UPDATE 4-6-15: Firmware 18.06 has removed the “Update Amps All Prsts” (Update Amps in All Presets) function mentioned below.

New Axe-Fx II firmware usually bring new features and improvements. It can also change the way Amps are modeled, therefore changing what the controls in the Amp block actually do. For example, in firmware A, the Amp block Bass knob set to 6 may sound “very bassy.” But firmware B might change how that knob works and what it controls, and therefore a value of 7.5 in firmware B may equate to what was a value of 6 in firmware A.

The default settings for Advanced Parameters for different Amp types/models may also be changed with new firmware versions. In a hypothetical example, the default Negative Feedback setting for Amp type 59 Bassguy may be 4.50 in firmware A, but new research and improvements in modeling techniques might suggest that the default setting should instead be 5.20, therefore firmware B would set that default when an Amp is selected for the first time.

Before moving on, it is important to note that generally speaking, if it sounds good to you, it doesn’t matter what the numbers, values, or settings are. Following the previous example, the old Negative Feedback setting was 4.50, but the new default is 5.20. If it sounds and feels good with the 4.50 setting, there is nothing “wrong,” and you aren’t “doing something wrong” by keeping it at 4.50 rather than the new 5.20 default. The parameters are available for us to change to our liking. (Of course, it is possible to change something for the worst and not realize it, so sometimes it’s also best to just stick to the parameters you are familiar with.)

That said, if you do want to use the new suggested defaults in the Amp block, there are a few ways and functions available.

Reset the Amp Block

The first method is to “Reset the Amp Block,” sort of an unofficial function. Note that this will reset Advanced parameters as well as Master Volume, Presence, Depth, “among others.” As described in the Release Notes (RTFRN), this is completed by “deselecting the amp type and then reselecting it, i.e. if the amp type is Deluxe Verb the amp block would be reset by selecting a different model, e.g.Dirty Shirley, and then reselecting Deluxe Verb.”

This method seems best used when you want to reset as many values as possible and start over to create a new tone with the new firmware. The Tone (Bass, Mid, Treble) and Drive (Input Drive, Overdrive) settings are not changed.

Update Amps Defaults

Firmware 15.00 added the function “Update Amps Defaults” – it appears in the front panel Utility menu, Preset page near the bottom of the list. Highlight this menu item and press Enter to execute this function.
This will reset all advanced parameters without changing the Master Volume, Presence, Depth and “other settings” (the additional parameters that are changed when Resetting the Amp Block, described above). This method only updates the Amps in the currently selected preset. It affects both Amp blocks and all XY states.

Update Amps in All Presets (Update Amps All Prsts)

The final method is similar to the previous Update Amps Defaults, but affects all presets currently loaded on the Axe-Fx II. It is also in the Utility, Preset menu and is called “Update Amps All Prsts.” Highlight this menu item and press Enter to execute this function.


New features and parameters available in new firmware will automatically be added and loaded at default settings. There is no need to do any of the above functions to “get” the new features.  

Any previous settings are not affected or changed with a firmware update.  For example, if you previously had the parameter Negative Feedback set to 6.51, loading a new firmware version will not change that Negative Feedback parameter to a default setting of 2.50.