The Radial J48 Stereo is a professional two-channel active direct box designed for demanding stage and studio applications. Built around a proprietary low-noise analog circuit, the J48 Stereo delivers exceptional signal handling, low distortion, wide frequency response, and high headroom while maintaining clear stereo separation between its left and right channels.

A unique switching power supply raises the internal rail voltage to provide up to 9 Volts of signal handling, making the J48 Stereo particularly well suited to high-output keyboards, battery-powered instruments, and other sources that can overload conventional active direct boxes.

The J48 Stereo can function as two independent direct boxes, Its rugged 14-gauge steel construction, compact enclosure, polarity reverse, input pad, and high-pass filter provide the reliability and flexibility needed for professional recording environments.

Key Features

• Two-channel active direct box for stereo or dual-mono sources.
• Proprietary low-noise analog circuit with 109dB dynamic range.
• High-voltage switching supply provides up to 9V signal handling.
• Maintains stereo separation with low crosstalk between channels.
• Input pad, 180° polarity reverse, ground lift, and high-pass filter.
• Rugged 14-gauge steel chassis and outer shell.
• Powered by 48V phantom power.
• Compact design for stage, studio, and touring applications.

Ideal For

• Stereo keyboards and synthesizers.
• Digital and analog keyboards.
• Bass guitars and acoustic instruments.
• Dual-instrument setups.
• Professional live sound systems.
• Recording studios and broadcast applications.
• Stereo sources requiring high headroom and low distortion.

What's in the Box

• Radial J48 Stereo active direct box.
• Product documentation.

Inputs & Outputs

• Channels: 2.
• Input Connectors: 2 × 1/4-inch input and thru connections.
• Output Connectors: 2 × XLR.
• Input Impedance: 220kΩ via 1/4-inch input.
• Output Impedance: 600Ω via XLR output.
• Maximum Input: +10dBu.
• Power: 48V phantom power.
• Controls/Functions: Input pad, 180° polarity reverse, ground lift, and high-pass filter.

How the J48 Stereo Compares

The J48 Stereo combines two active DI channels, high-voltage signal handling, stereo separation, and rugged steel construction in a compact format. Its increased internal rail voltage is particularly suited to high-output instruments and stereo keyboards that can exceed the headroom available from conventional active direct boxes.

Frequently Asked Questions

Is the Radial J48 Stereo a stereo direct box?

Yes. The J48 Stereo features two independent active DI channels that can handle a stereo source such as a keyboard or two separate instruments.

What type of power does the J48 Stereo require?

The J48 Stereo operates on 48V phantom power supplied by the connected mixing console, audio interface, or other compatible equipment.

What is the dynamic range of the J48 Stereo?

The J48 Stereo provides 109dB of dynamic range, helping maintain clean and detailed audio with high-output instruments.

Can the J48 Stereo be used with two separate instruments?

Yes. Its two-channel design allows it to function as two independent direct boxes, making it suitable for dual-instrument setups such as two basses or other instruments.

Is the J48 Stereo suitable for high-output keyboards?

Yes. Its high-voltage switching supply provides increased headroom for high-output digital and analog keyboards, synthesizers, and other instruments that may overload conventional active DI boxes.

What are the dimensions of the J48 Stereo?

The J48 Stereo measures approximately 3.3 × 5.0 × 2 inches and weighs approximately 1.55 lbs, providing a compact solution for stage and studio setups.

Full Technical Specifications

Audio Performance

Audio Circuit Type	Proprietary analog circuit with low-noise op-amp
Number of Channels	2
Frequency Response	20Hz to 20kHz
Dynamic Range	109dB
Total Harmonic Distortion	0.002% @ -5dBu
Intermodulation Distortion	0.003% @ -3dBu
Phase Deviation	+10° at 20Hz / 0° at 1kHz / -1° at 20kHz
Equivalent Input Noise	-103dBu
Noise Floor	-99dB below 0dBu
Maximum Input	+10dBu

Input & Output

Input Impedance	220kΩ - 1/4" input
Output Impedance	600Ω - XLR output
Input Connectors	2 x 1/4" input and thru
Output Connectors	2 x XLR
Input Pad	Included
Polarity Reverse	180°
Ground Lift	Included
High-Pass Filter	Included

Power & Signal Handling

Power	48V phantom power
Power Supply Design	Proprietary digital switching
Maximum Internal Signal Handling	Up to 9V
Signal Type	Stereo or two independent instrument channels
Headroom Design	Higher-voltage internal rails for improved signal handling

Construction & General

Construction	14-gauge steel chassis and outer shell
Operating Conditions	Dry locations only
Operating Temperature	5°C to 40°C
Part Number	R800 3002 00

Physical Specifications

Product Dimensions (L x W x D)	3.3" x 5.0" x 2"
Product Weight	1.55 lbs