312 mic preamp module building guide

312 is a microphone preamp based on a famous vintage american circuit. We've also included an active FET DI circuit for even greater flexibility of the module. RackNeve 312 module is an affordable and compact design that allows to pack up to four 312 preamps into 1 rack unit space.

We've included our version of the discrete op-amp with this preamp. This op-amp has the 2520-compatible footprint. There are several SMD transistors, so make sure you have a good soldering iron with a fine tip. Magnifying glass will be very helpful as well.

You can find all the steps below and in the menu at the left side of the page.

PLEASE NOTE: complete building Guide will be available after purchasing of 312 module PCB set.

Here is the rough estimate of costs of the 312 module:

Electronic parts and knobs (Mouser, US pricing) 106$
Audio transformers and attenuator 110$
Front panel, PCBs 40$
TOTAL (shipping not included): 256$

Approximate build time - 8 hours.

Complete 312 preamp Bill of Materials here.

GroupDIY support thread here.