Audio Press Box APB-320 USB-C User manual

APB-320 USB-C
Press Conference Audio Distribution Amplifier
Owner’s manual
English

Always follow the basic precautions listed below to avoid the possibility of serious injury or even death from electrical shock, short-circuiting, damages,
fire or other hazards. These precautions include, but are not limited to, the following:
Always follow the basic precautions listed below to avoid the possibility of physical injury to you or others, or damage to the device or other property.
These precautions include, but are not limited to, the following:
Power supply/Power cord
• Only use the voltage specified as correct for the device. The required voltage is printed
on the name plate of the device.
• Use only the specified AC power adaptor.
• Do not place the power cord near heat sources such as heaters or radiators, and do not
excessively bend or otherwise damage the cord, place heavy objects on it, or place it in a
position where anyone could walk on, trip over, or roll anything over it.
Do not open
• Do not open the device or attempt to disassemble the internal parts or modify them in any
way. The device contains no user-serviceable parts. If it should appear to be malfunctioning,
discontinue use immediately and have it inspected by qualified AudioPressBox service
personnel.
Power supply/Power cord
• Remove the electric plug from the outlet when the device is not to be used for extended
periods of time, or during electrical storms.
• When removing the electric plug from the device or an outlet, always hold the plug itself
and not the cord. Pulling by the cord can damage it.
• To avoid generating unwanted noise, make sure there is 50cm or more between the AC
power adaptor and the device.
• Do not cover or wrap the AC power adaptor with a cloth or blanket.
WARNING
CAUTION
Water warning
• Do not expose the device to rain, use it near water or in damp or wet conditions, or place
containers on it containing liquids which might spill into any openings.
• Never insert or remove an electric plug with wet hands.
If you notice any abnormality
• If the power cord or plug becomes frayed or damaged, or if there is a sudden loss of
sound during use of the device, or if any unusual smells or smoke should appear to be
caused by it, immediately turn off the power switch, disconnect the electric plug from
the outlet, and have the device inspected by qualified AudioPressBox service personnel.
• If this device or the AC power adaptor should be dropped or damaged, immediately turn
off the power switch, disconnect the electric plug from the outlet, and have the device
inspected by qualified AudioPressBox service personnel.
Location
• Before moving the device, remove all connected cables.
• When setting up the device, make sure that the AC outlet you are using is easily
accessible. If some trouble or malfunction occurs, immediately turn off the power switch
and disconnect the plug from the outlet.
• Avoid setting all controls to their maximum. Depending on the condition of the connected
devices, doing so may cause feedback and may damage the speakers.
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Use only the adaptor included with this
AudioPressBox. Use of a different adaptor may
result in equipment damage, overheating, or re.
Be sure to unplug the adaptor from the outlet
when not using AudioPressBox, or when there
are lightning storms in the area.
To avoid generating unwanted noise, make
sure there is 50 cm or more between the
power adaptor and AudioPressBox.
• Do not expose the device to excessive dust or vibrations, or extreme cold or heat (such
as in direct sunlight, near a heater, or in a car during the day) to prevent the possibility of
panel disfiguration or damage to the internal components.
• Do not place the device in an unstable position where it might accidentally fall over.
Connections
• Before connecting the device to other devices, turn off the power for all devices. Before
turning the power on or off for all devices, set all volume levels to minimum.
Handling caution
• When turning on the AC power in your audio system, always turn on the power amplifier
LAST, to avoid speaker damage. When turning the power off, the power amplifier should
be turned off FIRST for the same reason.
CAUTION
• Do not insert your fingers or hands in any gaps or openings on the device.
• Avoid inserting or dropping foreign objects (paper, plastic, metal, etc.) into any gaps or
openings on the device If this happens, turn off the power immediately and unplug the
power cord from the AC outlet. Then have the device inspected by qualified AudioPressBox
service personnel.
• Do not use the device or headphones for a long period of time at a high or uncomfortable
volume level, since this can cause permanent hearing loss. If you experience any hearing
loss or ringing in the ears, consult a physician.
• Do not rest your weight on the device or place heavy objects on it, and avoid use excessive
force on the buttons, switches or connectors.
XLR-type connectors are wired as follows (IEC60268 standard): pin 1: ground, pin 2: hot (+), and pin 3: cold (-).
AudioPressBox cannot be held responsible for damage caused by improper use or modifications to the device, or data that is lost or destroyed.
Always turn the power off when the device is not in use.
The performance of components with moving contacts, such as switches, volume controls, and connectors, deteriorates over time. Consult qualified AudioPressBox service personnel about
replacing defective components.
Illustrations herein are for explanatory purposes only, and may not match actual appearance during operation.
Company names and product names herein are trademarks or registered trademarks of their respective companies.
Specifications and descriptions in this owner’s manual are for information purposes only. AudioPressBox reserves the right to change or modify products or specifications at any time without prior
notice. Since specifications, equipment or options may not be the same in every locale, please check with your AudioPressBox dealer.
3

