Always consult the Owners Manuals first

FX Loop block

From Axe-Fx II Wiki
Jump to: navigation, search

Axe-Fx XL Plus rear.png

Available on which Fractal Audio products

  • Axe-Fx III: no.
  • Axe-Fx II: yes.
  • FX8: no.
  • AX8: yes.

X/Y and channels

  • Axe-Fx III: n/a.
  • Axe-Fx II: no.
  • FX8: n/a.
  • AX8: no.

Using FX Loop as an auxiliary input, auxiliary output or effects send/return loop

FXL enables the effects loop on the Axe-Fx II and AX8. The effects loop is: Input 2/Effects Return and Output 2/Effects Send. You can use this for a Four-Cable-Method (4CM) rig, to connect a second instrument or sound source, to insert a stomp box or rack device, to enable multiple output signals, etc.

Use FXL to:

  • Let a signal from Input 2 enter the grid (Effects Return).
  • Send a signal through Output 2 (Effects Send).

More information in the Owner's Manual.

Setting levels

The Level value is stored per scene in the AX8 and Axe-Fx II. This does not apply to the Axe-Fx III.

Be aware that Input 2 and Output 2 on the Axe-Fx II are set at +4dB line level. On the AX8 these settings are adjustable.

When using FXL as an auxiliary output or effects loop, don't forget there's a physical OUT2 knob on the Axe-Fx II and AX8, which sets the output level.

Parameters table

Parameter Axe-Fx III Axe-Fx II AX8, (FX8: n/a)

Tips and tricks

Route a signal from Input 2 to Output 2

Note: this trick does not work on the AX8, because it requires the Feedback Send/Return blocks.

You can connect an instrument, music player etc. to Input 2, use FXL to let its signal enter the grid, and then send the processed signal to Output 2:

  1. Connect the external gear to Input 2.
  2. Select the correct Input Mode for Input 2 in I/O > Audio.
  3. Add a Feedback Return block to a separate row. Set Mix and Level to 100, to start with.
  4. Add a FXL block after Feedback Return (and effect blocks if desired). Set Level at 100.
  5. Add a Feedback Send block after FXL, with Send at 100.
  6. Turn up Output Level on the front panel to get signal out.

The described routing lets the signal from Input 2 enter the grid through FXL, to be processed by the effect blocks after FXL. FXL's Level parameter sends signal to Feedback Send, which routes the signal back to Feedback Return. From there it enters FXL again, but this time to send the signal to Output 2.

If you want this routing to go to Output 1 as well, connect Feedback Send to the grid's output. WARNING: this will cause extremely loud and high-pitched feedback when nothing is connected to Input 2!

If you want to add signal from Input 1 to Output 2, connect that row to FXL.

Use FXL's stereo channels for two separate mono connections

The FXL block is stereo, so by panning you can have an external loop and still use the FXL's auxiliary output.

Create two effects loops

(Mr Fender): "Put the FX Loop block in front of the amp block and hard pan the signal going into the FX Loop block from that row hard left. In the amp block, set input select to left only. Put a feedback send block before your cab block. Put a feedback return block in another row before the FX loop block and set its balance to hard right. Connect the feedback return block output to the FX Loop block input. The rear Input 2 L and output 2 L jacks are then used for pre-effects and output 2 R is used to feed your power amp and cab on stage. The front panel output 2 knob will control both sides together, so you'll have to play with the levels in the FX loop and feedback blocks to get it all set right."
(Bakerman) "It's possible to use the FX Loop as two mono loops in series, with a certain routing using feedback send/return."


FXL versus Echo Output parameter

ECHO OUTPUT in the I/O menu provides an alternative way. It copies the signal from Output 1 and sends it through Output 2. OUTPUT 2 MODE determines whether it's a stereo or mono signal.

But: if a preset contains the FXL block, the parameter ECHO OUTPUT 2 is always ignored.

Preventing a feedback loop

The Axe-Fx II has a sensor on Input 2. If nothing is connected to Input 2, the effects loop will not run, which prevents feedback loops. source

The AX8 does NOT have this sensor. So in the AX8 you ALWAYS have to put FXL in a branched off (parallel) path, if you use it for a separate output signal.

Avoid feeding Output 1

When FXL is used to send signal to Output 2, it probably should not feed Output 1 as well. In that case do not connect FXL to the grid output. If connecting FXL to the output block cannot be avoided, turn down FXL's level to -80. In the odd case that this does not suffice, set the FXL's and output mixer row's Balance controls oppositely.

More information

  • The Level parameter in the FXL block affects the signal flow to the block AFTER the FXL block, not the signal to OUT 2.
  • If you use FXL as an auxiliary output (OUT 2) and connect it to the end of the grid, turn down its Level to prevent passing signal to OUT 1.
  • How to change FXL from stereo to split.
  • You can use the FXL block to integrate computer effects. Set I/O > USB Digi Source to: OUT 2. source[[category:Sounds]