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Radial J-4 Active Stereo Line Driver

Radial J-4 Active Stereo Line Driver
Radial J-4 Active Stereo Line Driver
Radial J-4 Active Stereo Line Driver
Radial J-4 Active Stereo Line Driver
Radial J-4 Active Stereo Line Driver
Radial J-4 Active Stereo Line Driver

Radial J-4 Active Stereo Line Driver

Item #110837
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USD$229.99 Request Price Match
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Radial J-4 Active Stereo Line Driver

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.

J+4 Applications

Using the J+4 to boost a stereo signal
Increasing the output from a CD player to a +4dB balanced signal is easy. Just plug into the RCA inputs, adjust the volume level and the J+4 does all the work. Transformer isolation eliminates ground loops for quiet performance every time.

Using the J+4 with your computer
Today, computers and laptops are being used in all types of audio-visual systems. The J+4 makes it easy to interface with a built-in 3.5mm (1/8") TRS jack. Plug in and the J+4 will boost and balance the signal and deliver a professional line level signal.

Using the J+4 with a keyboard
Many keyboards and synthesizers do not have enough output to effectively drive the line level input on a mixer. This is particularly troublesome on older keyboards such as a Rhodes piano. The J+4 makes it easy with built-in ¼" inputs and balanced XLR outs.


  • 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
  • TRS Inputs
    Unbalanced inputs for instruments and -10dB consumer level devices
  • Output Level
    Variable level control used to set the output from the J+4.
  • 3.5mm Input
    Lets you easily interface your computer or iPod to the J+4 so that it can feed a PA system.
  • RCA Inputs
    Designed to connect -10dB unbalanced consumer level sources and boost their signal.
  • XLR Outputs
    Balanced +4dB professional line level outputs designed to feed a mixer or tape recorder.
  • Filter
    High pass filter helps eliminate low frequency rumble and resonance that often muddies up the sound.
  • Ground Lift
    Disconnects pin-1 ground at the XLR outputs to help eliminate hum and buzz caused by ground loops..
  • Warranty: Radial 3-year, transferable


  • 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
  • Features
    • Ground lift, HPF, Level Control
    • Input Connectors: 1/4", RCA, 3.5mm
    • Output Connectors: XLR
  • General
    • 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)
    • Shipping size (L x W 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 5°C and 40°C
… [ More ]
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