RADIAL JDI Passive DI Box

The Radial JDI is a passive direct box designed to handle extreme signal levels without distortion of any kind. Unlike an active DI that is limited by the buffering amplifier’s rail voltage, the JDI employs a Jensen audio transformer as the engine. Jensen transformers are legendary in their ability to gracefully handle transients while delivering a smooth, warm sounding Bessel curve, reminiscent of the finest vintage gear. Ruler flat from 10Hz to 40kHz and with virtually zero phase deviation, the JDI delivers the natural, pure sound of the instrument without artifact.

The 100% passive circuitry inside the JDI is incredibly efficient. The transformer performs both high-to-low impedance conversion and signal balancing at the same time with minimal loading and does so without any power whatsoever. The transformer also introduces a magnetic bridge that passes signal while rejecting stray DC voltage. This makes the JDI particularly adept at eliminating hum and buzz caused by ground loops.

Features include input and throughput ?” connectors, -15dB input pad, ground lift, and 180? degree polarity reverse to help phase align the instrument with the PA. A secondary circuit is added for direct interfacing with high output devices such as guitar or bass amp loudspeakers plus a unique merge function allows stereo sources such as keyboards to be summed mono, saving valuable input channels.

Built tough to handle the abuse of live touring, the JDI features a 14-gauge steel I-beam inner frame and a unique book-end outer shell. The innovative design eliminates stress on the PCB, reducing opportunity for solder joints to go ‘cold’ while the outer shell creates a protective zone around the switches and connectors. The steel casing resists noise-causing electromagnetic pollution and the transformer’s sensitive inner workings are further protected from magnetic fields with a MuMETAL® can. This ensures the signal transfer is quiet and free from hum. These combined features have made the Radial JDI the most popular passive direct box in professional touring and an excellent choice for instrument interface in the studio!

The Radial JDI… the world\'s finest passive direct box.

• No. of channels: 2
• Passive/Actibe: Passive
• Transformer balanced: Yes
• Attenuator: -30 dB
• Input/Output Gain: -20 dB
• Ground lift switch: Yes
• Max Input Level: +54 dBu
• Max Output Level: +4 dBu
• Frequency Range  2K Source Imp. -1dB: 10 Hz - 40 kHz
• Input Impedance  60Hz: 60 kΩ
• Nom. Output Impedance: 600 Ω
• Housing: Steel
• Dimension: 110 x 110 x 45 mm

Active DI-Box SM-60

The electronic Direct-Injection Box SM-60 allows direct connection of electronic
music instruments such as keyboards, synthesizers, electric and electronic pianos,
etc. with mixing consoles in PA-systems and in recording studios.
The SM-6 is designed for applications, where a passive DI-Box does not perfom
satisfactorily, i.e., where the output level of a passive DI-Box is too low for the microphone
input section of the mixing desk.
Because the input impedance of the SM-6 is above 5 MOhm, instrument outputs are
not loaded or in any other way adversely affected. The voltage ratio from input to output
is 1: 1 and is always sufficient for connection with any microphone input. Input connectors
are 1/4" phone jacks, output connector is a Switchcraft D3M; output is 600 Ohms,
transformer balanced. The output level may in certain cases overload microphone inputs -
the line input section of the mixing console must then be used for connecting the SM-6.
The unit operates with a 9 V battery or phantom powering from 24 to 48 volts.

Technical Data

input impedance > 5 MOhm
max. input impedance + 6 dBu, 1,55V
ouptut impedance 600 Ohm
frequency response 20 ... 20000 Hz, ± 0,2 dB
gain 1 : 1
THD < 1 % at 30 Hz
       < 0,7 % bei 40 Hz
powering  9-V battery (IEC 6LF22) or
                 phantom power 24 ... 48 V.
inputs  two 1/4" phone jacks , unbalanced
          (one being used as output to instruments amp)
outputs  XLR, balanced
             pin 1 = ground, pin 2 = hot, pin 3 = cold
case aluminium die-cast
weight 240 g
dimensions 113 x 71 x 37 mm

Phantom or battery powered in a rugged steel chassis, with separate Speaker Level input connector
 
The ARX DI-PLUS represents another major step forward in active direct boxes. Packaged in
a single channel stand-alone format, the DI-PLUS represents a fresh look at active D.I. concepts.
Precision engineered
Ultra quiet, ultra clean circuitry delivers maximum headroom whatever the signal. Premium grade
components, plus an all-steel chassis gives excellent hum and noise specifications and superb
audio quality in a tough, roadworthy package.
Level control
The DI-PLUS features a Normal gain high impedance unbalanced input on the front panel, running to
a balanced XLR output on the rear. There is also a separate -40dB Speaker Level input for signal coming
from the External (auxiliary) speaker output of an amplifier. A a global Pad switch drops both the normal
input and the speaker input by a further 20dB, making it suitable for all applications, from the softest
keyboard to the hottest broadcast levels.
 
Battery compartment
The revolutionary simple 'clamshell' action of the DI-PLUS battery compartment makes battery changing
extremely easy, even on the darkest stages.
A 9v alkaline battery snaps into a PCB mounted battery holder for fast, secure location. No fragile battery
clip leads to break, no tools required, no screws to lose. Production crew heaven!
 
Automatic Phantom switching
The DI-PLUS will automatically switch itself to the console's own Phantom Power, if available, and an LED
will indicate this mode. Turn the Phantom Power off and it will instantly revert back to battery mode.
Rugged all-steel case
A lot of direct boxes are fitted into brittle cast alloy cases. Not this one! The tough all-steel inner and outer
chassis of the DI-PLUS provide excellent RF/EMF shielding while making it a sturdy, heavy duty unit that is
hard to dislodge, and hard to leave behind.
 
Rear panel showing XLR connector, ground lift switch, and captive screw for opening up the unit
for battery changing
 
Whether you're a Studio or Live Sound engineer, installation contractor, or broadcast engineer, you want all
the dynamics and clarity of the original sound source transferred to the mixing console. The ARX DI-PLUS
provides a rugged, no-compromise solution to all direct injection and signal balancing requirements.
 
T E C H N I C A L  S P E C I F I C A T I O N S:
Max Input Level
+13 dB Phantom powered
+6 dB Battery powered
Input Impedance 1 Meg Ohm
Max Output Level
+17 dB 10K Ohm load Phantom powered
+12 dB 10K Ohm load Battery powered
+11 dB 600 Ohm load Phantom powered
+12 dB 600 Ohm load Battery powered
Output Impedance 680 Ohms Balanced
Output Signal to Noise
-100 dB unweighted
-104 dB A weighted
Dynamic Range
117 dB 10K Ohm load Phantom powered
112 dB 10K Ohm load Battery powered
111 dB 600 Ohm load Phantom powered
107.5 dB 600 Ohm load Battery powered
Distortion
100 Hz .0027%, 1KHz .0028%, 10KHz .0037%
Frequency Response 20Hz to 20KHz, ± 0.2 dB
Gain through Unit: 6dB (Normal input, Pad switch out)
Pad Switch: -20 dB attenuation
Speaker Input
-40 dB attenuation, equivalent to 100:1 decrease in input level
-60 dB attenuation available with Pad switch
Input Connectors
Insulated jacks (!!!Note that the Input connector switches the unit on
when a plug is inserted. Remove plug when storing to avoid battery drain!!!)
Output Connector
3 pin XLR. Wired Pin 1 Ground, Pin 2 + Hot, Pin 3 - Cold.
With Audio Ground (Pin 1) lift switch
Construction
All-steel chassis, fibreglass PCB
Battery Access
Twist connector opens chassis, snap-in battery holder inside.
No tools required