to show the output level of the preamp. Each of The Channel Strip's processing pieces can be switched in or bypassed individually, while a flip switch internally routes the compressor after the EQ if desired. Additional features include a sidechain input and the famous API 2520/transformer combination.

 

Features

 

API 512c Mic Preamplifier

The Channel Strip's 512c Preamplifier section is brimming with classic API sonic character, supplying you with a line preamp at unity gain, an instrument preamp with 50dB of gain, and a mic preamp with 68dB of gain. You get a -6dB line pad, a -20dB microphone pad, switchable +48V phantom power, and a polarity inverter. A +27dBu preamp output peak indicator and LED VU meter add even more utility to this world-class preamp. The engineers here at Sweetwater are blown away by the authenticity of The Channel Strip's 512c Preamplifier section — its 2510 and 2520 op-amps are the real API deal.

 

API 527 Compressor

API's The Channel Strip's multimode 527 Compressor section includes fully adjustable Threshold, Attack, Release, and Ratio controls, with selectable feed-forward/feedback and hard-/soft-knee compression. API's patented Thrust feature is on hand, providing ear-grabbing frequency-dependent sidechain control. You also get a 10-segment gain-reduction meter, a sidechain input, a Link switch for multiple-unit, interdependent compression linking, and a Comp Bypass switch with hard-relay switching. Finally, you get a switch to internally route the compressor post-EQ. And, like the rest of The Channel Strip's sections, the 527 Compressor boasts 2510 and 2520 discrete op-amps.

 

API 550A Equalizer

The API 550A Equalizer is a true classic — an EQ embraced since the late '60s and a standard by which countless EQs continue to be judged. The Channel Strip includes this fabled EQ, supplying you with three bands of classic API equalization. Each band includes seven API-selected frequency centers, with a maximum of 12dB of boost/cut per band. You get reciprocal and repeatable filtering, the section's Low and High EQ bands offer shelf/peak switching, and you get a bandpass filter. And, of course, the API 550A Equalizer gives you access to API's ultra-musical Proportional Q, which narrows the filters' Q at extreme settings. The Channel Strip's EQ section vaunts a traditional, fully discrete API circuit design with 2520 discrete op-amps.

 

API 325 Line Driver

At the end of API's The Channel Strip, you'll find a 325 Line Driver, culled from classic API console designs. This section includes a switchable insert return, a remote-controllable soft mute function, and full attenuation to +10dB of gain. You get a high-headroom, +30dB clip level, with an output level pot and a 10-segment LED VU meter that can be switched to display the output level of The Channel Strip's 512c Mic Preamplifier. A 2520 discrete op-amp and a transformer-coupled output complete the 325 Line Driver section.