Technical Pro PRE50 User manual

Technical Pro
User Manual for:
PRE50
Professional Pre - Amplifier
with USB & SD Card Inputs

Congratulations and thank you for your purchase of this Technical Pro professional Pre - amplifier, the PRE50. To get the most from your
PRE50
, it is recommended that you review all of the information provided in this instruction manual before operating this equipment.
If you've spent any time at all in professional audio, you know the name Technical Pro and what it stands for — incredible performance &
sound, and the ultimate in reliability under harsh conditions. And now, Technical Pro offers the same technology in a series of Pre - amplifier
bringing more of what sets Technical Pro apart from all others.
1- Read these instructions thoroughly before using this item.
2- Keep these instructions for future reference.
3- Heed all warnings.
4- Follow all instructions.
5- WARNING: To prevent fire or electric shock, do not expose this equipment to rain or moisture. Do not store or operate this
product near any liquids.
6- Clean only with a dry cloth.
7- Do not store or operate this product near any heat sources such as radiators, heat registers, stoves, or other apparatuses
(including amplifiers) that produce heat.
8- Do not defeat the safety purpose of the polarized or grounding-type plug. A polarized plug has two blades with one wider than
the other. A grounding plug has two blades and a round grounding prong. The wide blade or third prong is provided for your safety.
If the provided plug does not fit your outlet, consult an electrician for the replacement of the obsolete outlet.
9- Protect the all wires connected to this unit from being walked on or pinched, particularly plugs and the point where they exit from
the unit. When removing the cord from the power outlet, remove it by holding the plug not by pulling the cord.
10- Unplug the unit during lightning storms or when unused for long periods of time.
11- When wiring this unit and all other equipment used in connection to this unit make sure that all of your equipment is turned OFF.
12- Once installation and wiring is complete power on all your equipment with the volume and level controls turned DOWN. Once
all the equipment is ON slowly raise the volume or level controls to their proper positions.
13- When grounding this unit, be sure to do so correctly, so as not to defeat the built-in grounding in this unit.
14- When you have finished using this unit, be sure that both tray doors are closed using the open / close button before powering
off the unit.
15- Before placing, installing, rigging, or suspending any product, inspect all hardware, suspension, cabinets, transducers,brackets
and associated equipment for damage. Any missing, corroded, deformed, or non-load rated component could significantly reduce
the strength of the installation, placement or array. Any such condition severely reduces the safety of the installation and should be
immediately corrected. Use only hardware which is rated for the loading conditions of the installation and any possible short-term,
unexpected overloading. Never exceed the rating of the hardware or equipment.
16- Consult a licensed, Professional Engineer regarding physical equipment installation. Ensure that all local, state and national
regulations regarding the safety and operation of equipment are understood and adhered to.
17- Refer all servicing to qualified service personnel. Servicing is required when the apparatus has been damaged in any way,
such as power supply cord or plug is damaged, liquid has been spilled or objects have fallen into the apparatus, the apparatus
has been exposed to rain or moisture, does not operate normally, or has been dropped.
WARNING!
CAUTION: TO REDUCE THE RISK OF ELECTRIC SHOCK, DO NOT REMOVE THE COVER OF THIS UNIT. THERE
ARE NOUSER-SERVICEABLE PARTS INSIDE. REFER ALL SERVICING TO A QUALIFIED TECHNICIAN.
The lightning flash with arrowhead symbol within an equilateral triangle is intended to alert the user to the presence
of "dangerous" voltage within the product's enclosure that may be of sufficient magnitude to constitute a risk of
electric shock to humans. Users should exhibit extra safety when this symbol appears in this instruction manual and
follow all precautions as they are stated.
The exclamation point within an equilateral triangle is intended to alert the user to the presence of important
operating and maintenance (servicing) instructions in this manual.
Introduction
PRE50

