Audio Press Box APB-448 SB User manual

APB-448 SB
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,
re 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speciedascorrectforthedevice.Therequiredvoltageisprinted
onthenameplateofthedevice.
• Useonlythespecied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qualied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qualied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qualied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.
2

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disguration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amplier
LAST,toavoidspeakerdamage.Whenturningthepoweroff,thepowerampliershould
beturnedoffFIRSTforthesamereason.
CAUTION
• Donotinsertyourngers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qualied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modications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qualied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.
Specicationsanddescriptionsinthisowner’smanualareforinformationpurposesonly.AudioPressBoxreservestherighttochangeormodifyproductsorspecicationsatanytimewithoutprior
notice.Sincespecications,equipmentoroptionsmaynotbethesameineverylocale,pleasecheckwithyourAudioPressBoxdealer.
3

Dearcustomer,
Thank you for purchasing AudioPressBox® APB-448 SB, the most sophisticated press conference distribution amplier. Signal from four
lectern’smicrophonesorlineinputs(i.e.mixingconsole)isdistributedtoindependentmicrophone/lineoutputsusedbymultiplejournalists,TV
Cameraoperators,audiorecordersandreportersatthesametime.Nomorehasslewiththemultiplemicrophonesonthetableordisturbing
late-comingreporters.WithAudioPressBox®youaresetinaminutewithprovidingtheperfectsignaltoeveryreporter!
Unpacking your AudioPressBox®
YourAudioPressBox®comestoyoupackagedinthetransferboxwiththellingmaterialinusedtoavoidanydamagecausedbytransport.
Inthepackage,youshouldnd:
1) Powersupplywithmainscable
2) AudioPressBox®
3) Thismanual
Pleasebecarefulwhileunpackingallthecomponentsfromoriginalpackaging.
Using your AudioPressBox®
UsingeveryAudioPressBox®modelissimpleanditcanbepresentedin4simplesteps:
1) Plugyourmicrophonein
2) Setyourlevels
3) Connectyouroutputs/extenders
4) StartusingyourAudioPressBox®byprovidingperfectlyprocessedsignaltoevery
 recipient,whoconnectshisdeviceintotheoutputsection.
APB-448SB
4

APB-448SB-Frontpanel(Inputsection)
Besuretoleavethisswitchoff()ifyoudonot
needphantompower.
Whentuningtheswitchon(),besurethatonlycondenser
mics are connected to the XLR input. Devices other than
condensermicsmaybedamagedifconnectedtothephantom
powersupply.Note,however,that theswitchmaybe lefton
whenconnectingtobalanceddynamicmicrophones.
Toavoiddamagetospeakers,besuretoturnoffampliers(or
poweredspeakers)beforeturningthisswitchonoroff.Wealso
recommendthatyouturnalloutputcontrolstotheirminimum
settingsbeforeoperatingtheswitchtoavoidtheriskofloud
noisesthatcouldcausehearinglossordevicedamage.
1) Input XLR microphone/line connector
Input your microphone or line-level source into this
XLR balanced connector. You can connect any type of
condensereitherdynamicmicrophonehere.
(1:Ground;2:Hot,3:Cold).
2) Phantom power indicator
If the Phantom power is on, this is indicated with solid
redlight.
3) +48V button
Ifyouareabouttousecondensermicrophone,turnPhantom
powerswitchONtofeedyourmicrophonewith24/48V.Ifyou
usedynamicmicrophoneormicrophonewithhisownpower,
youcanswitchthisOFF.
4) PAD button
If you are using microphone as an input, this button
shouldbesetto“Off”position.Ifyouareusinginputfrom
themixingconsoleorCDplayer,pleasesetthisswitchto
“On”position.
5) Input gain level knob
Afterconnectingyourmicrophone,youcansettheinput
leveltoreachperfectunderstandingoflectern’sspeech.
6) 160 Switch (High Pass Filter)
This button helps to avoid distributing low-end rumble
like a microphone handling noise or pops. You have 2
options–fullrangeor160Hzlow-cutfrequency.Theone
youchoosedependsonthesound,youwanttolterout.
CAUTION
5
Clip
6
0
-6
-30
3
6
12
18
A
+
B
A B
PFL
PAD +48V HPF COMP
Out to
Signal GR[dB]
Clip
6
0
-6
-30
3
6
12
18
A
+
B
A B
PFL
PAD +48V HPF COMP
Out to
Signal GR[dB]
Clip
6
0
-6
-30
3
6
12
18
A
+
B
A B
PFL
PAD +48V HPF COMP
Out to
Signal GR[dB]
Clip
6
0
-6
-30
3
6
12
18
A
+
B
A B
PFL
PAD +48V HPF COMP
Out to
Signal GR[dB] A B
Osc AFL AFL
Phones
Volume
APB-448SB
Charge
100%
50%
25% ON
OFF
Low
Battery Power
[dB]
ON
OFF
Hold
5s
- 12 -
- 6 -
- 0 -
- -6 -
- -12 -
- -24 -
- -48 -
[dB]
Output
5
98 10 7
1161
2
4
3
25 1713
161412 15 19 18

