DAFX: Digital Audio Effects, Second Edition

4.3 Musical Distortion and Saturation Effects

4.3.1 Valve Simulation

Introduction

Valve or tube devices dominated electronic signal processing circuits during the first part of the last century and have experienced a revival in audio processing every decade since their introduction [Bar98, Ham73]. One of the most commonly used effects for electric guitars is the amplifier and especially the valve amplifier. The typical behavior of the amplifier and the connected loudspeaker cabinet have demonstrated their influence on the sound of rock music over the past decades. Besides the two most important guitars, namely the Fender Stratocaster and the Gibson Les Paul, several valve amplifiers have helped in creating exciting sounds from these classic guitars.

Valve microphones, preamplifiers and effect devices such as compressors, limiters and equalizers are also used for vocal recordings where the warm and subtle effect of valve compression is applied. A lot of vocalists prefer recording with valve condenser microphones because of their warm low end and smooth top end frequency response. Also the recording of acoustical instruments such as acoustic guitars, brass instruments and drums benefit from being processed with valve outboard devices. Valve processors also assist the mixing process for individual track enhancing and on the mix buses. The demand for valve outboard effects and classic mixing consoles used in combination with digital audio workstations has led back to entire valve technology ...