SWR 550x Owner's Manual page 13

The DIRECT + SUB position provides this exact function for the Balanced Output. It always contains the sound of your bass
signal just after the first tube stage, and will also contain the SubWave™ effect when engaged without also sending EQ set-
tings that may not be right for the house P.A. (or a studio mixing console). You can always include all of your EQ settings (plus
the SubWave) at the Balanced Output by setting the three-position switch to the LINE position. But thanks to the DIRECT +
SUB position of this switch, it's not a necessity that you do so just because you want the SubWave™ present at the Balanced
Output.
NOTE: You can still use the SubWave™ Level control to set the amount of sub-octave effect present
at the Balanced Output when in the DIRECT + SUB mode; however, it will also affect the level
present at the speaker outputs as well. Also, though the Gain control will not affect the level of the
"clean" bass signal present at the Balanced Output when in DIRECT + SUB mode, it WILL affect the
level of sub-octave present. This is normal, and occurs because the SubWave™ circuit is located
after the first stage of the preamp tube and is blended back into the signal specifically for this
special mode of the three-position switch. We recommend that you set the Gain and SubWave™
Level controls in accordance with previously mentioned instructions, and the gain structure should fall
into place fairly automatically.
Wiring for the XLR jack at the Balanced Output is as follows:
Pin 1 = ground, Pin 2 = + (plus), Pin 3 = - (minus)
(American Standard)
NOTE: Turn off transients appear at the Balanced Output when the amplifier is shut down. We
recommend that equipment being used in conjunction with the Balanced Output be turned down, off,
or disconnected BEFORE the 550x is turned off.
XLR MODE SWITCH (LINE/DIRECT/DIRECT + SUB)
This three-position switch determines the signal present at the Balanced (XLR) Output jack as described in the section directly
above. In simple terms:
1. Direct = pre-EQ and SubWave™, post-first tube stage
2. Line = post-EQ and SubWave™
3. Direct + Sub = pre-EQ/post-first tube stage blended with SubWave™
Make sure the switch is set either to full left, full right or center to avoid an intermittent condition.
XLR PAD CONTROL
This control sets the level present at the Balanced (XLR) Output. Turning the control counter-clockwise reduces the overall
level, while turning the control clockwise boosts the overall level. It should be noted that turning the control fully counter-clock-
wise to "Min" does not fully defeat the signal. This is normal, as the XLR Pad is designed to provide a range of usable levels to
be sent to a front-of-house or studio mixing console.
XLR GROUND/LIFT SWITCH
Sometimes connecting to certain mixing boards or studio consoles with non-standard XLR wiring can cause a ground loop.
Your 550x has a push-button switch for lifting the ground on the Balanced (XLR) Output. (It affects no other outputs.) Pushing
on the switch will change the mode of operation. When the switch is in the "out" position (default setting from the factory),
ground is on Pin 1 of the Balanced Output jack as normal. When the switch is in the "in" position, the ground is lifted from Pin
1 of this output. If a persistent hum exists after trying both positions of the ground lift, there is probably:
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