A versatile, business card-sized passive direct injection (DI) box PCB engineered for connecting high-impedance instruments (guitars, basses, keys) directly to low-impedance mic preamps and mixing consoles.

Technical Specifications

• Circuit Type: Passive transformer-isolated direct injection

• Form Factor: Compact "business card" footprint (85 mm x 55 mm)

• Feature Controls: Ground lift, signal pad, polarity reversal, and stereo-to-mono merge function

Key Features

• Comprehensive Tone & Signal Utility: Fully equipped with an input pad, polarity invert switch, ground lift for breaking ground loops, and a merge feature to combine dual inputs into a single DI output

• Clean Transformer Isolation: Completely passive operation eliminates hum and noise while requiring zero batteries or phantom power

• Versatile Audio Transformer Compatibility: Features a flexible PCB layout supporting multiple transformer models to match your desired output level and frequency response:

  • Jensen JT-DB-EPC

  • Cinemag CM-DBX

  • Lundahl LL1935

  • Pikatron ÜP3096M

  • Palmer PMT02 (supported on the black PCB version)

  • OEP A187A10C (supported on REV#2 of the green PCB version)

Important Assembly Notes

• Pin 1 Orientation: Double-check the direction of Pin 1 for your specific transformer before soldering

• Clearance: Leave a slight gap between the transformer base and the PCB to prevent short-circuiting adjacent pads

• Build Order: Mount and solder the transformer as the final step right before installing the populated PCB into the chassis

• 3D-Printable Enclosure Compatible: Matches Link Audio's free downloadable STL case files on Printables for easy, custom 3D printing

Included

• 1x P96D2 Passive DI Box Bare PCB

Product name: P96D2 Product identifier:  PCBX002 Manufacturer: Link Audio Design, August-Bebel-Str.18, 08373 Remse, linkaudiodesign@gmail.com