Citation:
Axe-Fx II Quantum Firmware Release Notes
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2.00
Improved tube modeling. New algorithms uses more accurate plate current formulas based on actual measurements rather than theoretical values. This results in smoother, thicker distortion and better dynamic response.
Improved power supply modeling. New algorithms improve sag and feel. For convenience the virtual power supply (B+) can now be monitored on the PWR DYN tab of the amp block. When the Supply Sag control is selected the gain reduction meter will display the supply voltage in dB relative to the idle voltage.
Improved cathode bias algorithm for “Class-A” amp models (i.e. Class-A 30W, AC-20 Dlx, etc). In conjunction with this the Cathode Squish parameter has been repurposed as “Cathode Bias” and controls the value of a virtual cathode resistor. A value of 50% is “optimum” and biases the power tubes at true Class A operation (neglecting any bias shifting due to supply sag, screen droop, etc.). Values greater than 50% increase the resistance and therefore bias the power tubes “colder”. Values less than 50% bias the tubes beyond Class A. In a real amp this would probably destroy the tubes but that limitation does not exist in our virtual amp. Most real amps of this type actually operate far below Class A and the default values for the models will reflect this. Note that the Power Tube Bias value should be set to 1.00 for these amp types (since that parameter controls the grid voltage and the grid voltage is at a maximum in these types of amps). Existing presets will be automatically updated with new default Cathode Bias and Power Tube Bias values.
Improved Phaser block CPU usage.
Improved Plexi “Jump” models to account for interaction between Drive controls.
Renamed Plexi 50W High amp model to “Plexi 50W Hi 1” (see below).
Added “Plexi Hi 2” amp model which is similar to Plexi 50W Hi 1 except the second triode stage has a 0.68uF cathode bypass capacitor. The second bypass capacitor was added in the early 70’s and gives a slightly brighter tone.
Added “Plexi 100W 1970” based on a 1970 Marshall 1959SLP 100. This particular amp has a darker, smoother sound than earlier Plexis.
Added “Ruby Rocket” amp model based on a Paul Ruby Rocket with the Bright switch in the down position. The existing model has been renamed “Ruby Rocket Brt” to reflect the state of the Bright switch being in the up position.
Added “AC-20 12AX7 B” amp model based on an AC-20 Deluxe with the rear switch set to 12AX7 and the Bass/Treble switch set to Bass. The existing models have been renamed AC-20 EF86 B, AC-20 EF86 T, and AC-20 12AX7 T.
Added “Spawn Nitrous 1” amp model based on the OD-1 mode of a Splawn Nitro with KT-88 power tubes.
Fixed Spawn Nitrous model broken by earlier firmware update. If you are using this model in your presets you should reset the model by deselecting and reselecting the amp type. This model has been renamed “Spawn Nitrous 2” to indicate that it is the OD-2 mode (see above).
NOTE: This firmware represents a significant update in the amp modeling and the amp models themselves. Many models have been redone. Although care was taken to ensure as much compatibility with existing presets as possible, your presets may be altered.
