AM4 firmware release notes

1.02 - released: 2026, Jan 15

New Features & Improvements​

The AM4 is now up to date with Axe-Fx III firmware release 31.03.

New Deluxe 6G3 amp model based on the bright channel of a 6G3 “Brownface” Deluxe.

New Citrus Juicer compressor model, based on the Dan Armstrong Orange Squeezer™. The original pedal has a single knob, but the model adds additional parameters for extended flexibility. On the original, the ratio and threshold vary with the specific components used and the internal bias trim. As a starting point, set Threshold to –26.0 dB and Compression to 8.0, then adjust to taste.

The new Half-Wave detector type used by this model is also available for other compressor types, offering different attack and release behavior and a slightly grittier character.

Improved Amp block preamp modeling for more accurate response when the amp is driven harder—for example, when using a boost or overdrive.

Improved Amp block phase inverter modeling - Went through every model with a fine-toothed comb and adjusted power amp and phase inverter parameters as needed to reflect new modeling.

Analog Bypass is now available on the AM4. When engaged, the signal passes directly from input to output with no digital conversion, processing, or latency. Analog Bypass can be controlled via a footswitch, MIDI, or an external pedal/switch, and it can also be set to engage automatically when all four blocks are bypassed by using SETUP > Global Settings > Automatic AM4 Bypass.

Improved “Dwell” in spring reverb types.

The default startup mode is now Preset Mode instead of FX Mode.

New warning when an external S/PDIF clock is detected at a frequency other than 48 kHz.

New “USB 3/4 Record Source” option – Allows USB channels 3/4 to be set to NONE so the input DI signal is not sent to the computer. This option is provided specifically for use with software such as OBS and other streaming or recording applications that cannot select individual USB inputs and instead listen to all available USB channels, which could otherwise result in the DI signal being unintentionally blended with the processed AM4 output.

AM4 is now supported in Cab-Lab version 1.01.01 or newer.

Fixes​

Corrected the order of Treble Gain / Normal Gain in some amps.

Fixed the expert Cab Preamp VU meter.

Fixed an issue that would cause Preamp Tube Type to not update when selecting certain models/modes.

Fixed incorrect default DynaCabs for Class-A 30W and Band Commander.

The hardware now follows along perfectly when the amp type is changed in AM4-Edit.

Changing the Amp Type from AM4-Edit does not trigger a refresh of the control UI.

Very long preset names no longer cause a problem for the preset picker page.

Removed non-working stereo spread control from mono spring reverbs.

Reset System parameters now correctly sets SPDIF In Level to 0.00.

Fixed interaction of metronome and FX bypass remote switching.

Fixed an issue caused by certain diode settings in the Drive block.

Small fixes to the Deluxe Tweed, Band Commander, and Herbie amp models, and Pi Fuzz drive types.

Corrected the level for USB 3/4 for recording a DI.

Corrected an issue that could occur when changing amp type while DynaCabs were loading.

Fixed Amp GEQ display when it is toggled on/off by a modifier.

Speaker Impedance Curves are now auto-set correctly when changing channels in all cases.

Various other fixes and improvements.

1.01 - released: 2025 Nov 24

Initial firmware release on the first shipped units.