label the outputs in the output extender with names of
thelecternsorgroupsandreporterseasilydecidewhich
groupoutputtheywanttouse.
12) Test signal oscillator operation switch
To test signal level, which is coming to the outputs,
you can switch this Test 1kHz sine signal oscillator on.
Afterrecipientssetthe levelsin theirrecordingdevices,
you should switch this function OFF. When compressor
switchissettoON,outputsignallevelwon’texceedthis
maximumoutputlevel.
13) Global group output level indicators
You can check output levels of each group individually
herein7-segmentlevelindicationbar.
14) AFL button
Forbettercheckyourlevels,youcanisolateoutputfrom
each group to your headphones.  You can check the
output levels of each group by hearing. Just push the
buttonandyouwillhearoutputfromparticulargroup.
15) Output level knobs
Set output levels to each group individually and adjust
them that they will not reach the higher levels (6 – 12
values) constantly. You can check the levels with the
headphones.
16) Headphones output connector
If you want to monitor the output by your headphones,
youcanplugthemtothisconnector(6.3TRS/Jackstereo
connector).
Youcanchecktheresultwithyourheadphonespluggedin.
7) Compressor/Limiter operation button
To provide perfect output signal without clipping or
distortion, you can switch the Comp button ON. If you
switch this OFF, signal in output could contain signal
clippingordistortion.
8) PFL button
Tocheckyourlevelsonlyforoneinput,pushthisbutton
and you can see the level of output for corresponding
input.Youcaneasilyseeifallmicrophoneshavethegood
outputlevelsandidentify,ifsomeofthemicrophonesare
tooloudortoosilentintheoutput.
9) Microphone level indicator bar
You can visually monitor the level of each microphone
outputsignalin5-segmentoutputindicatorbarwithsignal
clipLED.Ifthisredlightisashing,youshouldreducethe
gainofthemicrophone.
10) Gain Reduction indicator bar
IfCompswitchissettoON,youcanvisuallymonitorthe
levelofGainreductiononthis4-segmentindicatorbar.
11) Routing switch
Eachmicrophonecouldberoutedto2separatedgroups
ortobothgroupsatthesametime.Thisisuseful,ifyou
havetwo(orfour)lecternsand youwanttoroutesignal
from each microphone (or group of 2 microphones) to
separatedtracks.Reporterscanedittherecordingeasily,
iftheyhave bothlecterns onseparated tracks. You can
17) Headphones output level knob
Ifyouhaveyourheadphonespluggedin,youcanadjust
thelevelofmonitoringtheoutputbyturningthisknobto
set your comfort hearing level. Please be careful when
setting the levels, too high monitoring volumes can
damageyourhearingability!
18) Power ON indicator
WhenAudioPressBox®isturnedon,thisindicatorlightsup.
19) Power switch
Withthepowerswitch,youcanturnyourAudioPressBox®
ONorOFF.
6

APB-448SB-Rearpanel
21) XLR connectors for output extenders
Withtheseconnectorsyoucanconnectextenders
(APB-024R-EX,APB-008OW,APB-008IW,APB-P112SB)
toprovideoutputstoreporters
20) Power supply connector
PlugthemainscabletoAudioPressBox®here.
7
DC 24V A A B B
22
20 21

