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Radial J+4 2-Channel Signal Driver with Level Matching from -10dB to +4dB


Radial J+4 2-Channel Signal Driver with Level Matching from -10dB to +4dB


Manufacturer's Description

Balanced -10dB to +4dB Signal Driver

The J+4™ is a stereo interface designed to accept unbalanced low output devices such as instruments, computers or mobile devices and boost their signal to a balanced +4dB level for connection to professional audio recording and playback equipment.

Boost & balance any stereo signal

The J+4 allows you to boost nearly any stereo signal up to a +4dB balanced line level output, which can be sent over long distances without signal loss and connected directly to pro audio equipment such as mixers or recording interfaces. Multiple input connectors are available for integration with a variety of devices, including a stacked set of ¼" jacks for DJ mixers or keyboards, RCAs for CD players and a mini 3.5mm jack for smartphones and tablets. The J+4 delivers exceptional sonic performance, and is able to provide clean gain and eliminate noise by combining the advantages of active signal buffering with transformer isolation.


  • Stereo preamp boost signals to +4dB balanced line level
  • Increases gain for low output instruments & music players
  • Transformer isolated to eliminate noise caused by ground loops
  • Multiple input connector options to interface with any device


  • 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 (L x W x D): 84 x 127 x 48mm (3.3" x 5.0" x 2")
  • Weight: 0.70 kg (1.55 lbs)
  • Power: +15VDC/400mA adapter Included
  • Conditions: For use in dry locations only between 5°C and 40°C
  • Warranty: Radial 3-year, transferable