Heritage Audio have been lovers of the 73-style topology since the very beginning. After years of consideration, they've managed to adopt the legendary 3-transistor topology to provide a top-notch DI at a reasonable price. The first transistor in the 73 stage was substituted by a J109 JFET, yielding a 2.2-megohm input impedance instead of the 47 kilohms in the original circuit.

A clever design on the power supply section allows it to keep the metal can 2n3055 output transistor that directly drives the custom-developed silicon steel grain-oriented output transformer, which is a phantom power-friendly version of the venerable LO1166, custom built to enhance the natural performance of your instrument in the same, unique way that a vintage 73 preamp will enhance a mic signal.

Usually active DI boxes work best with passive circuitry instruments like guitars and basses but thanks to the 73 DI’s high-input headroom, it can also be used wonderfully on keyboards, synths, drum machines, and samplers when plugging directly into a PA or recording system is required. Passive basses such as precision and jazz bass suddenly acquire a new life, with a sparkling high end, a solid bottom end, and that low midrange saturation the 73 is famous for.

Instruments like the Fender Rhodes produce their full body and bell-like tone like never heard before. Saturation makes Wurlitzer electric pianos growl like they’re being amped without the hassle. The possibilities are endless.