API Issues Limited-Edition 50th Anniversary 312 and 550A Modules

API was first formed in 1969, soon after co-founder Saul Walker turned the electronics skills he'd developed in the U.S. Navy to audio engineering.

Upon founding API, he created the first 500 Series modular console, whose influence continues to be seen in the wide array of such modules available from brands across the recording industry.


The 550A EQ, one of his most famous innovations, was first released in 1971.

The API 550A 50th Anniversary Edition, like its predecessors, is a discrete, 3-band EQ. While versions of the 550A have been in near-continuous production since its introduction, this anniversary model uses the original early '70s specs.

Hand-built and hand-wired, there will only be 50 units available, for a price of $2,000.

The features, according to API, include:

  • Hand-wired Limited Edition model with 50th Anniversary Faceplate
  • Reproduction of the legendary 1971 550A
  • 3 bands of classic API equalization
  • 5 selectable frequency centers on each band
  • High and Low bands offer shelf/peak switching
  • "Proportional Q" narrows filter Q at extremes
  • Switchable band pass filter
  • Individually Serialized (1-50)

Walker's 312 originally served as the mic input amp for all of the early API consoles in the 1970s. While Brent Averill and other engineers would later repurpose original 312 cards or recreate them in rack enclosures, this 50th anniversary model marks the first time that API has placed the 312 in a 500 Series module.

Original circuits are still prized today, while BAE, Warm Audio, and other firms continue to base new models off of the design. API too has used the circuit as the basis for the company's popular 3124 four-channel preamp.

The API 312 50th Anniversary Edition retains the same circuit as the original 312, but packages it into a modern 500 Series module.

It includes a vintage-style analog VU meter as well as API's 2516 Input Transformer. Only 150 anniversary 312 modules will be built, available for $1,500.

The main features, according to API, are:

  • API's Classic 312 Microphone Preamp in a 500 Series module
  • Reproduction of the Original 312 PCB Design
  • Mic Preamp with 65 dB of gain
  • Proprietary AP2516 Input Transformer
  • 20 dB pad switch
  • Switchable 48V phantom power
  • Vintage Style Analog VU Meter
  • Peak LED
  • Limited Production with 50th Anniversary Faceplate
  • Individually Serialized (1-150)

Check back soon for availability. For all the latest news and product releases from the NAMM 2019 convention, check out our ongoing coverage.

See more New Products and Highlights from Winter NAMM 2019
comments powered by Disqus