Dear customer,
Thank you for purchasing the AudioPressBox® APB-320 USB-C.
APB-320 USB-C is a professional portable active press box (Audio Splitter) suitable for both indoor and outdoor press conferences.
It features 2 Analog Mic/Line Inputs, 1 Digital USB-C In & Out, 16 Analog Mic/Line Outputs and 4 Digital USB-C Outputs. Each Analog
Output is independent transformer balanced and isolated. The APB-320 USB-C also includes a rechargeable Battery-pack so it can
run on its own up to 20 hours. All of this is placed in a waterproof, heavy duty Nanuk case.
The package contains
1. AudioPressBox unit.
2. Power supply
3. Manual
4. Test report
Transformer
Individually transformer isolated and
balanced outputs.
Rechargeable batteries
Built-in Li-Ion battery pack with battery
management, 20 hour working time at full
load. 2,5h charging time.
Features:
APB-320 USB-C
4
AC
+
LI-ION
ACCU
PACK
(10 HRS)
TRANSFORMER
16x
Phantom power
It provides 48V phantom power for condenser
microphones.
Mic/Line switch
26dB input PAD. Selection of the input sensitivity –
for devices with microphone or line level outputs.
USB Type C
Digital audio interface for use with video-conference
and for live streaming or digital recording.

APB-320 USB-C
1) XLR Input connector
Plug your microphone or line-level source into this XLR
balanced connector. You can connect any type of
condenser or dynamic microphone here or also output
from a mixing console.
(Pinout: 1-Ground, 2-Hot, 3-Cold).
2) Phantom power switch with indicator
If you are about to use a condenser microphone, turn the
Phantom power switch ON to feed your microphone with
48V. If you use dynamic microphone or microphone with
his own power, you can switch this OFF.
3) Mic/Line Input switch
26dB PAD – input sensitivity selector. If you are using
microphone as an input, this lever should be set to “Mic”
position. If you are using Line input e.g. output from the
mixing console, please set this switch to “Line” position.
In the Line position the Phantom power is automatically
turned OFF.
4) Input Gain knob
You can set the input signal gain depending on the
connected audio source to reach the optimal output
level. You can check the signal level on the Level
indicator (5).
5
8) Battery and Charge Level indicator
When APB is turned ON and is running on battery, the
Battery indicator lights blue. Then the Charge indicator
indicates the actual battery charge level in percent.
When APB is turned ON and plugged to the mains, the
battery is being charged and the Battery indicator is off.
In this case the Charge indicator indicates a charging
process.
9) Mic/Line Output Switch
Output PAD. Each output is switchable between Mic and
Line output level.
Nominal Mic level: -20dBu / Nominal Line level: +6dBu
6
895
4
2
1
7
3
10
11
5) Input Level indicator
Displays the input signal level. To achieve nominal output
level, set the Input gain (4) so that the LED “OK” will be at
least blinking.
6) Power supply connector
Plug the Power adaptor cable here. Please use only
power adaptor supplied with AudioPressBox unit.
7) Power switch
With the power switch, you can turn your
AudioPressBox® ON or OFF. When AudioPressBox® is
turned on, Power indicator lights green.
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13

10) XLR Output connector
Each output is balanced and individually transformer
isolated. It is a balanced XLR connector.
(Pinout: 1-not connected, 2-Hot, 3-Cold)
11) USB-C In & Out connector
USB Type-C connector for Digital audio interface input
and output. This In & Out is for video-conference
connection. (both Analog inputs are transmitted to
video-conference and the video-conference output is
mixed with Analog inputs and sent to all APB Outputs)
12) USB-C Output connector
USB Type-C Digital audio interface output for live
streaming or digital recording. You can connect your
Laptop or Smartphone (with Digital Audio Interface
support) here.
13) QR – Code
Scan this QR code for access to our product support
page with user manual, video guide and user guide.
6

