40
Doc Q7.0
Amp Preamp Page (“PRE”)
5.1.2
INPUT DRIVE
– (aka “Drive”) sets the amount of preamp gain/distortion. Used in conjunction with the
MASTER
(see below),
INPUT DRIVE
determines whether the sound will be clean, slightly broken up,
moderately overdriven, or completely distorted.
Our modeling faithfully reproduces the sound of the treble peaker circuit on the
INPUT DRIVE
control found on
many amps. This can be heard as the low frequencies are reduced more than the highs when the
INPUT DRIVE
is turned down (and vice versa).
For amps that have no
MASTER VOLUME
, the
INPUT DRIVE
also functions as the amp’s VOLUME control.
NOTE: Amp models that simulate “jumpering” the inputs of a 4-hole amplifier (e.g. PLEXI 50W JUMP, HIPOWER JUMPED, etc.)
have separate TREBLE DRIVE and NORMAL DRIVE controls, which behave as Controls for their respective channels.
OVERDRIVE
– The
OVERDRIVE
control appears only for certain amp types. Note that
DRIVE
and
OVERDRIVE
are applied to the appropriate points in the circuit for the amp being modeled, i.e. prior to the last triode
stage or prior to the third triode.
INPUT TRIM
– Amps without
OVERDRIVE
will display the
INPUT TRIM
instead. This allows you to adjust for
more or less preamp gain than the actual circuit being modeled. This is different than the Input
DRIVE
control
because
DRIVE
interacts with the surrounding circuitry, changing frequency response as it is varied.
BOOST
–
Toggles an additional 12 dB of gain at the input of the amp sim. (For amp types that have an
OVERDRIVE
control (see above,)
BOOST
appears only on the ADVANCED page.)
BASS, MID, TREBLE
–
While other modelers use simple filters to approximate amp tone controls, the Axe-
Fx II replicates exactly the frequency and phase response of a classic passive tonestack. In most instances,
matching knob settings between the Axe-Fx and the original amp will recreate the same tones.
Some of the original amps simulated on the Axe-Fx II do not have all of the tone controls offered on our
models. Some, for example, have no mid control. To faithfully simulate the configuration of the original, set
any superfluous controls to noon (or “0.00” if you are using the “ACTIVE” tonestack type; see below). Of
course, you may still adjust to achieve tones the original amp does not have.
Extreme tone and high gain settings can cause pickup squealing or excessive noise. This is especially true
with the
TONESTACK TYPE
(p. 54) set to “ACTIVE.”
CUT SWITCH
–
(engaged by a switch beneath
BASS
) reduces the amount of low frequencies into the amp
simulation. This can be used to achieve a “tighter” tone or to reduce low-end “flub”.
FAT SWITCH
–
In the same way the
TREBLE
knob (above) also controls
BRIGHT
, the MID operates as a “Fat”
switch, emphasizing midrange “body” by shifting the tonestack center frequency down.
BRIGHT SWITCH
–
Many amplifiers contain a “treble peaker,” included as a pull or toggle switch, or even
hard-wired. Every amp
TYPE
on the Axe-Fx II includes this control (even if the original mode does not). The
effect may be subtle or quite pronounced depending on the amp
TYPE.
This is also affected by the
BRIGHT CAP
setting (p.54). If the original amp had no bright circuit,
BRIGHT
is OFF by default but can still be turned on to
