ETI Sound Systems, INC US-3000 - Manual (Page 16)

THE BEAUTY OF POWER
B-52 US Series Professional Power Amplifiers - Instruction Manual
US SERIES AMPLIFIERS
MOde SeleCT:
STeReO MOde
In STEREO mode, both channels operate independently, with their respective input gain
controls. Signal at the Channel 1 input produces output at Channel 1, while the signal
at Channel 2 input produces output at Channel 2. The minimum load impedance for
STEREO operation is 2 Ohms per channel.
PARAllel MOde
When set to PARALLEL mode, a signal applied to Channel 1’s input will be amplified
and appear at both of the Channel 1 and 2 outputs. The level control knobs will oper-
ate on their respective channels. Channel 2’s input is inactive in the PARALLEL mode.
The PARALLEL mode is well-suited for applications when you need to feed two speakers
with the same signal but each speaker is powered by its own amplifier channel. Mini-
mum load impedance for PARALLEL operation is 2 Ohms per channel.
BRIdged MONO MOde
Bridged mono mode combines both amplifier channels to make a powerful single-chan-
nel amplifier. One channel ”pushes” and the other channel “pulls” the signal equally,
doubling the voltage. When the voltage is doubled, the power is quadrupled if the
same impedance load is used.
In a BRIDGE mode, the signal must be applied to Channel 1’s input only and
Channel 1’s gain control is used to adjust the signal level. The gain control of Channel
2 is not used and input 2 is inactive in BRIDGE mode.
NOTe: Minimum load impedance in BRIDGE mode is 4 Ohms. Connecting a
lower impedance load to the amplifier in the BRIDGE mode may trigger the
protection circuitry. In some instances it may cause severe damage to the amplifier,
which is not covered by the warranty.
WARNINg: MAKE SURE THE IMPEDANCE OF THE SPEAKERS CONNECTED IN
A BRIDGE MODE ARE NOT LOWER THAN SPECIFIED!!!
WARNINg: Do not connect two 4 ohms subwoofers in parallel in BRIDGE mode,
as the total impedance halves in such a parallel connection. The total impedance
will be 2 ohms, and will cause constant overheating and distortion of amplifier. It
will also cause constant triggering of the AC circuit breaker and could damage
your amplifier.
NOTe: In the BRIDGE mode a speaker is connected to both of the channels’
outputs and is not connected to the ground of the amplifier on both ends.
DO NOT ATTEMPT TO GROUND YOUR SPEAKER!
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