J48 J-Class Phantom Powered (48V) DI Box

The J48 is a high performance active direct box for live concert touring and professional recording studio applications, with the ability to handle extreme transients without distortion while delivering the natural sound of your instrument.

The Radial J48™ direct box is the world’s finest phantom-powered active DI. It has been optimized to handle extreme transients using only the 5 milliamps of available current from typical 48-Volt phantom-power. The J48 features a unique digital switch-mode power supply that steps up the internal rail voltage to an amazing 9-Volts.

Most battery-powered guitars and basses are active and will produce as much as 7-Volts when played at maximum volume. Since typical direct boxes are only able to handle about 3 volts, they choke. The trouble is caused when the input signal is greater than the internal rail voltage. This creates all types of distortion: bass sounds thin and lacks punch, guitars sound scratchy and tend to have sporadic peaks, and they lose their natural body resonance.

Because the J48 has more ‘horse-power” (current to work with), it is able to handle these transients without choking. This extra headroom significantly reduces harmonic, phase and inter-modulation distortion. And when you fix all of the problems, a funny thing occurs... you get great sound!

The Radial J48 has been designed from the ground up to deliver the most natural tone. As a direct box manufacturer, Radial do not believe it is their task to alter the sound of your prized '1962 Fender Jazz Bass', but retain and transfer the true character of the instrument to the mixing console without adding distortion or introducing artifact. This design philosophy has gained a tremendous following from many of the world's most demanding musicians.

Using only 48V phantom power, the Radial J48 is an active direct box that produces an exceptionally linear response that extends from 20Hz up to well above 40kHz. Low distortion of all types is achieved via a unique digital switching power supply that raises the internal operating rail voltage for added headroom and improved signal handling. The results are truly amazing. The J48 delivers an ideal even-order harmonic cascade and a sonic performance that outperforms DIs costing several hundreds more.

And like all Radial products, the J48 is both feature-rich for studio and made tough to handle the road. This includes a -15dB input pad to tame extra loud signals, 180° polarity reverse for feedback control on stage and a ground lift to help reduce hum & buzz caused by ground loops. Special features include a merge function that elegantly mixes left-right signals to mono without phase cancellation. To minimize resonant feedback with acoustic instruments, the J48 is also equipped with an 80Hz high-pass filter (low-cut). When engaged, this also increases headroom by eliminating unneeded bass frequencies.

Radial's innovative book-end design protects switches and connectors from abuse while the internal I-beam construction eliminates stress on the PC board. This serves to reduce solder joints from going 'cold' and delivers trouble-free performance for years. A full-bottom no-slip pad provides mechanical and electrical isolation while providing plenty of 'stay-put' for rockin' stages!

The Radial J48 is used by artists as diverse as acoustic guitarist Tommy Emmanuel; super-star engineer Joe Chiccarelli; and one of the most successful bands of all time, Fleetwood Mac.

DI Boxes

Radial JDI Passive DI Box

Radial J48 Phantom Powered Pro DI Box