750x Speaker Output Section | SWR Sound manual

Preamp Out

This jack provides another audio output, but it is located later in the signal chain than the Effects Send jack. This signal is post-EQ AND post-effects loop, but still before (pre) the Master Volume control. You should use this jack when using an effects device in the effects loop and wish to achieve:

1.A line level output for use in conjunction with an additional (slave) power amp—such as SWR’s Power

2.An unbalanced output suitable for recording or live mixing board purposes.

Effects Activator Footswitch Jacks

Your 750x comes equipped with the capability for hands-free control of the onboard Overdrive and SubWave™ effects. To achieve this function, locate the dual footswitch included in your 750x packaging. Connect the end with the two 1/4" color-coded phone plugs to the corresponding input jacks on the rear of your 750x as follows:

Red = Overdrive

Blue = Subwave

Note: In some cases, the color code on the Overdrive plug is gray, and the Subwave plug is orange.

Turn the effects on and off by stepping on the desired switch or switches. As you do so, the illuminated switches above the Overdrive and Subwave™ controls on the front panel should alternate on and off, and the chosen effect(s) should engage and disengage accordingly. (Just so you know, we left the footswitch jacks independent of each other just in case you want to use your own separate footswitches and locate them in different positions on your custom pedalboard.)

Note: The type of switches contained inside the footswitch chassis are both momentary, normally open. Also, if you connect the footswitch to the unit while the unit is on, the effects may engage. This is normal.

Cooling Fan & Fan Mode Switch

The power amp in your 750x is cooled by two methods: a) an (internal) extruded aluminum heatsink; b) a fan. Be sure to leave at least a 1/2" clearance between the vent on the top of your 750x and anything you wish to put on top of it. This will allow for the heat generated by internal components to escape.

You have complete operational control of the fan via the Fan Mode Switch. Setting the Fan Mode Switch to the “On” position activates the internal cooling fan. Setting the switch to the “Off” position deactivates the cooling fan, regardless of the internal temperature of the unit. For this reason, it is recommended that the Fan Mode Switch be set to the “On” position for the majority of the time that the amplifier is in operation.

Note: It is normal for the cooling fan to be audible at low levels. We recommend deactivating the fan only in situations where the noise floor is so low that normal fan noise might be noticeable or distracting, such as recording situations where a microphone is used in close proximity to the unit.

750x – SPEAKER OUTPUT SECTION

This section of the manual will deal with the proper connection of speaker cabinets to the power amplifier in the 750x. Some of this ground has already been covered in the “Getting Started—Connecting Your Speaker Cabinets” section in the beginning of the manual. This is meant to supplement that section and provide information in greater detail, as power amplifiers, impedance and speaker cabinets are all crucial in deter- mining how best to operate your new 750x.

How Impedance Affects Power Ratings

People often have questions about impedance. What is it? The root of the word “impedance” is the verb “impede,” which means to block or resist. That’s what impedance is—resistance to power.

Solid-state power amps do not have a pre-determined impedance. They deliver power at whatever imped- ance the speaker cabinet tells it to. That’s why you hear the term “slave amp”—amplifiers only do what they’re told. So if someone tells you that they have a “4 ohm power amp,” their terminology and under- standing of the concept is way off the mark.

750x OWNER’S MANUAL • 13