Radial J+4 Stereo Line Driver Interface

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.

Radial J+4 Features

• 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

• J+4 Stereo Line Driver Interface1
• Three Year Warranty (transferable)1

• Audio circuit type Active -10dB ~ +4dB line converter, transformer isolated
• Number of channels 2
• Frequency response 20Hz ~ 20KHz (± 2dB)
• Dynamic range 102dB
• 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
• Maximum Input +17dBu @ 1kHz, 1% THD+N
• Maximum Output +15dBu @ 1kHz, 1% THD+N
• Ground lift, HPF, Level Control
  • Input Connectors: 1/4", RCA, 3.5mm
  • Output Connectors: XLR
• Construction 14-gauge steel
• Size (LxWxD) 3.3x 5x2" (84x127x48mm)
• Weight 1.55 lbs (0.7 kg)
• Shipping size (LxWxD) 4x3x6.5" (102x76x165mm)
• Shipping weight 1.92 lbs (0.87 kg)
• Power +15VDC/400mA adapter Included
• Conditions For use in dry locations only between 5°C and 40°C