Radial Engineering J33 User's Guide

Radial Engineering
1638 Kebet Way, Port Coquitlam BC V3C 5W9
Tel: [phone] Fax: [phone]
email: [e-mail]

www.radialeng.com

Radial Engineering is a division of C•TEC (JP CableTek Electronics Ltd.)

J33
Phono Preamp DI
User Guide

1

Radial is a division of JP Cabletek Electronics Ltd.
Specifications and appearance subject to change without notice.
Radial J33 manual V1.1 - 05/20/05 - Part #: R870-1090-00

www.radialeng.com

Radial J33 Phono Preamp DI
Users Guide

Table of Contents Page

Introduction ...................................................................... 2

Feature Set ...................................................................... 2

Input Panel ...................................................................... 4

Output Panel ................................................................... 5

Making Connections ........................................................ 6

FAQ ................................................................................. 8

Specifications .................................................................. 9

Warranty ....................................................................Back Cover

J33 User Guide

True to the Music

Radial Engineering

Congratulations on your purchase of the Radial J33 combination
turntable preamp and direct box. This handy device has been
developed to interface a conventional turntable with magnetic
cartridge to both professional balanced audio systems and con­sumer unbalanced hi-fi systems.

As with all Radial products, every attempt has been made to
make the J33 ‘plug & play’ easy-to-use. However, please read
this manual thoroughly to ensure the best possible results.

Should you have any questions on your new J33, please con­sult the Radial website FAQ section as this is where we publish
answers from users after a product has been released. If you do
not find the answer you are looking for on-line, please feel free
to send us an email at [e-mail] and we will do our
very best to get back to you promptly.

Now dust off that old Perry Como Christmas record, pour your­self some eggnog and enjoy!

INTRODUCTION

Since the advent of the compact disc, the use of long-playing
records has become so sparse that it has become difficult to
find a hi-fi receiver that is equipped with a phono input. With
literally millions of albums floating around the world, a need
has emerged to capture these recordings and transfer them to
today’s digital formats.

The Radial J33 provides a solution with a simple device that is
‘plug & play’ easy-to-use and built to Radial’s professional stan­dards for sound quality and durability. Equipped with an RIAA
preamp and choice of -10dB consumer line-level and pro 600Ω
mic-level outputs, the J33 is right at home in the studio, on the
stage and in the DJ booth.

For the enterprising studio, this opens the door to a new busi­ness opportunity: a phono to CD transfer service that offers
families a way to enjoy their favorite LP’s in their cars and on
their new surround sound systems. The Radial J33 also boasts
other advantages: for the broadcast station and museum, old
record collections can now be easily archived by transferring
phono recordings to digital media. With the plethora of digital
‘noise-eliminating’ software, less than ideal recordings can now
be updated to approach today’s signal-to-noise expectations.

For the recording studio, the emergence of ‘scratching’ in hip­hop, rap and pop music opens the door to better recordings and
more creativity by allowing a turntable to connect through high­end processing, opening up opportunities for re-recording and
greater artistic freedom.

FEATURE SET

The Radial J33 is a combination RIAA phono preamp and active
DI that allows you to connect a conventional turntable with mag­netic cartridge to a recording system, hi-fi or PA system.

The J33 features a pair of stereo inputs for the turntable. A
ground lug is provided to properly ground the turntable to avoid
system noise. This signal then feeds the preamp that boosts the
phono signal while introducing the RIAA equalization curve.

Next to the turntable inputs are a series of unbalanced -10dB
consumer line-level outputs. These include a stereo set of RCA
connectors that can connect to the auxiliary or CD inputs on a
typical hi-fi receiver; a 1/8” (3.5mm) stereo mini-jack that can
connect to an MP3 player or computer sound card and a ¼” TRS
connector that can be split using an insert cable to a pair of 1/4"
line inputs on a PA or DJ mixer.

The J33 is also equipped with a low-frequency rumble filter. This
gently rolls off the bass to reduce the low frequency rumble and
resonant feedback that can occur when spinning records in high
volume environments such as on stage or in nightclubs.

True to the Music

2

J33 User Guide

Radial Engineering

True to the Music

3

Radial Engineering

J33 User Guide

To connect to professional balanced systems, the Radial J33 is
equipped with a pair of male XLR connectors. The active bal­anced drivers convert the signal to a low impedance (600Ω),
microphone level, stereo signal. The J33’s balanced XLR out­puts can drive turntable signals well over 100 meters (328 feet)
without appreciable loss or noise. This makes the J33 ideal for
driving turntable signals through a snake system on stage and
through the patchbays and complex wiring systems that abound
in the professional studio.

The Radial J33 may be powered with 48V phantom or with the
included 15VDC power supply. The J33 will automatically select
the power source and the two LED on the front panel will illumi­nate, indicating power is present.

This is the RIAA EQ curve that the J33 applies to the turntable
signal. The exact opposite curve was encoded into the signal
when the vinyl LP was pressed.

RIAA PREAMP

An RIAA phono preamp is a device that boosts the signal
from a turntable and applies a pre-defined equalization
curve. The RIAA equalization curve is applied as pre-em­phasis EQ during the cutting of the metal master, and as a
de-emphasis EQ on playback. In other words, a record is
cut with the low frequencies reduced and the high frequen­cies boosted (pre-emphasis), and on playback the opposite
occurs (de-emphasis). The RIAA preamp in the J33 pro­vides this required de-emphasis EQ.

The result is a flat frequency response, but with noise such
as hiss and clicks arising from the surface of the record it­self reduced (or “attenuated”). The RIAA equalization curve
has operated as a global industry standard for the record­ing and playback of vinyl records since 1954.

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