PRE50 Front Panel
1.Power Button: Press this button to power the unit on and off.
2.Headphone Output: Connect your headphone here.
3. Microphone Input: Connect balanced microphones to this input. This input is compatible with XLR microphone and
¼" microphone.
4.Microphone Level: Use this knob to adjust the volume of the microphones.
5.Bass Control: Use this knob to adjust the bass of the signal from microphones and line inputs.
6.
Microphone Mid Control: Use this knob to adjust the mid level frequencies of the signal from microphones
and line inputs.
7.Treble Control: Use this knob to adjust the treble of the signal from microphones and line inputs.
8.Balance Control: Use this knob to adjust the balance of the signal from microphones and line inputs.
9.MIC & LINE Switch: Press this button to switch the echo controls (Time, Repeat & Balance) between
microphone inputs and Line inputs.
10.Time Control: Use this knob to adjust the time of echo.
11.Repeat Control: Use this knob to adjust the repeat times of echo.
12.Echo Volume Control: Use this knob to adjust the volume of echo.
13.Mono Button: Press this button to mix the signal from LINE input into a mono signal and the indicator will
light up when this function is enableed. Press again to disable this function.
14.PAD Button: Press this button to decrease the signal output by 30dB. Press it again to disable this function.
It only works for Line input signal.
15.Low Out Button: Press this button activate the high-pass filter. The unit will omit the input signal which is
below 30Hz.
16.Loudness Button: Press this button to enable the loudness function and the unit will raise the signal output
by 3dB. Press it again to turn it off.
17.Master Volume Control: Use this knob to adjust the master volume output.
18.Tape Monitor: Press this button to activate the tape monitor function. Press it again to turn it off. Once the
tape monitor function is enabled, connect the REC- OUT of PRE50 to another recording device and connect the
output of this recording device to the PLAY- IN to monitor the recording. There must be a signal coming from the
PLAY-IN once the tape monitor function is enabled. Otherwise there won’t be any volume output from the
speakers.
19.
Next Track / Next 10 Button: Press this button to go back to the beginning of the next track on either the iPod ™
(Classic and Nano) , USB flash drive or SD Card. Press this button and hold for several seconds to quickly go 10
tracks ahead.
20.REPEAT / RANDOM: Press this button to repeat the current track, all tracks or play random tracks on
the USB flash drive,SD card or iPod™(Classic and Nano) inputs. The unit’s default setup is repeating all
tracks. Press this button once to repeat the current track, press again to play random tracks, press three
times to repeat all tracks.
PRE50
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21 23 24 25
22
9

21.USB Input: Insert your USB flash drive or iPod™(Classic and Nano) into this slot. The unit will only read .mp3,
.wav, .wma files from the USB flash drive or iPod™(Classic and Nano).The maximum storage size of the USB
flash drive cannot exceed 32GB. Make sure to press the input selector button (23) to play the signal from the USB
flash drive or iPod™(Classic and Nano).
22.SD Card Input:
Insert your SD card into this slot. The unit will only read .mp3, .wav, .wma files from SD card.
The maximum storage size of the SD card cannot exceed 32GB.
Make sure to press the input selector button (23)
to play
the signal from the SD Card.
23.Mode Selector: Use this button to switch among all the inputs.
24. Play / Pause / Record Button: When the input selected is USB/SD, press this button to pause the
signal from the USB flash drive,SD card or iPod™(Classic and Nano) connected to the USB input. Press
this button again to play.The play/pause function will only work for the USB flash drive,SD card or iPod™
(Classic and Nano). THERE IS NO RECORDING FUNCTION WHEN INPUT SELECTED IS USB/SD.
When the input selected is PHONO/AUX/MP3 and there is an USB flash drive or SD card (with blank
space on it) inserted into their respective slot, pressing and holding this button will activate the
recording function.Press this button and hold for several seconds and the recording indicator on the face
will be illuminated. The unit will create a new file in the connected USB flash drive or SD card and get
ready to makea recording. At this point there is no actual recording yet. Press the button again and the
unit will start recording onto the USB flash drive or SD Card and the recording indicator will start to flash.
Press the button a third time to pause the recording and the recording indicator will stop flashing and be
illuminated. Press again to continue the recording. Press and hold this button for several seconds to
save the file and end the recording and exit. If both USB flash drive and SD card are connected, the unit
will begin recording onto the USB flash drive. If the USB flash drive is full, remove it and then press the
record button again to start another recording. The unit will also be able to record the signal from
microphone onto the USB flash drive or SD Card. When the recording funcion is activated and there is a
microphone connected and have it turned on, the unit will mix the signal from MP3 or AUX with the
microphone’s into one track. If two microphones are connected and turned on, both signal from them will
be recorded and mixed into one track with the signal from MP3 or AUX.
THE RECORDING FILE FORMAT IS .WAV.
25.Previous Track / Previous 10 Button: Press this button to go back to the beginning of the previous track on either
the
iPod™ (Classic and Nano) , USB flash drive or SD Card. Press this button and hold for several seconds to
quickly go10 tracks back.
PRE50

