Our Own Additions; What Is Harmonic Distortion - Arturia DIST TUBE-CULTURE User Manual

1.1.1. Our Own Additions

We've expanded upon the Presence function of the Ultra Vulture with a switch that adds two
amounts of high-frequency boost. Where the Ultra had a fixed lowpass filter engaged with
a toggle switch, the input section Dist TUBE-CULTURE features highpass and lowpass filters
with variable cutoff frequencies as well as a stereo mode selector with mid-side options and
a one-knob compressor/expander/gate.
The output section also features highpass and lowpass filters, as well as the ability to "tilt"
the top of the EQ curve one way or the other relative to the high- and lowpass frequencies.
The result is a precise emulation of the Ultra Vulture that offers even more surgical control.
We have also refined the way that the Drive and Bias controls interact, making the Dist
TUBE-CULTURE plug-in very easy to dial in.

1.2. What Is Harmonic Distortion?

In technical terms, harmonic distortion is the addition of harmonics to a waveform by
misshaping (distorting) that waveform. Every sound is made up of a fundamental frequency
plus any number of harmonics, which are multiples of the fundamental.
Image Credit: Stefan Riepl via Wikimedia Commons
Compared to solid-state electronics, vacuum tubes (valves) distort the waveform more
gradually as they're pushed to their operational limits. (This pushing is done via input
gain, and in the case of Dist TUBE-CULTURE, the Drive and Bias knobs.) Depending on the
settings, this favors either even-numbered or odd-numbered harmonics, which decrease in
amplitude as their frequencies increase.
Musically speaking, vacuum tubes do this in a way that's pleasing to the human ear.
Musicians and audio manufacturers describe this phenomenon with words like "warm,"
"fat," and "round." Solid-state electronics can produce desirable distortion — and are used to
do this in most guitar distortion pedals — but there is far less room to play between a clean
sound and all-out heavy metal fuzz.
Simply put, there's analog and then there's tube analog!
4 Arturia - User Manual Dist TUBE-CULTURE - Welcome to Dist TUBE-CULTURE