Descripción
A DESIGN THAT HAS BEEN 15 YEARS IN THE MAKING AND MORE THAN 50 YEARS OF
HERITAGE
It’s no secret that we are lovers of the 73 topology since the very beginning of Heritage Audio,
especially the 3055-driven transformer coupled Class A output stage which is the trademark of
that sound. After years of consideration, we’ve managed to adopt the legendary 3-transistor
topology circuit to serve as the best DI you could ever get, at any price range.
This wasn’t an easy task, as a very high input impedance was needed and phantom power was
a must. The first transistor in the 73 stage was substituted by a J109 JFET, yielding a 2.2
megohm input impedance instead of the 47 Kohms in the original circuit. This transistor is the
same one that is used (and loved) in the tens of thousands of the preamp DIs that Heritage
Audio has included in all of its products over the last decade and a half turning it into an industry
standard.
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. The results need to be heard to be believed.
Being a transformer based unit, its output is isolated from the instrument and there is a further
provision for lifting the ground, as well. An additional 15dB PAD switch helps with hotter
instruments and even allows speaker outputs to be plugged into the 73DI ONE and 73DI 2. A
THRU parallel connection rounds out the pack, and all jacks and XLR are gold plated and
isolated from chassis.
BRING OUT THE TRUE TONE OF ALL YOUR INSTRUMENTS
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 them directly into a PA or recording system
is required. Passive basses such as P-Bass and Jazz Bass suddenly acquire a new life, with a
sparking 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 EPs growl like they’re being amped without the hassle. The
list goes on and on.
AND ENHANCE YOUR SIGNAL WITH JUST THE RIGHT TOUCH OF VINTAGE WARMTH
AND VIBE
This meticulously engineered design is what gives the 73 DI its outstanding performance,
delivering a rich, dynamic direct sound that fully captures the harmonic complexity of any
instrument and even pre-recorded tracks.
An attractive yet protective extruded aluminium case makes the 73 DI virtually indestructible and
totally roadworthy, with all connections recessed for idiot-proof operation. Available in single and
dual channel configurations with a pending 8-channel version.
BULLET POINTS 73 DI 2
• Dual channel active DI box
• Class A, JFET discrete input stage as seen on all Heritage Audio top of the line products
• Low impedance custom Heritage Audio designed 73-DI output transformers
• Outstanding signal integrity and superior noise rejection
• Rugged 14-gauge steel enclosure prevents PCB stress and potential component failure
• MIL-spec circuit board with full ground plane for ultra-quiet operation
• Durable metal switches rated for over 25,000 cycles
• 15dB pad
• Ground lift switch
• Input / Thru gold-plated jacks
• Gold-plated XLR output
• Operated by standard +48V phantom power with red LED indicator light
