5
PARALLEL INPUT MODE
What It Is
The "Parallel Input" switches let you operate the amplifier in
parallel mode, delivering the same SIGNAL to both channels
without using a Y-cable. Each channel drivers its own speaker
load, with independent gain, filtering, and clip limiting.
Set switch positions 4, 5, and 6 "ON" to couple the inputs
together. Turn the switches off for stereo, bridge, or other
2-channel modes.
With the inputs in parallel, you can use the other set of input
connectors to carry the SIGNAL to other amps. This is often
called a "daisy-chain."
When To Use It
Parallel the inputs when driving two speakers with one input
SIGNAL (parallel mode) while keeping separate control of
both channels' gain, filtering, and limiting. Use them in
BRIDGE mono mode to patch the SIGNAL to additional
amplifiers through the extra input jacks.
If you are using a balanced SIGNAL, use only
balanced patch cables; even one unbalanced cable will
unbalance the entire SIGNAL chain, possibly causing hum.
Turn off the "parallel Inputs" switches when feeding the amp
two separate SIGNALs.
WHAT ARE THE DIFFERENCES AMONG STEREO,
PARALLEL INPUT, AND BRIDGE MONO MODES?
Stereo Mode
This is the "normal" way of using the amplifier, in which each
channel is fully independent. Separate SIGNALs connect at
the inputs, the gain knobs control their respective channels,
and separate speakers connect to each output.
Examples:
• Two-channel (stereo) playback.
• Two independent mono SIGNALs, such as main and
monitor mixes.
• Bridge operation, with the low frequencies in Channel 1
and the highs in Channel 2.
Parallel Input Mode
This mode is just like Stereo mode, except that the inputs for
Channel 1 and Channel 2 are internally connected together.
A SIGNAL into any input jack will therefore drive both
channels directly. Each channel’s gain control still functions as
usual, and each channel feeds its own speaker load.
You can patch the input SIGNAL on to additional amplifiers
by using any of the remaining input jacks.
Example:
• One mono SIGNAL driving both channels, with
independent gain control each speaker system.
Bridge Mono Mode
This mode combines the full power capabilities of both
channels into a single speaker system. The amplifier internally
re-configures so that both channels operate as a unit. This
delivers double the output voltage, resulting in four times the
peak power and three times the sustained power into a single
8 or 4 ohms speaker load.
Example:
• Driving a single 8-ohm speaker with the combined 4-ohm
power of both channels.
• Driving a single 4-ohm speaker with the combined 2-ohm
power of both channels.
Precautions:
• BRIDGE Mono mode makes it possible to drive thousands
of watts into a single speaker. AC current consumption will
usually be higher. Avoid excessive SIGNAL level, and make
sure the wiring and speaker can handle the power.
• If the load is less than 4 ohms, or prolonged overloads
occur, the amplifier will probably mute for several seconds
during peaks.
• Do not use 2 ohms loads.
FAN COOLING
The fan speed varies automatically to maintain safe internal
temperatures. Keep the front and rear cents clear to allow full
air flow. Hot air exhausts out the front of the amp so it does
not heat the interior of the rack. Make sure that plenty of cool
air can enter the rack, especially if there are other units which
exhaust hot air into it.
BRIDGE
CH-1 OUTPUT
CH-2 OUTPUT
-
+
CH-1
+
-
+
-
CH-2
NOTE
AMPLIFIER SIDE VIEW
Fa
n
WARM AIR EXISTS
COOL AIR ENTERS