PRE50 Rear Panel
1.Power Supply: Only use the power cord provided with the unit to power the unit. When connecting and
disconnecting the power cord, be sure the power of the unit is off. Connect the cord to the rear of the unit and then
connect it to the outlet.
2.Voltage selector: Select between 230V AC 50Hz / 115V AC 65Hz. When using with a 115V outlet, the unit should
be set to 115V.
3.Ground Lift: Use this switch to turn on/off the
4.Balanced: Connect these outputs to an amplifier’s balanced microphones inputs. The unit should be powered off
and volume levels turned down when making these connections.
5.Group 2 Unbalanced Output: Connect
this unbalanced output to either a recording device, another amplifier or
a powered (active) subwoofer.The signal from the line output is a passive output and cannot be connected directly
to a passive speaker.
6.Group 1 Unbalanced Output: Connect this unbalanced output to either a recording device, another amplifier or
a powered (active) subwoofer.The signal from the line output is a passive output and cannot be connected directly
to a passive speaker.
7.REC-OUT Output: Connect the line output to another recording device and connecting this recording device’s
signal output to the PRE50’s Play-IN Input to monitor the recording. Make sure the “Tape Monitor” button on the
front panel is pressed and tape monitor function is activated when using tape monitor function.
8.Play-IN Input:Connecting the recording device’s signal output to this input to monitor the recording. The recording
device should be the same one the PRE50’s REC-OUT output is connected to. Make sure the “Tape Monitor”
button on the front panel is pressed and tape monitor function is activated when using tape monitor function. Please
note that if the tape monitor function is enbled, there must be a signal coming into the PRE50 from the PLAY- IN
jacks. Otherwise, there won't be any volume output from the speakers.
9.Line Outputs: Connect the line output to either a recording device, another amplifier or a powered (active)
subwoofer. The signal from the line output is a passive output and cannot be connected directly to a passive
speaker.
10. MP3 Input: Connect your MP3 player here.Make sure to press the input select button “ MP3 ” to play the
signal from the MP3.
11.MP3 Input: Connect any stereo signal output such as a DVD, CD, TAPE, Mixer, MP3 etc to this input. To play a
signal connected to this input make sure the MP3 input is selected on the front panel.
12.AUX Input: Connect any stereo signal output such as a DVD, CD, TAPE, Mixer etc to this input. To play a signal
connected to this input make sure the AUX input is selected on the front panel.
13.PHONO Input: Connect any stereo signal output such as a DVD, CD, TAPE, Mixer etc to this input. To play a
signal connected to this input make sure the AUX input is selected on the front panel.
PRE50
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In the typical setup, a user should wire from the output of the signal source directly to one of the RCA
inputs on the rear of the PRE50. Once the input signal source is connected to the PRE50, connect
the amplifier to the PRE50’s unbalanced outputs. Pictured above is a CD player connected to the
PRE50’s AUX input. The PRE50 has three groups of signal outputs. The unbalanced output is
connected to an amplifier. You can also connect the unbalanced output directly to the input of a tape
recorder, and then to the input of the amplifier. The unbalanced output will send the signal from
the selected input (PHONO, AUX, USB Flash Drive, SD Card, iPod™ (Classic and Nano), or MP3
player). There are also a group of balance outputs on the rear panel of the unit. Connect the balanced
output to another amplifier’s balanced input to play balanced signal. The PRE50 has REC Output and
Play-IN Input which are for the tape monitoring function. Press the “ Tape Monitor ” button on the front
panel to activate this function and make sure the REC Output is connected to a tape recorder’s input
and the tape recorder’s output is connected to the Play-IN Input. Otherwise, there won’t be any volume
level output from the speakers for the signal from tape recorder into the PRE50.
PRE50
Typical PRE50 Input and Output Connections
NOTE: WHEN MAKING THESE CONNECTIONS THE POWER OF THE PRE50 AND THE SIGNAL
SOURCE SHOULD ALL BE IN THE OFF POSITION WITH THE VOLUME LEVELS TURNED DOWN.
Amplifier
(AUDIO INPUT)
CD Player
LINE
Left Right
TAPE RECORDER

PRE50
Connecting the speaker wire to the PRE50’s balanced outputs
NOTE: WHEN MAKING THESE CONNECTIONS THE POWER OF THE PRE50 AND THE SIGNAL
SOURCE SHOULD ALL BE IN THE OFF POSITION WITH THE VOLUME LEVELS TURNED DOWN.
LINE
Left Right
Use particular cables to connect the balanced output on the rear panel of PRE50 to another amplifier’s
balanced singal input. It’s important to make sure that the PRE50’s left output is connected to the
amplifier’s left input and PRE50’s right output is connected to the amplifier’s right input.

