Radial Engineering
1638 Kebet Way, Port Coquitlam BC V3C 5W9
Tel: 604-942-1001 Fax: 604-942-1010
email: info@radialeng.com
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 info@radialeng.com 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
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J33 User Guide
Radial Engineering
True to the Music
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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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True to the Music
Radial Engineering
J33 User Guide
INPUT PANEL FEATURES
1. LED power indicator
For left and right channels. Illuminates when the 15VDC
power supply is connected or when 48V phantom power is
applied from a mixing console.
2. Rumble filter
Applies a high pass filter (bass roll-off) when pushed in.
3. Gound lug
Attatches to the turntable ground wire.
4. 3.5mm stereo output jacks
-10dB (consumer level) stereo output for direct connection to
computer sound cards, laptops or any device with a 3.5mm
input. This connector is also known as 1/8" TRS
5. 1/4" stereo output jack
-10dB (consumer level) stereo output for direct connection to
a local mixer, recorder or any device with a 1/4" TRS input.
6. RCA stereo output jacks
-10dB (consumer level) stereo outputs for direct connection
to a hi-fi receiver AUX or CD input or any device with an
RCA input.
7. RCA phono (turntable) input jacks
RIAA equalized stereo input for turntable signals. Use in conjunction with the gound lug.
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True to the Music
Radial Engineering
J33 User Guide
OUTPUT PANEL FEATURES
8. Bookend design
14 gauge steel outer shell creates protective zone around
connectors and switches and wraps around a welded case
with I-beam construction for maximum durability. Finished in
tough baked enamel.
9. Left and right XLR outputs
Balanced low impedance (600Ω) microphone level outputs.
Connects to mic input on mixing console.
10. 15VDC power supply connection
The 15VDC power supply is connected here for powering
the J33. There is no power switch and leaving the J33 on
will not harm it. This jack is not used if the J33 is powered
with phantom power from a mixing console. When switching from 48V phantom power to the external DC supply, or
back, please wait 15 seconds to allow the RIAA amplifier to
charge and stabilize.
11. Full-bottom no-slip pad
This provides electrical and mechanical isolation plus
plenty of "stay-put" friction to keep the J33 in one place.
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True to the Music
Radial Engineering
J33 User Guide
MAKING CONNECTIONS
Using the Radial J33 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.
Begin by connecting the turntable outputs to the J33 using the
RCA connectors and securing the ground lead from the turntable
to the ground lug on the J33.
The J33 may be powered in two ways. The fi rst is with 48V
phantom power from a mixing console. The second is with the
J33’s external 15VDC supply. To use 48V phantom power the
J33 must be connected using its XLR connectors to a mixing
console equipped with phantom power. If your mixer is not
equipped with phantom power or if you are connecting to unbalanced systems through the J33’s RCA, 1/8” and ¼” connectors
you will need to use the J33’s external 15VDC power supply.
Performance is identical with either power supply and the J33
will automatically select the power source depending on how
you have it set up. As soon as you connect the J33’s external
15VDC power supply or turn on the mixers phantom power, the
J33’s front panel LED indicators will illuminate. When switching
from 48V phantom power to the external DC supply, or back,
please wait 15 seconds to allow the RIAA amplifi er to charge
and stabilize.
Make the connections from the J33 to whichever piece of gear
you would like. The unbalanced -10dB outputs are commonly
known as consumer line-level outputs. These will drive inputs
found on hi-fi equipment and the unbalanced line-level inputs
found on mixing consoles. The balanced XLR outputs on the
J33's rear panel are mic-level so that they will match up with
Left RightGround
Detail of turntable connections showing the left and right
signal outputs and the turntable's spade ground lead.
True to the Music
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Radial Engineering
J33 User Guide
other direct boxes and microphones, thus enabling the J33 to
be used along with microphones in snake systems, mic splitters
and through console mic preamps.
You can use any or all the output connectors at once, enabling
you to, for instance, connect your turntable to the J33, the -10dB
RCA line-level outs to a DJ mixer and the balanced XLR outs to
a PA system. Depending on how the equipment is connected
to the AC mains, there can be a potential for ground loop hum
when using both the balanced and unbalanced outputs at the
same time. If a ground loop hum develops, a possible solution
is to lift the ground at the PA mixer and use the J33’s 15VDC
external power supply.
Once your connections are made, turn on the sound system.
