Instruction manual

THE BEAUTY OF POWER
B-52 US Series Professional Power Amplifiers - Instruction Manual
US SERIES AMPLIFIERS
POWER
PROTECT
CLIP
-10dB
-20dB
SIGNAL
PROTECT
CLIP
-10dB
-20dB
SIGNAL
BRIDGE PARALLEL
CHANNEL 1
0
1
2
3
4
5
6
7
8
9
10
11
12
13
15
17
19
22
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54
CHANNEL 2
0
1
2
3
4
5
6
7
8
9
10
11
12
13
15
17
19
22
29
54
POWER AMPLIFIER
US-SERIES
FRONT PANEL CONTROLS
1
12 2
Opposite page
1. RACK MOUNTING POINTS
Points to bolt your amplifier into a rack.
2. AIR VENTS
US-Series amplifiers are cooled by two rear-mounted
fans (US-1200 has one fan) and open cell foam filters
mounted behind the front vents.
CAUTION: Never block the front or rear vents
and keep them clean at all times.
NOTE: Periodically clean the foam filters using a
vacuum cleaner to avoid dust from blocking the
vents. If the filters become too dusty, it may
decrease your amplifier’s ability to dissipate
and remove heat efficiently. If the filters become
 toodustyandtoodifculttocleanexternally,you
can access the filters and remove them for
cleaning. Refer to the cleaning procedure later
in this manual.
3. BLUE ILLUMINATED STRIPS
These two blue illuminated strips glow when your
amplieristurnedON.
NOTE:YoucandimtheblueLEDstripsorturn
 themoffwhenconvenientinaxedinstallation.
4. CHANNEL 1 AND CHANNEL 2
LEVEL CONTROLS
Use these 21-position detented controls to adjust the
output levels of Channel 1 and Channel 2. When
theLEVELcontrolsaresetfullycounter-clockwise,the
signal is attenuated by more than 80dB (marked -∞).
WhentheLEVELcontrolsaresetfullyclockwise,the
signalisampliedwithmaximumgain.Whenthe
LEVELissetfullyclockwise,theamplierproduces
itsratedoutputpowerata4Ohmloadwith+4dBu
(1.23Vrms)signalappliedtotheinputs.Alldetents
are marked in dBs showing the attenuation of
the output signal with reference to the fully
clockwise position.
NOTE:InPARALLELMONOmode,bothofthe
 Channel1andChannel2LEVELcontrolsare
used to adjust the signal level for their respective
channels. The signal should be routed only to
the Channel 1 input in this mode.
NOTE:InBRIDGEDMONOmode,onlythe
 Channel1LEVELcontrolisusedtoadjustthe
signal level. The signal should be routed only to
Channel 1’s input in this mode.
5. SIGNAL Indicators
ThesegreenLEDswillilluminateindicatingthata
signal is being received through the input and that
thesignalisbeingamplied.TherearethreeLEDson
eachchannel:SIGNAL,-20dBand-10dB.
6. CLIP Indicators
TheseredLEDswillilluminateattheclipping
threshold.IftheCLIPLEDslightfrequently,youare
overloading the amplifier, causing gross distortions
on the outputs. Heavy clipping is bad for both your
speakers and amplifiers and should be avoided.
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