9
Mode Selection
The three-position, recessed Mode Select switch (located on the rear panel) configures the amplifier for
either Stereo. Parallel or Bridged Mono Mode. Amplifiers are factory-configured for Stereo Mode.
Stereo Mode
In Stereo Mode, both channels operate independently, with their input attenuators controlling their
respective levels. Signal at Channel A's input produces output at Channel A's output while signal at
Channel B's input produces output at Channel B's output.
Absolute minimum nominal load Impedance
for stereo operation Is 4 ohm per channel
. Either the 1/4"(TRS) Input or the XLR Input may be used.
Parallel Mode
When set to Parallel Mode, a signal applied to Channel A's input will be amplified and appear at outputs
of both Channels A&B. Either the 1/4 " (TRS) input or the XLR input on Channel A may be used.
Bridged Mono Mode
Bridged Mono Mode straps both amplifier channels together to make a very powerful, single-channel
monaural amplifier. One channel "pushes" and the other "pulls" equally, doubling the power over that of
either channel alone. Signal is applied to the Channel A input only. Both attenuators are used to control
signal level; in addition, both must be adjusted to the same setting. Only channel A 1/4"(TRS) or XLR input
may be used
.
NOTE:
The channel B Input connectors {XLR and/ or TRS} maybe used to "loop thru" the channel A signal
When in parallel or bridged mono mode.
Use extreme caution when operating the amplifier In Bridged Mono Mode. Never ground either side of
the speaker cable when the amplifier Is in Bridged Mono Mode; both sides are "hot. "If an output patch
panel is used, all connections must be Isolated from each other and from the panel
.
The absolute
minimum nominal load Impedance in the Bridged Mono Mode Is 8 ohms
, which Is the equivalent to
driving both channels separately at 4 ohms. Driving bridged loads of less than the recommended
minimums will activate the IGM circuitry, resulting in a loss of power, and may also lead to a thermal
protect condition. See figures on pages 10 showing output connection information.
Connecting amplifier outputs to oscilloscopes or other test equipment while the
amplifier is in bridged mode may damage both the amplifier and test equipment!
