www.radialeng.com
Radial Engineering Ltd.
1845 Kingsway Ave., Port Coquitlam BC, V3C 1S9, Canada
Tel: 604-942-1001 • Fax: 604-942-1010 • email: [email protected]
ProD2D2
™™
Passive Stereo
Direct Box
ProDI
™™
Passive
Direct Box
User Guide
®
True to the Music
WELCOME
Congratulations on your purchase of the Radial ProDI or ProD2 direct box, two of the most versatile and useful pieces of
equipment you will likely ever own! Why do we say this? Simple: a good passive direct box can often fi nd its way into all
kinds of applications and be a real problem-solver for both live PA systems and studio recording. For example, the ProDI
can be used to eliminate noise, split signals, convert unbalanced lines to balanced, and can be used backwards to send
pre-recorded signals to a guitar amp for an eff ect called re-amping.
As with all Radial products, every attempt has been made to make the ProDI ‘plug & play’ easy-to-use. However, it is still
a good idea to read this manual thoroughly to ensure you take full advantage of all the features that are built-in, so that the
results you get are the very best possible. Should you have any questions on your new ProDI, please consult the Radial
website FAQ section, as this is where we publish questions and answers from users after a product has been released.
If you do not fi nd the answer you are looking for, feel free to send us an email at [email protected] and we will do our
very best to get back to you promptly.
TABLE OF CONTENTS PAGE
Introduction .............................................................................. 1
Features ..................................................................................2
Making connections ................................................................. 3
Frequently asked questions.....................................................4
Block diagram and specifi cations ............................................5
Warranty ....................................................................Back cover
ProDI and ProD2 User Guide
Note: This manual covers the single channel ProDI and the
stereo two channel ProD2. As both devices are virtually
identical, this manual will discuss the ProDI.
Radial Engineering Ltd. ProDI
™
User Guide
INTRODUCTION
The Radial ProDI is a passive direct box. This means that unlike active direct boxes that either require a battery or power
of some sort to make them work, your ProDI does not need any power at all. It is ‘plug & play’ easy-to-use.
A direct box is primarily used to convert a high impedance instrument signal to a
low impedance balanced mic-level signal, which can then be processed
like a microphone and driven through long cables to the PA without
introducing noise. The ProDI employs a high quality, custom
designed impedance-matching transformer to do the conversion.
Typical applications for the ProDI are connecting electronic
instruments like guitar, bass, keyboard, and drum machines
directly to a PA or recording system. Because the output of
the ProDI matches that of a typical microphone, the ProDI
is perfectly suited for use in live sound and recording studio
systems where microphone signals are put through long
cable systems to a mixing console and where all signals are
balanced to keep noise down.
True to the Mu sic
1
Radial Engineering Ltd. ProDI
™
User Guide
FEATURE SET
True to the Music
2
1. 1/4" INPUT: Instrument input used to
connect to the direct box.
2. 1/4" THRU-PUT: Parallel output used
to connect the instrument signal to an
amplifi er.
3. -15dB PAD: Reduces the input signal to
prevent distortion.
4. BOOKEND DESIGN: The bookend
cover provides protection to switches
and connectors.
5. XLR OUT: balanced, low impedance
mic-level output. Wired with AES
standard (pin-2 hot).
6. GROUND LIFT: Disconnects pin-1 at
the XLR output to reduce ground loops.
7. FULL BOTTOM FOAM PAD: Isolates
the DI from the amp chassis and keeps
it from sliding around on busy stages.
8. STEEL ENCLOSURE: Ultra rigid I-beam
design eliminates stress that could
torque the PC board and cause solder
joint failure.
9. RADIAL TRANSFORMER: Custom
designed transformer offers outstanding
audio performance.
10. DOUBLE-SIDED PCB: Military-grade
PCB with plated through-holes is bolted
to welded steel standoffs.
9
8
1
7
2
3
10
4
6
1. LEFT & RIGHT 1/4" THRU-PUTS:
Parallel outputs used to connect the
instrument signals to an amplifi er.
2. LEFT & RIGHT -15dB PAD: Reduces
the input signal to prevent distortion.
3. LEFT & RIGHT 1/4" INPUT: Instrument
inputs used to connect to the direct box.
4. BOOKEND DESIGN: The bookend
cover provides protection to switches
and connectors.
5. LEFT & RIGHT XLR OUT: balanced,
low impedance mic-level output. Wired
with AES standard (pin-2 hot).
6. GROUND LIFT: Disconnects pin-1 at
the XLR output to reduce ground loops.
7. FULL BOTTOM FOAM PAD: Isolates
the DI from the amp chassis and keeps
it from sliding around on busy stages.
8. STEEL ENCLOSURE: Ultra rigid
I-beam design eliminates stress that
could torque the PC board and cause
solder joint failure.
9. RADIAL TRANSFORMER: Custom
designed transformer offers outstanding
audio performance.
10. DOUBLE-SIDED PCB: Military-grade
PCB with plated through-holes is bolted
to welded steel standoffs.
5
9
8
1
10
3
2
6
2 4
5 7
ProDI ProD2
Radial Engineering Ltd. ProDI
™
User Guide
True to the Music
3
MAKING CONNECTIONS
Using the Radial ProDI is easy. Before connecting, start by making sure all volume levels are set to zero and the audio
system is turned off . This will avoid any loud pops in your sound system that could cause system damage. The ProDI does
not require any power and it will ignore the phantom power from your mixer, if it is turned on.