Begin at low volume to make sure the sound system is working
properly, get your favorite album and listen. The sound should
be clear. If you hear any hum or buzz, check the ground wire,
as this is the usual culprit. It should be fi rmly held by the J33’s
ground lug. If you are driving your system at high volume levels
and begin to hear low frequency resonance, try depressing the
rumble fi lter. This will usually tame low frequency PA system
feedback.
You are now ready to spin away! Have fun!
MP3 Player
Mixing Console
CD-R Recorder
Dashed line represents
turntable ground wire.
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Radial Engineering
J33 User Guide
FAQ
What is an RIAA pre-amp and why do I need one?
When vinyl albums are produced, a preset EQ curve is introduced. This EQ curve is the RIAA phono response curve and has
been a standard since the introduction of the long play record or
LP. The RIAA response curve was developed to get better performance out of the medium. When the record is played back the
signal needs to be restored by applying the exact opposite EQ
curve as the one introduced during production. This is what the
RIAA preamp section of the Radial J33 is doing. Without an RIAA
preamp, LPs would not sound as they were intended to.
Can I use an active phono cartridge with the J33?
No. The J33 is designed to use magnetic cartridges which make
up 99% of all turntable cartridges ever sold.
What should I do if I depress the rumble filter and still have
feedback?
Try using an isolation pad such as the Primacoustic IsoPlane
(www.primacoustic.com). This will reduce the vibration going
into the turntable and help eliminate low frequency resonant
feedback.
Can I connect other devices such as keyboards or computer sound cards to the J33's input?
No. The J33’s input is pre-equalized with the RIAA curve. This
curve is designed for LP records and would make any other
source sound bad, plus these line-level devices would overload
the J33’s sensitive input circuit and cause distortion.
Why is there no ground lift on the J33?
Because the ground lift would disconnect the pin-1 on the XLR,
which in turn would shut off the phantom power.
Can I rackmount the J33?
Yes. The Radial J-Rak will allow as many as 8 direct boxes to
be rack-mounted in two RUs. Go to the Radial website for more
details on the J-Rak. (www.radialeng.com)
What should I do if the LEDs do not light up?
Check that the external power supply is connected or, if connecting to a mixer through the J33's XLR outputs, make sure the 48V
phantom power has been turned on at the mixer.
Can I record an album directly to my computer sound card
using the J33?
Yes. Most sound cards are equipped with a 3.5mm input connector. Connect the line-level output of the J33 to the computer
and you should be set to go. Sound card input levels vary, so
watch for distortion as the output of the J33 is quite hot. Your
computer sound card software should allow you to pad down the
input should this be a mic-level input.
How will the J33 sound with my hi-fi system?
Great! The J33 is a low noise preamplifier and will out-perform
the typical RIAA preamp built into consumer hi-fi equipment.
True to the Music
J33 BLOCK DIAGRAM
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Radial Engineering
J33 User Guide
True to the Music
J33 Specifi cations
Frequency response 20Hz ~ 20KHz ±3dB
Total harmonic distortion 0.005 % @ 1KHz
RIAA curve +19.5dB @ 20Hz
-19.65dB @ 20kHz
Reference: 0dB @ 1kHz
RIAA deviation +/- 0.5dB maximum
Max. phono input level 50mV @ 1KHz
High pass fi lter 200Hz cut off, -3dB at 100Hz
Unbalanced outputs 10kOhm, -10dB line-level
Balanced outputs 600Ω, -60dB mic-level
XLR pin confi guration AES standard: pin 1 ground
pin 2 hot (+)
pin 3 cold (-)
Power (auto-switching) 15VDC or 48V phantom
Size (W x D x H) 3.25”x 5”x1.75” (83x126x45mm)
Weight 1.5 lbs. (.7 kg)
Warranty 3 Years
True to the Music
1638 Kebet Way, Port Coquitlam BC V3C 5W9
tel: 604-942-1001 fax: 604-942-1010 email: info@radialeng.com
www.radialeng.com
Radial J33 users guide V1.1 - 05/20/05 - Part #: R870 1090 00
RADIAL ENGINEERING
3 YEAR LIMITED WARRANTY
RADIAL ENGINEERING (a division of J.P Cabletek Electronics Ltd.) warrants this product to be free from defects
in material and workmanship to the original owner 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 batteries, finish 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 modification 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 FROM STATE
TO STATE OR PROVINCE TO PROVINCE.
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