Heritage Audio 73 DI ONE

Active DI Box – Heritage Audio 73 DI ONE

The 73 DI ONE is a single-channel active DI box developed by Heritage Audio, based on the classic 73 topology. It features a discrete JFET input stage, transformer-balanced Class A output, and +48V phantom power, delivering a rich and dynamic direct signal for studio and live use.

Features

The 73 DI ONE uses the legendary 3-transistor 73 topology adapted for a DI box. The input stage is a J109 JFET with 2.2 MΩ impedance, providing high input impedance for instruments. Class A output with a 2N3055 transistor drives a custom Heritage Audio transformer. A -15 dB PAD helps with hot signals or speaker outputs. The THRU output allows parallel connection, and the ground lift eliminates hum. All jacks, including XLR, are gold-plated, and the enclosure is made of sturdy steel.

Specifications

• Type: Active DI box, single-channel
• Input: Hi-Z 1/4” (6.35 mm) unbalanced
• Thru: 1/4” parallel output
• PAD: -15 dB
• Output: XLR, balanced (Mic level, pin 2 hot)
• Power supply: +48 V phantom power
• Indicator: Red LED (power on)
• Chassis: 14-gauge steel, MIL-spec PCB