Owner`s manual

Abox in detail
8
8.4 Ground Lift
ThisswitchtacklesthegroundloopissueencounteredwhenAMPandPAare
simultaneouslyconnectedtotheAbox.
IfyouexerienceaHum,setthisswitchtoLIFTposition.
8.5 LEVEL AMP
TheLEVELAMPknoballowsyoutocontroltheoutputsignallevelthatisdi-
rectedintoyourAMPviatheunbalancedJACK.

8.6 LEVEL PA
TheLEVELPAknoballowsyoutocontroltheoutputsignallevelconnectedto
yourPA/MIXERviaXLRbalancedcable.
9 Acoustic Box in practice
Thissectionwillguideyoutodoyoursoundcheckinafewminutesandobtain
thebestsoundresultwiththepreamp
Beforesupplyingpowertothepreamp,makesurethatthemainsvoltageis
properlyselcted(seepage5)
9.1 Preparation
TurnontheAboxusingthepowerswitchandmutetheoutputusingthemute
switch(positionup)ontheAbox.
Connectallyourinputs(micand/orpiezo)andoutputconnections(PAand/
orAMP.
Verifyingusingthelightmonitorsthatthepickup/micareproducingasignalin
thechannel/s
PlacetheAMPandPALEVELknobsat12o’clockandsilencetheLEVELknobs
ofbothinputchannels
9.2 Using condenser/membrane mic and piezo
Thissectioncontainssomenetuningtipsforthosewhousecondensermic
(DPA4099,ATM350,AKGC414,Neumannu87,etc..)ordynamicmic(SHURE
SM57,SM58,etc..)incombinationwithpiezopickup.
IncreasetheLEVELofCH1tillyouhaveagoodaudiblevolume.
SettheMID’s(CH1)knobto15o’clockandsearchwiththecorresponding
frequency(FREQ)knobforthemostunpleasentfrequency.Ifyouareusinga
piezoitshouldbebetween12and15o’clock.Onceyouarethere,usethe
MIDknobtoremoveituntillthesoundismorenatural.Inmostofthecases
placingtheMIDknobat9o’clockwilldothejob.
Beforeaddingthemicsignal,deactivatethenotchlter,thelowpasslterand
thephaseswitchCH2bysettingthecorrespondingswitchesindownposition.
GentlyincreasetheLevelofchannel2tillthelevelofthesecondchannelis
addingthebottomend.UsethephaseswichCH2toadjustthephaseshift
betweenthetwochanelsifrequired.
Ifyouexperiencelowfrequencyresonance/feedbackturnonthenotchand
tuneituntillthelowfrequencyresononace/feedbackisremoved.
UsetheLowPassFiltertoremove6dBsomeofthemidshighfromthemic
channel.Thatmaybeusefullifyouareperformingwithadrummer.
AdjustyourLOW-MIDS-HIGHformthetonecontroloftheblendedsignalto
improvethesoundquality.
9.3 Using AKG C411 and piezo
IncreasetheLevelofChannel1tillyouhaveagoodaudiblevolume.
SettheMID’s(CH1)knobto15o’clockandsearchwiththecorresponding
frequency(FREQ)knobforthemostunpleasentfrequency.Ifyouareusinga
piezoitshouldbebetween12and15o’clock.Onceyouarethere,usethe
MIDknobtoremoveituntillthesoundismorenatural.Inmostcasesplacing
theMIDknobat9o’clockwilldothejob.BeforeaddingtheAKGC411signal
fromCH2,deactivatetheNotchandactivatethelowpass.