There are also SD Card and USB flash drive inputs on the front panel of the PRE50 which is compatible with iPod™
(Classic and Nano) via the USB input.
The maximum size of the SD Card or USB flash drive is 32GB. If your memory
card exceeds 32GB, the unit will not be able to read the files from the memory cards. You will only be able to play
.mp3,.wav,.wma files directly from these memory cards once they are inserted into the front panel of the unit. Press
the play/pause button on the front panel of the unit to begin playing files from your USB /SD Card, press this button
again to pause. Press the NEXT button to move to the next track on either the USB,SD Card or
iPod™(Classic and
Nano)
. Press the PREVIOUS button to move to the previous track on either the USB,SD Card or iPod™ (Classic
and Nano)
.
NOTE: THE USB INPUT WILL ONLY CONNECT TO A USB FLASH DRIVE OR iPod™(Classic and Nano). DO NOT
ATTEMPT TO CONNECT THE USB INPUT DIRECTLY TO A COMPUTER AS THIS WILL NOT WORK.BE SURE
NOT TO HOOK-UP AN AMPLIFIER OR ANY AMPLIFIED SIGNAL INTO THE RCA INPUT JACK AS THIS COULD
DAMAGE THE
PRE50 . ALWAYS MAKE SURE THAT THERE IS ONLY ONE AMPLIFIER IN THE SIGNAL PATH.
There is a microphone input on the face of the unit which you can plug microphone directly into. This input is
compatible with XLR microphone and ¼" microphone. It is important to note that this input is to be used solely by
microphones. Do not attempt to use this input for any other use. To use, simply plug the microphones into the input
while the speaker and microphones are in the OFF position.Once plugged in, power on the unit and microphones.
Once turned on, simply turn up the Microphone Volume and the Master Volume.
The microphone input can be controlled on the front panel of the unit. The microphone volume controls can be found
on the front panel of the unit. Use these controls to adjust the volume of the microphones. There is also a group of
echo controls on the front panel of the unit. Use these controls to adjust the sound from the microphones. Press the
“MIC/LINE” button to switch the controls between microphone and line input signals.
Microphone Controls
Connecting Microphones to PRE50
Volume and Tone Controls
The volume controls on the face of the unit controls the volume at which the signal is played at.Turn the volume
controls clockwise to increase the volume and counter-clockwise to decrease the volume.
PRE50
USB Flash Drive & SD Card & iPod ™(Classic and Nano)

AC Power Cord Connection
To connect the power cord to your PRE50 simply plug female side of the power cord into the power
cord input which is on the rear of the
unit . Then plug the male side of the power cord to an electric
outlet. The AC power cords supplied purposefully have 2 blades and one grounding prong. If your
outlet is not equipped to handle this type of plug, do not attempt to forcefully plug this AC power cord
into the outlet, and do not alter the plug so that it can fit in the outlet. The only course of action you
can take is to find another outlet which is properly equipped to handler a grounded plug or have an
electrician upgrade your electrical outlet.Be sure that the plug is well connected so that it does not
disconnect in the middle of usage. If at any point in time the supplied AC power cord is punctured or
damaged replace it with a new power cord from a local electrician.
NOTE: ONLY PLUG IN THE AC POWER CORD WHILE THE UNIT’S POWER IS OFF AND THE
VOLUME IS TURNED DOWN. TURNING ON THE UNIT WITH THE VOLUME TURNED UP MAY
CAUSE THE UNIT OR ANY SPEAKERS CONNECTED TO IT TO BE DAMAGED. ALWAYS TURN
DOWN THE VOLUME PRIOR TO TURNING OFF THE UNIT.
The active speakers should be connected via the speaker wire outputs on the rear of the PRE50.
Connecting the PRE50 to Active Loudspeakers
Input / Output Connections
Connecting the Signal Source to the PRE50(DVD/MIXER/MP3 etc.)
NOTE: BE SURE NOT TO CONNECT AN AMPLIFIER OR ANY AMPLIFIER SIGNAL INTO THE RCA INPUT
JACKS. AS THIS COULD DAMAGE THE PRE50. ALWAYS MAKE SURE THAT THERE IS ONLY ONE
AMPLIFIER IN THE SIGNAL PATH.
There are also input jacks for USB flash drive and SD card on the front panel of the PRE50 which is
compatible with iPod™(Classic and Nano) via the USB input. Just plug the USB flash driver,SD card or
iPod™(Classic and Nano) into their respective input jacks and set the PRE50 to the corresponding input.
Be sure that the volume of the PRE50
are turned down at first and then slowly raise the volume to prevent
damage the speakers or any of your other equipment.
The unit has three RCA input jacks on the rear of the unit which are designed to receive the signal
directly from your CD,mixer or any of your other sources.To ensure that you have correctly connected
your CD player (other sound sources) to the unit, make sure that the CD player has a RCA cord
coming from its output and that this cord is plugging into the RCA Input on the rear of the PRE50.
NOTE: WHEN MAKING THESE CONNECTIONS THE POWER OF THE PRE50 AND THE SIGNAL SOURCE
SHOULD ALL BE IN THE OFF POSITION WITH THE VOLUME LEVELS TURNED DOWN.
ONCE THE UNITS
ARE ALL POWERED ON, SLOWLY INCREASE THE VOLUME TO AVOID DAMAGING ANY OF YOUR
EQUIPMENT.
Power Cord, MP3 Cable, User Manual, Warranty, Catalog.
Accessories
PRE50
iPod™ & iPhone™ are registered trademarks of Apple Computers, Inc. Apple Computers, Inc. is not endorsing, sponsoring, or otherwise affiliated with this manufacturer.