Radial Engineering R8001105 PRO48, Phantom Powered Active DI

Exceptional sonic performance
The Pro48's innovative internal switching power supply significantly increases headroom producing less distortion while yielding a smooth, linear response that extends from 20Hz to well above 40kHz. This results in natural, uncolored signal that is as good or better than DI boxes costing several times more. The superior performance makes the Pro48 an ideal candidate for use with battery powered active basses and acoustic guitars that tend to overload other direct boxes.

Using the Pro48 with acoustic guitar
The Pro48 is the perfect interface for acoustic guitar on stage. The high internal rail voltage is able to handle the dynamics of today's active instruments without choking and deliver the smooth, natural sound of the instrument.
Using the Pro48 with bass
Whether you use an active or passive bass, the Pro48's exceptional signal handling is able to capture the sound of the instrument without distortion or adding artifact. And with proper loading, your bass will sound round and smooth when you record or play live.
Using the Pro48 with acoustic instruments
With more headroom and less distortion the Radial Pro48 is a great all-round active direct box for instruments of all types. This makes it particularly effective with instruments that can sound 'peaky' or 'edgy' when amplified.

• High performance active direct box
• Increased dynamic range and headroom
• 48V phantom powered with switching supply
• Ideal for acoustic guitar and bass

What is the difference between the Radial Pro48 and J48™?
The Pro48 is a pared down version of the J48 that features the same audio signal path but with less features. Gone are the low-cut filter, 180º polarity reverse and the stereo to mono merge functions. We have however kept the -15dB pad and the ground lift. It is also packaged in a smaller case and it has less colors and printing screens on it. All of these help to reduce costs to make the Pro48 more affordable.

So why would someone buy the J48 if the Pro48 costs less?
The J48 feature set provides added benefits for concert performance that may not be needed for the average stage. For instance, the stereo to mono merge function can save valuable channels on a snake and mixer in pro touring. This function also allows you to set-up redundant systems for a computer, digital playback system or keyboard to allow backups should a catastrophic crash occur during a show. Furthermore, engaging the high-pass filter adds even more headroom by eliminating unwanted low frequencies. Finally, being able to rack-mount the J48 for larger keyboard setups is a God-send as it provides for better inventory management.

Can I use the Pro48 on keyboards?
Yes. Absolutely! The Pro48’s higher level handling coupled with the -15dB pad make it very well suited for today’s high output keyboards. Without the pad engaged, the Pro48 is also perfectly suited for older low-output keyboards like a Rhodes piano or a vintage synthesizer.

How does the active Pro48 compare to the passive ProDI?
This is like comparing a dynamic microphone to a condenser. Just like condenser mics, active DIs like the Pro48 have more reach and are more sensitive than dynamic mics or passive direct boxes. This makes the Pro48 active DI a better choice for lower output devices while the passive ProDI is better suited for very high output devices. In the end, it is really a matter of personal preference.

If 48 phantom requires the ground wire to be connected, how do you lift the ground?
The Pro48 employs a digital switching supply that converts phantom power to produce more headroom. As phantom is required to power the J48, we do not lift the ground at the XLR as we would with a passive DI. Instead, we lift the ground inside the power supply. Tricky!

If I only have a master 48V phantom power switch on my mixer, will turning on phantom power affect the other microphones?
No. Phantom power is designed to supply condenser microphones and active direct boxes. It has no effect on dynamic mics or passive direct boxes. The only possible concern is with vintage ribbon microphones which are rarely if ever used with PA systems.

• Audio circuit type: Proprietary analog circuit with low-noise op-amp
• Frequency response: 20Hz ~ 20kHz (± 1.5 dB
• Dynamic range: 99dB
• Total harmonic distortion: 0.001% @ 0 dBu
• Intermodulation Distortion: 0.002% @ 0 dBu
• Phase Deviation: +28º at 20Hz | +1º at 1kHz | -2º at 20kHz
• Input Impedance: 220kΩ - ¼" input
• Output Impedance: 600Ω - XLR output
• Equivalent Input Noise: -86dBu
• Noise: -82dB below 0dBu
• Maximum Input: +9dBu
• Features
• Input pad, Ground lift
• General
• Construction: 14-gauge steel
• Size (L x W x D): 4.25" x 2.75" x 1.75" (108 x 70 x 44mm)
• Weight: 1.2 lb (0.54kg)
• Power: 48V phantom - proprietary digital switching
• Conditions: For use in dry locations only between 5°C and 40°C
• Warranty: Radial 3-year, transferable