APB-448SB-Rearpanel
23) Mic/Line level select switch
YoucansetifyouwanttogetMic(-20dBu)orLine(+6dBu)
levelfromindividualoutput
22) Group A Mic/Line Outputs 1-24 + Group B Mic/
Line Outputs 1-24
Mic level output XLR connectors – every output is
individuallytransformerisolated.
8
APB-448SB
Out A
Balanced Isolated Outputs
Mic Level -20dBu
Line Level +6dBu
Out B
Balanced Isolated Outputs
Mic Level -20dBu
Line Level +6dBu
1 2 3 4 5 6 7 8 9 10 11 12
13 14 15 16 17 18 19 20 21 22 23 24
Mic Line Mic Line Mic Line Mic Line
Mic Line Mic Line Mic Line Mic Line
Mic Line Mic Line Mic Line Mic Line
Mic Line Mic Line Mic Line Mic Line
Mic Line Mic Line Mic Line Mic Line
Mic Line Mic Line Mic Line Mic Line
1 2 3 4 5 6 7 8 9 10 11 12
13 14 15 16 17 18 19 20 21 22 23 24
Mic Line Mic Line Mic Line Mic Line
Mic Line Mic Line Mic Line Mic Line
Mic Line Mic Line Mic Line Mic Line
Mic Line Mic Line Mic Line Mic Line
Mic Line Mic Line Mic Line Mic Line
Mic Line Mic Line Mic Line Mic Line
22 23

Get your AudioPressBox® operational:
1. PlugmainscabletoconnectoroftheAudioPressBox®(20).
2. TurnAudioPressBox®onbyswitchingPowerswitch(19)ON.
3. PlugyourmicrophoneintoinputXLRconnector(1).
4. Ifyouareusingcondensermicrophone,switchPhantompower(2)ON.
5. SwitchComp(7)ON
6. SpeaktothemicrophonesandadjusttheInputgain(5)leveltogetvisualconrmationonmicrophonesignallevelindicator(9)
 asyouspeak,thisindicatorwilllightupcontinuously.
7. Setroutingpathforeachmicrophone(11)
8. Ifyouwanttohearyouroutputsignal,plugyourheadphones(with6.3mmTRSconnector)toheadphoneconnector(16)andadjustmonitoringlevel(17)tolistentotheoutput.
9. Recipientscanplugtheirrecordingdevicestospeciedoutputsintheextenders.
10. Youarereadytogo!
Good to know:
What are compressor and limiter?
Theseelementsautomaticallycontrolyoursignalandprovidethebestsignalconditionforeveryoutput.Youwillgetperfectsignalwithoutclippingordistortion.Youcanswitchthis
elementonoroffforeachinputdependingyourneeds.
What is the signal generator for?
Asignalgenerator,alsocalledatestsignalgeneratorisanelectronicdevicedesignedtoproducesinesignal-frequencyof1kHz,whichcanhelptosetyourlevelscorrectly.
9

Specications
10
Audio Press Box APB-448SB
Type 4 in 48
Groups 2
Input section
Inputs 4
Input connectors Balanced, XLR
Input Gain MIC LINE
+22/+62 dB -4/+36 dB
Max. input level Limiter ON Limiter OFF
MIC: -10/-30dBu MIC: -2/-42dBu
LINE: +36/-4dBu LINE: +24/-16dBu
Phantom Voltage 48V
Input Impedance MIC: 2,4 kOhm LINE: 3,5 kOhm
Output section
Outputs 48 MIC/LINE:
24x Output A (transformer isolated, balanced, XLR connector)
24x Output B (transformer isolated, balanced, XLR connector)
Extender:
2x Bus A (balanced, XLR connector)
2x Bus B (balanced, XLR connector)
Nominal Output Level +6dBu
Maximum Output Level +20dBu (no load)
+14dBu (600kOhm)
Output impedance MIC: 220 Ohm LINE: 600 Ohm
SNR 86dB
Frequency Response 20/160Hz (filter) to 30kHz/-1dB

Jacklist
InputandOutputJacks Polarities Congurations
MICINPUT
Pin1:Ground
Pin2:Hot(+)
Pin3:Cold(–)
11
Controls Input section: Output section:
26dB PAD, Input gain, Phantom,
High-pass filter, Compressor, PFL,
routing switch
Oscillator, Output level for Bus A and
Bus B, AFL for Bus A and Bus B,
Phones level, Power, Output PAD
Indicators Input section: Output section:
Input Clip, Phantom power, Input level,
Gain reduction, PFL
Output level for Bus A and Bus B, Oscillator, Power, Battery status
Power Supply 24V DC, 300mA external adaptor
Battery Li-Ion, 14,4V 2200mAh (optional)
Battery Operation Time min. 6hrs
Dimensions (WxHxD) 430x260x100mm
Weight 6,8kg

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Blockdiagram
12

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