Originally offered in the early 1970s, API founder Saul Walker designed his first microphone preamp called the 312. This microphone preamp was used in his first API recording console; only the gain control knob was available on each channel strip/module. Now available as a 500 module, the new API 312 has the exact same circuit with a 2520 op-amp and both API 2516 input and API 2503 output transformers. This preamp design is also used in API’s 3124V, the 3124MV, and the A2D products.
The API 312 features a maximum of 69dB of microphone gain, a -20dB attenuator pad, and a 3:1 output transformer switch. Like the API 512c model, the 3:1 switch selects a different tap on the output transformer to lower the throughput gain by about 12dB.
You can see this gain change on the cute little vintage-style VU meter with its own peak LED. Being able to lower the output gain allows you to drive the preamp harder towards clip yet, still adjust a proper output level.
The API 312 sells for $795 MSRP and backed by API’s unique Five-Year Warranty.