Begin by connecting the instrument or source device to the INPUT connector on the ProDI. The THRU connector would
be used to connect the signal from the instrument to the musician’s stage amplifi er. For line-level sources, the THRU
connector may be used to feed a second mixer, recorder, or active monitor speaker.
Finally, connect the ProDI’s LOW-Z OUT to the microphone input of a mixing console or other suitable device. Often the
ProDI’s output will connect through a microphone snake system to a mixing console.
Once your cables are connected, you can turn your system on and turn the volume up. Start at a low volume to make sure
everything is working properly. If you encounter any buzz or hum, try lifting the ground switch on the ProDI. If you hear any
distortion, check the input at your mixer fi rst and then, if your input controls appear normal, try depressing the input PAD
switch on the ProDI. This will reduce the input sensitivity by -15dB and eliminate distortion caused by ultra-high output
sources. After depressing the PAD switch, the mixer input controls may have to be readjusted.
Inputs
Thru-puts
Balanced
Out
Input
Thru-put
Balanced
Out
Radial Engineering Ltd. ProDI
™
User Guide
True to the Music
4
FAQ
Why is the ProDI's output not as loud as the output from a keyboard or active preamp?
The ProDI is a passive direct box and is designed to produce a microphone level signal. This allows the ProDI to be used
alongside other microphones in a snake system and connect to the microphone input on a mixing console.
Will phantom power hurt my ProDI or devices connected to it?
No. Phantom power will simply be ignored by the ProDI as well as blocked from reaching any device connected to it.
Do I really need a DI? Can I not simply connect my instruments directly into the mixer?
Of course you can! Instruments can connect directly to a mixer using a hi-Z unbalanced “guitar” cable up to 20 feet
long. The advantage of using a high quality direct box is lower noise and proper impedance matching. This will result in
better sound, especially when connecting to professional audio equipment that accepts balanced signals and/or when the
instrument signal must travel through cables longer than 20 feet to a mixing console.
I heard active direct boxes can be better than passive. Is this true?
Both active DIs and passive DIs have their place in professional audio, just like condenser and dynamic mics do. Active DIs
can have more ‘reach’ and enhance the sound of some instruments. Passive DIs tend to handle more level than active DIs.
The real advantage of passive DIs over active ones is that they eliminate hum & buzz caused by ground loops by using a
transformer to isolate the input signal from the output.
Can I use a piezo pickup with the ProDI?
If your piezo equipped instrument has it's own pre-amp and battery (active piezo pickup) you can use the ProDI with
excellent results. If your piezo equipped instrument does not have a pre-amp (passive piezo pickup) then you really need
to have a higher input impedance to get the best signal output. The Radial JDV and PZ-Pre include a piezo feature with a
very high input impedance that is perfectly suited for passive piezo pickups.
Radial Engineering Ltd. ProDI
™
User Guide
True to the Music
Radial Engineering Ltd. ProDI
™
User Guide
5
ProD2
ProDI and ProD2 Specifi cations
Frequency response: 20Hz to 20kHz +/- 2.5dB
Total harmonic distortion: 0.01 % from 20Hz to 20kHz
Input impedance: 140K ohms (with 1kHz input)
Balanced outputs: 150 ohms, -60dB mic level, pin-2 hot
PAD: -15dB
ProDI
BLOCK DIAGRAM AND SPECIFICATIONS
www.radialeng.com
RADIAL ENGINEERING
3 YEAR TRANSFERABLE WARRANTY
RADIAL ENGINEERING LTD. (“Radial”) warrants this product to be free from defects in material and workmanship and will
remedy any such defects free of charge according to the terms of this warranty. Radial will repair or replace (at its option) any
defective component(s) of this product (excluding fi nish and wear and tear on components under normal use) for a period
of three (3) years from the original date of purchase. In the event that a particular product is no longer available, Radial
reserves the right to replace the product with a similar product of equal or greater value. To make a request or claim under
this limited warranty, the product must be returned prepaid in the original shipping container (or equivalent) to Radial or to
an authorized Radial repair center and you must assume the risk of loss or damage. A copy of the original invoice showing
date of purchase and the dealer name must accompany any request for work to be performed under this limited warranty.
This limited warranty shall not apply if the product has been damaged due to abuse, misuse, misapplication, accident or
as a result of service or modifi cation by any other than an authorized Radial repair center.
THERE ARE NO EXPRESSED WARRANTIES OTHER THAN THOSE ON THE FACE HEREOF AND DESCRIBED
ABOVE. NO WARRANTIES WHETHER EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED TO, ANY IMPLIED
WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE SHALL EXTEND BEYOND THE
RESPECTIVE WARRANTY PERIOD DESCRIBED ABOVE OF THREE YEARS. RADIAL SHALL NOT BE RESPONSIBLE
OR LIABLE FOR ANY SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES OR LOSS ARISING FROM THE USE
OF THIS PRODUCT. THIS WARRANTY GIVES YOU SPECIFIC LEGAL RIGHTS, AND YOU MAY ALSO HAVE OTHER
RIGHTS, WHICH MAY VARY DEPENDING ON WHERE YOU LIVE AND WHERE THE PRODUCT WAS PURCHASED.
www.radialeng.com
®
Radial Engineering Ltd.
1845 Kingsway Ave., Port Coquitlam BC, V3C 1S9, Canada
Tel: 604-942-1001 • Fax: 604-942-1010
email: [email protected]
Radial ProDI
™
and ProD2
™
user guide - Part #: R870 1095 00 - Rev2.1 / 09-2021
Copyright © 2009, all rights reserved. Apperances and specifi cations subject to change without notice.
www.radialeng.com
