Radial Engineering J48 Data Sheet

J 4 8™ A C T I V E D I R E C T B O X

Order No. R800 3001

The Radial J48 direct box is the world’s fi nest phantom-powered active DI. It has been optimized to
handle extreme transients using only the 5 milliamps of available current from typical 48-Volt phantom­power. The J48 features a unique digital switch-mode power supply that steps up the internal rail
voltage to an amazing 9-Volts.

Most battery-powered guitars and basses are active and will produce as much as 7-Volts when played
at maximum volume. Since typical direct boxes are only able to handle about 3 volts, they choke. The
trouble is caused when the input signal is greater than the internal rail voltage. This creates all types of
distortion: bass sounds thin and lacks punch, guitars sound scratchy and tend to have sporadic peaks,
and they lose their natural body resonance.

Because the J48 has more ‘horse-power” (current to work with), it is able to handle these transients
without choking. This extra headroom signifi cantly reduces harmonic, phase and inter-modulation
distortion. And when you fi x all of the problems, a funny thing occurs... you get great sound!

Features

• Superior dynamic headroom

• High input impedance reduces loading

• Merge switch sums stereo instruments to mono

• Low-cut fi lter, -15 dB PAD, and polarity reverse

Applications

• Provides extra ‘reach’ and ‘air’ in your sound!

• Ideal for active acoustic guitars and basses

• Great for keyboards and drum modules

• Equally wonderful for live or studio

Cool stuff

• Huge 9-Volt internal rail voltage for extra headroom

• Handles loud transients without choking or clipping

• No batteries required, works with phantom-power

• 3 year transferable warranty

Headroom - J48 gives you more!

3-Volts
Typical active DI

Typical headroom
of most DI’s is a
mere 3 Volts. This
was originally de­signed for passive
guitars.

3V 7V 9V

Rail voltage

7-Volts
Active guitar/bass

The output from
today’s active guitars
& basses reaches 7­Volts, causing most
DI’s to square wave.
This makes them
sound harsh.

Peak

Square
wave

9-Volts
J48 max rail voltage

The J48’s 9-Volt
rails provide the
extra headroom so
it won’t choke! More
headroom means you
get less distortion and
better sound!

J48 Rail
voltage

J48

Extra

Headroom

R a d i a l S m a r t S h e e t

-15dB PAD allows super-hot inputs
such as from a CD player to be con­nected and balanced for long runs.

MOMENTARY LED will fl ash once to
tell you phantom-power is present.
This saves power for the audio circuit.

MERGE FUNCTION turns the input
and thru jacks into a passive mixer
to sum stereo signals to mono. This
saves valuable inputs on the mixer!

INPUT connects from instrument,
the THRU to the amplifi er. High
input impedance reduces loading.

XLR OUT 600 Ohm balanced,
mic-level output will drive 1000 feet
without appreciable noise.

POLARITY REVERSE fl ips the
polarity from the AES standard pin-2
to pin-3 on the XLR.

80HZ LOW-CUT (high-pass) fi lter
gently reduces excessive bass for
more headroom and clarity. Elimi­nates run-away resonant feedback
from acoustics!

GROUND-LIFT disconnects the
internal ground path between the
input and the output.

HEAVY-DUTY WELDED I-BEAM
enclosure of 14 gauge steel makes
it impossible to torque the PC board.
Eliminates cold solder joints.

HIGH CYCLE heavy-duty switches
are rated at 10,000 cycles.

MILITARY-GRADE PCB with full
surface ground plane to reduce
susceptibility to RF noise.

DIGITAL SWITCHING PSU steps
up the internal rail voltage to 9-Volts.
The J48 will not choke like other DI’s
when hit with loud transients.

BAKED ENAMEL fi nish for excel­lent durability and great looks for
years!

R a d i a l E n g i n e e r i n g L t d . · T el: 604-942-1001 · Fax: [phone] · www. r ad i a l e n g . c o m · e m a i l i n f o @ r a d i a l e n g . c o m

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