Api Audio 312 Mic Pre

A 1970s Classic at the Heart of API's DNA

Introduced in the 1970s, the API 312 is one of the brand's most sought-after mic preamps and, more broadly, a landmark in the history of modern recording. Designed from the original schematics attributed to API co-founder Saul Walker, it established itself as a reference for its ability to capture fast transients while maintaining a sense of weight and depth.

The 312 is also known as the cornerstone of the "312" spirit found in more recent products in the range, notably multi-channel rack units. The major innovation here is not a reinvention, but direct access to this historic signature in a 500 series module, easier to integrate, multiply, and configure according to your needs (one channel for vocals, multiple channels for drums, etc.).

What Recording Applications Is the API 312 Made For?

The API 312 targets studios and home studios seeking a mic preamp with character without sacrificing precision. Its personality is particularly suited to sources where impact and presence are desired: snare, toms, overheads, electric guitars, basses via amp mic, brass, percussion, and also vocals when a "forward" feel and natural articulation are wanted.

Thanks to its gain range and discrete design, it performs well in high-quality recording chains: dynamic and condenser microphones, analog processing in insert via your rack (depending on your chassis), or direct conversion to your audio interface. The 500 series format makes it an excellent choice if you want to build a custom rack (preamps, EQs, compressors) while maintaining sonic coherence.

Design and Features: The "312 Feel" in 500 Series

Discrete Stage, 2520 and Transformers: The API Signature

At the heart of the module is a fully discrete circuit design combined with the 2520 op-amp, an iconic element of the API sound. This topology is prized for its dynamic handling: fast response, clear attack definition, and a stable feel when pushing levels. The input relies on the patented AP2516 transformer, contributing to the analog texture and the way the preamp "holds" energetic sources.

Gain, Headroom, and Control: Ready for Tracking

With 69 dB maximum gain, the 312 covers a very wide range of uses, from delicate sources to very dynamic ones. To maintain control in all situations, you have a -20 dB attenuator pad: essential to avoid saturating the input with high-output microphones or very loud sources (snare, close brass, guitar amp close-miked).

The switchable 48V phantom power allows easy use of condenser microphones. For monitoring, the module includes a VU meter to visualize average levels and a peak LED to immediately spot peaks, very useful when seeking the right balance between level, headroom, and color.

What's Different Compared to Larger Formats

If you're familiar with the spirit of API rack units, this module emphasizes a simple idea: the same sonic philosophy in a 500 format, more flexible and scalable. This is a tangible advantage for building a modern hybrid setup: you can pair the 312 with your favorite processors, gradually multiply channels, and adapt your rack to sessions (vocals, live music, multitrack recording) without giving up the API character.

Technical specifications

Category

microphone preamp

Design

500 series module

Max Gain

69 dB