ETI Sound Systems, INC US-1200 Stereo Amplifier User Manual


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B-52 US Series Professional Power Amplifiers - Instruction Manual
THE BEAUTY OF POWER
US SERIES AMPLIFIERS
NOTE:Matchthepindesignationsprintednext
to the output connectors on rear panel to ensure
proper connections.
9. CIRCUIT BREAKER
The circuit breaker protects the amplifier from faults
attheACsupplyandservesasprotectionwhenthe
amplifier fails.
Ifthecircuitbreakertrips,cuttingACpower
supply to your amplifier, it may indicate a serious
malfunction or failure. Wait for the circuit breaker to
cool before resetting it by simply pressing the reset
knob. If the circuit breaker repeatedly trips, especially
when there is no signal on the inputs or outputs, this
indicatesafailureofyouramplier.DISCONNECT
the power cord from the amplifier immediately and
contact an authorized B-52 Service Center.
There are rare instances when the circuit breaker acts
on a constant heavy overload with a very low imped-
ance load connected to amplifier, protecting your
amplifier against such improper usage. In such cases
you need to check and correct your load (loudspeak-
ers) to provide for the proper load impedance,
and/orreduceoutputsignal.
10. AC INPUT
IECconnectorfortheACpowercable.Connectthe
suppliedheavy-gauge3-pinIECpowercable.
NOTE:NeverdisconnecttheEARTHpinfromthe
ACconnection.Itwilldefeatsafetymeasures
used in your power amplifier and void the
warranty.
US-Series amplifiers feature comprehensive protection
circuitry that protects both the loudspeakers and the
electronics from malfunctioning. The protection is non-
intrusive, sonically transparent and does not affect the
soundunlessthereareextremeconditionsthatacti-
vate the protection circuitry.
ThePROTECTLEDsonthefrontpanelilluminatewhen
the protection is active during the power-up sequence,
when thermal protection is activated, or when there is
amalfunction.WhenthePROTECTLEDsareON,the
amplifier’s outputs are muted.
INITIAL POWER-UP: The protection circuitry will
activate for about two to three seconds from the time
youturnONtheamplier.Thespeakeroutputsare
muted during this period. If the amplifier is operating
normally, the protection circuitry will deactivate and
the amplifier will switch to operation mode.
NOTE:ItisnormalforthePROTECTLEDtofade
graduallyaftertheamplieristurnedOFF.
THERMAL PROTECTION:Excessiveheat-sinktem-
peratures will engage the thermal protection circuitry
to avoid damage to your amplifier. The speaker
outputwillmuteandthePROTECTLEDwillilluminate.
Thermal protection only engages on the channel
whichhastheoverheatingheatsink,excepttheUS-
1200 where both channels will be muted. The thermal
protection will automatically restore to normal opera-
tion mode automatically once the heatsink tempera-
ture drops to a safe level.
NOTE: If the thermal protection constantly
activates, check the impedance of your loud-
speakers and the condition of the air filters on
front of the amplifier. The loudspeakers
impedance must not be lower than what is
specified in this manual for 2-channel and
BRIDGEoperation.8Ohmsand4Ohmsspeaker
loadsperchannel(8Ohmsand16Ohmsin
BRIDGEmode)shouldnottriggerthethermal
protection circuitry if the air access is not
blockedandtheairltersareclean.2Ohms
speakerloadsperchannel(4OhmsinBRIDGE
mode) can cause the thermal protection circuitry
to activate occasionally. If this occurs, decrease
the signal level and consider reconthe speakers
connections to reduce the load on the amplifier
(forexample,donotconnecttoomanyspeakers
in parallel to the same channel).
NOTE:Makesurethereisadequateairaccess
PROTECTION
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