Usage
APB-320 C-USB is designed for use as a distribution audio amplifier for press conferences. It features two analog inputs with input PAD – Mic/ Line
switch, one digital input and output USB interface, sixteen analog audio outputs with individual output level switch – Mic/Line and four digital USB audio outputs.
Analog inputs also feature built-in fixed High Pass Filter set to 120Hz and fixed Compressor with Limiter to ensure high quality output signal without pops
especially when used with microphones. Mic/Line Switch is input PAD (-26dB) for selecting the input sensitivity for microphone or line level inputs. With switch set
to Mic you can connect input signal levels from -56dBu to -16dBu and at Line position from -30dBu to +10dBu. When Mic input level sensitivity is set you can also
turn ON the Phantom power for the microphone – please use this with condenser microphones only. When the input sensitivity is set to Line, the Phantom power is
automatically turned OFF to avoid damage of connected device.
Digital USB Video-Conf. In/ Out is for connection to video-conference where signals from both analog inputs are mixed and transmitted to connected
device and the audio from the video-conference (other side) is mixed with analog inputs and sent to all outputs (analog and also USB). So, the video-conference
attendants can hear speakers connected to AudioPressBox and journalists can record speakers from the room and also speakers attending the videoconference.
USB outputs carries the same audio signal as analog XLR outputs. These outputs can be used for live streaming on social media or for digital recording
on laptop or smartphone which supports digital USB audio interface.
For proper operation and to maintain declared parameters, it is necessary to drive the APB with the correct signal level from Analog or USB Inputs. For
checking the input signal level there is an Input Signal Indicator for each Input. You have proper input signal if the LED “OK” is at least blinking. You can adjust the
right input level for Analog and USB Inputs with dedicated Gain knobň
Each analog XLR output is individually transformer balanced and isolated. You can switch the output level for each output separately to Mic or Line level.
Thanks to the built-in 14,8V 2200mAh Li-Ion battery-pack you can use your press box also on places where is no electric power available. So, no matter if
your conference is indoors or outdoors. Our APB can operate up to 20 hours from the battery-pack on full load. Thanks to the Charge status indicator you always
know what is the actual battery-pack charge. If powered from battery-pack and the LED “LOW” is blinking you should immediately find the power source or the
APB will be soon out of power and will Turn OFF. Charge time for fully discharge battery-pack is around 2,5 hours. Every time the power adaptor is connected, the
battery-pack is charging. No matter if the Power Switch is turned ON or OFF. There is also battery management built in for the battery-pack, so it can’t be
overcharged or deeply discharged. Please never left the unit in discharged state for a longer period of time – it can damage the battery. It is
recommended to charge it before not using it for a longer period.
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Operation
Analog Input:
1. Connect your input device with the XLR cable to the input connector of the APB.
2. Set the Mic/Line switch to desired position – if you use Mic Level input device like a microphone
set it to “Mic”, if you use a line level input device like a mixing console set it to “Line” position.
3. When you are using a condenser microphone, turn the Phantom switch to the “ON” position,
in other cases leave it in “OFF” position.
4. Connect the power adaptor to the Power connector. (If the mains power is available)
5. Turn the APB ON with the Power switch.
6. Adjust the input level with the Gain knob that the LED “OK” is at least blinking.
7. Set your output level – Mic or Line and connect your device – e.g. camera or recorder.
8. You are ready now!
USB Video-Conf. In/ Out:
1. Connect the power adaptor to the Power connector. (If the mains power is available)
2. Turn the APB ON with the Power switch.
3. Connect your laptop with APB via USB-C cable.
4. On your video-conference client choose the USB audio codec as the microphone and speaker
5. Set up the levels – Set the USB input gain on APB that the LED “OK” is at least blinking on the
level meter.
6. Set the desired output level switch for each output as desired – Mic or Line.
7. APB is ready to use!
8

Specifications
9
Audio Press Box APB-320 USB-C
Type 3 in 20 out
Digital:
1
Input section
Inputs 2 analog, 1 digital Input connectors Balanced, XLR
Input Gain Mic: +22/+62 dB Line: -4/+36 dB
Max. input level Mic: -10/-30dBu
Input Impedance Mic: 2,4 kOhm Line: 3,5 kOhm
Phantom Voltage 48V
Output section
Outputs 16 Analog with Line/ MIC level, 4 Digital
Output connectors Balanced, XLR
Nominal Output Level +6dBu
Maximum Output Level +20dBu (no load)
+14dBu (600Ohm)
Output impedance Mic: 220 Ohm Line: 600 Ohm
Transformer isolated outputs Yes (each output)
SNR 86dB
Frequency Response 120Hz to 30kHz/ -3dB
Controls Input section: 26dB PAD, Input gain, Phantom Output section: Power switch, Output PAD
Indicators Input section: Phantom power, Input level
Power Supply 24V DC, 1A external adaptor
Battery Li-Ion, 14,4 V 2200mAh
Battery operation time up to 20hrs
Dimensions (WxHxD) 370x120x300 mm
Weight 5,2 kg
Line: +36/-4dBu
Groups
Analog:
Input connector
Compliant USB Specification
USB Type C
USB 2.0
Input Gain
Supported Sampling Rates
-∞/ +6 dB
32kHz, 44.1kHz, 48kHz
Bit Depth
Interface Powering
16-Bit
Bus Powered*
Charging capability No
*USB Interface is powered from connected USB host device
Output connector USB Type C
Compliant USB SpecificationUSB 2.0
Supported Sampling Rates 8kHz, 11.025kHz, 16kHz, 22.05kHz, 32kHz, 44.1kHz, 48kHz
Bit Depth 16-Bit
Interface Powering Bus Powered*
Charging capability No

Block diagram
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e-mail: [e-mail] | web: www.audiopressbox.com
MediaTech Central Europe, a.s., Drienova 34, 821 02 Braslava, Slovak Republic (EU)
Tel: [phone]