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.
750x – 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/ EFX).
In the LINE position, all front panel controls—including the Aural Enhancer, Overdrive, 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 external effects device in the effects loop, that signal will
also be present when in the LINE position (dictated by the setting of the Ef fects Blend control on your
750x). When in this position, the output level will be af fected 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.
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
Overdrive and SubWave™ effects are not present.
The third position for this switch is the EFX position. In this position, the signal present at the
Balanced Output jack is the same as when in the DIRECT position, with one impor tant exception: the
Overdrive and SubWave™ effects are 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 PA. 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.
The EFX 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 Overdrive and SubWave™
effects, when engaged, without also sending EQ settings that may not be right for the house PA. (or a stu-
dio mixing console). You can always include all of your EQ settings (plus the Overdrive and SubWave) at the
Balanced Output by setting the three-position switch to the LINE position. But thanks to the EFX
position of this switch, it’s not a necessity that you do so just because you want your ef fects present at the
Balanced Output.
Note:
You can still use the Overdrive and SubWave™ Level controls to set the amount of effects pre-
sent at the Balanced Output when in the EFX mode; however, that will also affect the level
present at the speaker outputs. Also, though the Gain control will not affect the level of the “clean”
bass signal present at the Balanced Output when in EFX 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 Effects Level Controls in accordance
with previously mentioned instructions, and the gain structure should fall into place fairly automatically.
10 • 750x OWNER’S MANUAL
