Master Volume Control; Power On/Off Switch; Balanced (Xlr) Output - SWR 550x Owner's Manual

MASTER (VOLUME) CONTROL
The Master (meaning "Master Volume") control adjusts the level being sent to the power amplifier in your 550x–it controls the
overall volume of the unit. Turning the control counter-clockwise reduces the overall level, while turning the control clockwise
boosts the overall level.
Two notes: The Master control never affects the level present at the various audio output jacks on the rear panel–it only
affects the level being sent to the power amplifier, and subsequently, your speaker outputs only. Also, losses caused by exter-
nal effects units can be recovered by increasing the Master control.

POWER ON/OFF SWITCH

This switch turns the complete unit on or off. Setting the switch upwards to the "On" position turns on the unit, and the switch
itself will illuminate in red. Setting the switch downwards to the "Power" position will turn the unit off, and the red light inside the
power switch will turn off as well.
550x - REAR PANEL FEATURES

BALANCED (XLR) OUTPUT

The Balanced XLR out is a true electronically balanced output, suitable for studio and "front-of-house" (live) mixing consoles.
The level present at this output can be adjusted by using the XLR PAD CONTROL (see the "XLR Pad Control" section below
for more details). The signal appearing at the Balanced Output is governed by the setting of the THREE-POSITION XLR
MODE SWITCH located directly below it (LINE/DIRECT/DIRECT + SUB).
In the DIRECT position, the Balanced Output signal comes from directly after the first stage of the specially-selected 12AX7
preamp tube, giving you the sound of your instrument and some added warmth. In other words, it becomes an active TUBE
direct box. In this position, no front panel controls are functional and the SubWave™ is not present.
In the LINE position, all front panel controls–including the Aural Enhancer, SubWave™, and EQ controls–are functional except
the Master control, and the signal is essentially the same as that heard through your speaker system. If you are using an exter-
nal effects device in the effects loop, that signal will also be present when in the LINE position (dictated by the setting of the
Effects Blend control on your 550x). When in this position, the output level will be affected by the Gain control on the front
panel as well as the XLR Pad control. It's worth noting that changing the level of the Gain control will affect the signal present at
your speakers, the Effects Send jack, and the Balanced Output, while the XLR Pad control affects the level present at the
Balanced Output only. For this reason, it's usually better to set your Gain control in accordance with the directions in the "Gain
Control" previously listed in the "Front Panel Features" section of this manual, and to use the XLR Pad control to set the level
specifically for the Balanced Output.
The third position for this switch is the DIRECT + SUB position. In this position, the signal present at the Balanced Output jack is
the same as when in the DIRECT position, with one important exception: the SubWave™ is present. What's the benefit of this
setting?
We've found that most people who use effects pedals prefer to use them in front of the amplifier. In other words, they run their
bass into the effect pedal's input, then from the effect pedal's output into the front of their amplifier. In live applications where
sound reinforcement is required, often times the front-of-house engineer will take a direct signal from the bass itself (via either
a direct box, or the Balanced Output of your amp set to the DIRECT position) and use that signal as the main bass sound to the
house P.A. This way, if the bassist sets the amplifier's EQ controls in a way to his liking, but in a manner not conducive to a
good bass sound for the house P.A., the front-of-house mixing engineer still has a nice, flat bass signal to work with, and then he
can EQ the bass sound for what's best in the room. And, more relevantly, he would still get the sound of any effects pedal that
was placed in front of the amplifier.
12 • 550x