SWR Sound 350x XLR Ground/Lift Switch, Tuner Out, Effects Loop for external effects devices

XLR Ground/Lift Switch

Sometimes connecting to certain mixing boards or studio consoles with non-standard XLR wiring can cause a ground loop. Your 350x 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:

1.A bad cable or connection somewhere between your Balanced Output jack and the snake leading to the mixing console;

2.A dirty or miswired A/C socket;

3.Mis-wired or poorly wired A/C in the building;

4.Fluorescent lighting directly above you or in close proximity (especially when using single-coil pickups)

5.A cell phone in your right pocket that’s interacting with the electronics in your bass (don’t laugh, this actually happens!)

But, in the case of a true ground loop, this switch can often times solve the problem.

Tuner Out

The Tuner Out function allows the user to plug their instrument tuner into this jack and “tune up” without having to unplug and go back and forth from amp to tuner. This feature is totally isolated from the rest of the preamp and will function regardless of the settings on the front panel. Being isolated on a side chain avoids loading down of the instrument, which can cause a loss in dynamic range.

To use this feature, connect a shielded patch cord from the Tuner Out jack on your 350x to the input jack on your tuner. Turn the amplifier on and you’re ready to go. If you do not wish to monitor your sound during the tuning process, you may turn down the Master Volume.

Effects Loop (for external effects devices)

As mentioned previously in the “Effects Blend Control” section of the manual, the Effects Blend circuit in your 350x is similar to that used on recording consoles, with the effects loop on a “side chain” to the nor- mal circuit. Unless the Effects Blend control is set to the full “wet” position, you will always get the full sound of your instrument AND get the diversity an external effects unit offers. Use of the effects loop will reduce the noise generated by external effects units (as compared to using the effect between your instru- ment and the input jack, though many people use it in this fashion anyway). This is because the loop is after the preamp gain stages.

The Effects Loop is compatible with most individual or multi-effect external effects devices. Many effects devices on the market have input level adjustments. For instance, some units have a switch that you can set for either -20 dB or +4 dB. In all cases, these should be set for 0 dB (if available) or +4 dB. The level going to your effect is controlled by the Gain control on the front panel.

Note: The Effects Loop is used in conjunction with the Effects Blend control on the front panel. When the Effects Blend Control is in the full counter-clockwise (“DRY”) position, no effects will be heard. This is normal.

Connecting An External Effects Device To The 350x Effects Loop

Obtain two high-quality shielded patch cables, preferably as short as possible. Route them in the most direct way possible. (Running patch cables over the top of the 350x – as with any amplifier – can induce hum in the cables and is not recommended.) Take one cable and connect it from the Effects Send jack on the 350x to the input of your external effects device. Take the second cable and connect it from the out- put of your external effects device to the Effects Return jack on your 350x. To set levels, follow the instructions as previously listed in the “Effects Blend Control” heading under “Front Panel Features.”

And, just so there isn’t any confusion, the Effects Loop has nothing to do with the SubWave™ effect onboard your 350x. It only is used in conjunction with an external effects device.

10 • 350x OWNER’S MANUAL