Detail 01
Line driver, not a DI
It is built for line-level sources like keyboards and playback decks, not high-impedance instrument pickups.
Product detailSKU #1274228072036
Radial EngineeringJ+4 Stereo Line Driver -10dB to +4dB Interface
1/5
Independent shopping perspective
The Korena take
Stereo line driver that converts unbalanced -10dB consumer signals to balanced +4dB pro level. For connecting keyboards, laptops or DJ gear to a live console.
Strong match
Who this is for
- Feeding a mixer or snake from an unbalanced stereo keyboard output
- Sending laptop or playback audio to a console over long cable runs
- Stereo sources that need balanced XLR outputs to reach front of house
Consider the trade-offs
When to look elsewhere
- Guitar or bass DI duty, where a passive box handles the instrument level better
- Mono-only sources, where you pay for a channel you never use
- Anyone whose gear already has balanced +4dB outputs
What matters in use
The specifications, translated
Catalog numbers tell only part of the story. These are the details most likely to change how this product feels, sounds, or fits into a setup.
Detail 02
-10dB to +4dB conversion
Raises consumer-level output to professional level, so the console gets a strong signal instead of a weak, noisy one.
Detail 03
Balanced output
Balanced lines reject hum and interference, so long cable runs to a stage box stay quiet.
Detail 04
Stereo, two channels
Handles a left and right pair in one box, so a keyboard or laptop reaches the desk without a second unit.
Detail 05
Active design
Active circuitry needs power, unlike a passive box, but delivers the level gain a passive transformer cannot.
Final check
Know before you order
- 01Confirm your source is line level, not an instrument pickup or a microphone
- 02Requires power; verify the supply arrangement before a show
- 03You still need XLR cables to reach the console
Product questions
Before you decide
Straight answers to the questions shoppers most often ask about this product.
01Can I plug my guitar into this?
No. This is a line driver for line-level sources like keyboards, laptops and playback gear. A guitar or bass needs a direct box built for instrument-level, high-impedance pickups.
02What does -10dB to +4dB actually mean?
Consumer gear outputs a weaker signal (-10dB) than professional gear expects (+4dB). This raises the level so a mixer sees a proper signal instead of one you have to crank.
03Do I need one or two for a stereo keyboard?
One. This is a stereo unit, so it handles both the left and right channels of a keyboard or laptop in a single box.
04Will this fix hum in my long cable runs?
It gives you balanced outputs, which reject noise picked up along a cable run. That is the main defense against hum on long runs to front of house.
