Radial Engineering J+4

The Radial J+4 is a -10dB to +4dB stereo preamp that lets you boost a low output unbalanced signal and interface it with a balanced professional audio system.

The Radial J+4 is a stereo interface designed to accept unbalanced low output level devices such as instruments, computers or CD players and boost the signal to a balanced +4dB level for easy manipulation in professional environments such as broadcast, recording studios and live touring.

The design begins with 100% discrete components for optimal signal transfer. Careful attention has been paid to eliminate noise by combining the advantages of active signal buffering with transformer isolation. The J+4 delivers better than 95dB signal to noise while ensuring hum and buzz caused by ground loops along with spurious noise from clocking does not pollute the signal path. For ease of use, controls have been kept to a minimum. This includes a stereo level control, a high pass (low cut) filter and ground lift. The choice of input connectors include a stacked set of ¼`` jacks for DJ mixers or keyboards, RCAs for CD players and a mini 3.5mm for iPods.

As with all Radial products, the Radial J+4 is built tough to handle the extreme rigors of professional touring. A unique 14-gauge steel I-beam inner frame ensures the sensitive PC board will not be subjected to outside stress which could potentially cause solder joints to fail. An innovative book-end outer shell creates protective zones around the controls, switches and connectors to further improve dependability while a full bottom no-slip pad provides both mechanical and electrical isolation.

The Radial J+4 balanced line driver delivers exceptional sonic performance, plenty of headroom and ultra low noise making it the ideal companion for today's more demanding professional audio systems.

• Stereo preamp boosts signals to +4dB balanced line level

• Increases gain for low output instruments & music players

• Transformer isolated to eliminate noise caused by ground loops

• Plenty of connector options - Plug and play easy to use

• Audio circuit type : Active -10dB ~ +4dB line converter, transformer isolated

• Number of channels : Stereo

• Frequency response : 20Hz ~ 20KHz (± 2dB)

• Dynamic range : 102dB

• Maximum input : +17dBu @ 1kHz, 1% THD+N

• Total harmonic distortion : 0.004% @ 1kHz, +10dBu output

• Phase deviation : 0.5 @ 100Hz; 4 @ 20Hz

• Input impedance : 10k Ohms, unbalanced

• Output impedance : 1.6k Ohms, balanced

Features

• J+4 transformer : Radial custom transformer

• High pass filter : -3dB @ 100Hz (12dB.Oct.)

• Ground lift : Disconnects XLR pin-1 at isolated output

• XLR configuration : AES standard (pin-2 hot)

• Connectors : ¼", RCA, 3.5mm inputs; XLR-F outputs

General

• Construction : 14 gauge steel chassis & outer shell

• Finish : Durable powder coat

• Size : (W x H x D) 84 x 127 x 48mm (3.3" x 5.0" x 2")

• Weight : 0.70 kg (1.55 lbs)

• Shipping size: W x H x D : 102 x 76 x 165mm (4" x 3" x 6.5")

• Shipping weight : .87 kg (1.92 lbs)

• Power : +15VDC/400mA adapter Included

• Conditions : For use in dry locations only between 5C and 40C