User Manual

STACK SECTION 17

Stack Section

The Stack section is the heart of the KPA. It represents the raw virtual guitar ampliﬁer as deﬁned by the

proﬁle. Every proﬁle is represented by the 3 modules that make the Stack section.

Ampliﬁer

The AMPLIFIER button calls up a list of parameters that allow you to change the character of the proﬁled

ampliﬁer in numerous ways using the soft knobs.

 Deﬁnition

The “Deﬁnition” parameter controls the characteristic ﬁngerprint of the preamp. The proﬁling process au-

tomatically sets “Deﬁnition” to a value that represents the reference amp. You could, for example, use it to

modernize the proﬁle of a vintage amp without having to use additional stomps. Alternatively, start with a

proﬁle of a modern tube amp, and use “Deﬁnition” to give it a more vintage sound when driven into distor-

tion. You can also use “Deﬁnition” to align the sound of your guitar to the sound of your amp, if required.

Don’t be afraid to keep experimenting until you get the balance that sounds best to you.

Vintage amps distort the lower harmonics in the guitar signal which gives them their bluesy sound. These

amps were originally designed to deliver a clean sound, so to achieve a creamy distortion, these amps

need to be driven by a typical transistor-based device like a treble booster.

Modern tube amps use a dierent approach, in which the higher overtones of the guitar strings are the

driving force for the distorted sound. The expensive boutique amps take this concept one step further, by

providing an extreme level of top-end frequencies and a large dynamic range. The distortion has a spar-

kling quality to it, and preserves every nuance of the strings and pickups. Together with the characteristics

of the actual speaker, the individual distortion behavior creates the ﬁngerprint that identiﬁes the ampliﬁer.