KORG PA4X 76 - Manual (Page 605)

Effect parameters |601
aMP (amplifier)
Pa4X includes accurate guitar and bass amplifier and cabinet modeling.
Some of the effects combine an amplifier and a cabinet model.
Modelling amplifiers
Pa4X comes with a wide selection of the best amps, that offer the widest
possible array of great tones. The operating mode of the preamp and power
amp, the response of the tone controls, and their placement within the cir-
cuit will change depending on the type of amp you select, precisely replicat-
ing the exact gain and tonal character of the original amp. The all-impor-
tant power amp stage (class A or AB) and negative-feedback circuit (or lack
thereof) are also carefully simulated.
The volume controls
Two main controls affect the volume (or gain) and at the same time the tone
of the amp: Drive Gain (controlling the preamp gain and the amount of pre-
amp distortion) and Volume (controlling the preamp output level). Each con-
trol has its own specific job, and the sound of a particular amp model can
vary over a very wide range just depending on the settings of these controls.
In addition, the
Cabinet Trim control (a power attenuator) is placed between
the output of your amp and the input of your speaker cabinet. At the end of
the signal path, the
Wet/Dry parameter in the FX Edit page, and the Master
knob in the Mixer/Tuning > FX Send page, control the level of the final mix
and allows you to balance all your presets to each other.
We have made the relationship between preamp and power amp work in the
same way as in the original amps. Therefore, to obtain truly authentic tones,
please use the Pre/Drive Gain parameter to control the preamp distortion,
and the Volume parameter to control the distinctive distortion and warmth
of the power amp stage.
Be advised that setting the Drive Gain too high will result in heavy distortion,
and is not recommended.
Tube talk
‘Tubes’ is the name adopted in the USA, while ‘valves’ is the British equiva-
lent. As all the amps we’ve modelled come from one of the two countries just
mentioned, we will use the corresponding term in the following descriptions.
Also, please note that an ECC83 preamp valve is the British version of a
12AX7 preamp tube used in the USA.