Description

ProD8 by Radial Engineering is an 8-channel passive Direct Box in 19'' rack format, offering high-performance audio, ideal for keyboard setups in professional touring. It features redundant A/B 1/4" inputs with an Insert for each channel, 180° polarity inversion, Ground Lift to prevent noise induced by ground loops, -15db attenuation pad, and passive circuitry that does not require power.

Key Features

    
• 8-channel DI box in 19'' rack format, ideal for keyboard setups
    
• Reversible rack ears to optimize patching configuration
    
• Resistant to high dynamics
    
• Redundant inputs allow for a backup system

ProD8 Performance

ProD8 provides up to 8 Direct Box outputs in a single 1RU rack space, ideal for professional touring, with dual 1/4" inputs on each channel to integrate a backup system or connect up to 16 audio channels simultaneously. A 1/4" TRS effects insert jack on each channel allows connection to various devices, increasing routing versatility, while a thru-put jack can provide a direct feed to the musician's monitoring system. The front panel features isolated XLRs with low-noise balanced outputs, each equipped with ground lift and 180° polarity inversion switches.

Transformer-based ProD8 for greater Headroom and low noise

The heart of the ProD8 is an Eclipse ET-DB2 transformer with custom windings, performing both impedance matching and balancing. It boasts a linear frequency response from 20Hz to 20kHz, and is capable of withstanding the high dynamic levels of modern digital keyboards. Unlike active circuits that tend to overload and produce a square wave when the rail voltage is exceeded, transformers saturate instead. This means that as the signal increases, the ProD8 naturally rounds out the timbre, producing a warm Bessel curve, a characteristic reminiscent of the best vintage audio devices. The other significant advantage of passive circuitry is the 100% galvanic isolation between source and destination, which eliminates hum and noise caused by ground loops.

Adaptable Configuration

The Radial ProD8 features reversible rack ears that increase its configuration versatility. This feature allows the engineer to position the inputs on the front of the rack when connecting keyboards, or to have them inside if the setup mainly consists of rack modules.

Practical Applications of ProD8

Using ProD8 in the studio

You can set up the ProD8's rack ears so that the ¼-inch jack inputs are on the front panel to facilitate assigning different instruments. This provides access to the dual inputs and thru-put jacks for quick connection to studio amplifiers.

Using ProD8 with rack synthesizers

The ProD8 can be configured with the XLR outputs facing forward for connecting rack synthesizer modules. With the ¼-inch jack inputs facing into the rack for connection to synthesizers, the sound engineer can use the XLR outputs to connect to the main PA snake.

Using ProD8 for playing back music tracks

The ProD8's dual summed inputs make it ideal for simultaneously connecting two sources on each channel. This allows the ProD8 to be used for playing backing music tracks from two multitracks in sync at the same time, or for connecting redundant keyboard setups for live performances.

Radial ProD8 Technical Specifications

    
• Audio circuit type: Passive, transformer-based
    
• Transformer: Eclipse ET-DB2, 12:1 ratio
    
• Number of channels: 8
    
• Frequency response: 20Hz ~ 18.5KHz (± 0.2dB)
    
• Dynamic range: 128dB
    
• Total harmonic distortion: 0.01% from 20Hz~20kHz @-10dB
    
• Phase deviation: 1° @ 100Hz; 8° @ 20Hz
    
• Input impedance: 140k Ohms, unbalanced
    
• Output impedance: 150 Ohms, balanced
    
• Maximum input level: +18dB @ 20Hz

Features

    
• Attenuation pad, 180° polarity inversion, Ground lift
    
• Input connectors: 1/4" Jack
    
• Output connectors: XLR

General Specifications

    
• Construction: 14 gauge steel frame and outer shell
    
• Size (L x W x D): 48.3cm x 15.875cm x 4.45cm - 19" x 6.25" x 1.75"
    
• Weight: 3.26 kg - 7.2lb
    
• Power: Passive, no power required
    
• Operating conditions: dry locations only between 5°C and 40°C