User Manual

Radial Engineering Ltd. J48 Stereo™ User Guide

USING THE -15dB PAD

Inside the J48 Stereo is a unique switching power supply that is

designed to provide plenty of headroom even when pushed very

hard. There are however, instances when the output from an in-

strument can be extreme. To prevent distortion, the J48 Stereo

has a -15dB input pad that reduces the input sensitivity. Examples

could be a very high output digital piano, active bass guitar or

maybe the overly aggressive output from a DJ mixer. If you hear

distortion, simply depress the PAD.

USING THE GROUND LIFT

An active direct box is in essence a unity gain amplier that re-

quires power to work. In the early days, active direct boxes typi-

cally employed a battery for power. Today, phantom power from

the console has become the most common power source. This

48 volt supply uses the pin-1 (ground) and pin-2 (hot) on the XLR

cable to provide DC power to the direct box while audio is sent in

the opposite direction over the same cable.