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 750x 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 750x—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 750x to the input of your external effects device. Take the second cable and connect it from the output of your external effects device to the Effects Return jack on your 750x. 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 Overdrive or SubWave™ effects onboard your 750x. It is used only in conjunction with an external effects device.
Effects Send
This jack’s primary function is to send a post-EQ-and-Overdrive/SubWave™ signal to an external effects device for use in the 750x Effects Loop. However, it can also be used as:
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.
The output impedance of the Effects Send jack is 100 Ohms.
Effects Receive
This jack’s primary function is to complete the Effects Loop circuit by routing the post-external-effects device signal back into the power amp of the 750x, where it can be blended back in with the original signal by using the Effects Blend control on the front panel. However, it can also be used as:
1.A power amp input jack. If, for some reason, you wished to bypass the entire front end and use the 750x strictly as a power amp, you could take the output of whatever line-level audio source you wished and connect it to this jack. Then, set the Effects Blend control to the full clockwise (“WET”) position.
Use the Master control to set the overall level, and your 750x is now a power amp only.
2.An input for pre-recorded music, for playing along and practicing purposes. To accomplish this, insert a CD player or other sound source into the Effects Receive jack. (It must be a MONO 1/4" plug that goes into this input, so you’ll have to use a stereo-to-mono cable adapter of some kind.) You can adjust the level of recorded music versus the “live” sound of your instrument by using both the Effects Blend control (the more clockwise the control, the more pre-recorded music signal you’ll hear) and the volume control of your CD (or other) audio source. The mixed sound will be heard through your speakers. Besides pre-recorded music, this is also an excellent way to practice along with a drum machine.
Input impedance of the Effects Receive jack is 27k Ohms minimum.
Note: Inserting a plug into the Effects Receive jack activates the Effects Blend control. The control receives this command through the ground created by the phone plug making contact with the jack. The plug must be a mono plug (tip and ground). If you have a stereo plug only, it will be nec- essary to tie the ring and the ground together.