Modulation-related effects
Rotary Speaker
Rotary speaker effects are created by accomplished by amplifying a sound through spinning speakers or horns and/or by placing a rotating baffle in front of a speaker. This creates a doppler effect, and depend on the speed of the rotation, translates into phasing, flanging, chorus, vibrato, or even tremolo. In addition to the basic rotating speaker sound, other effects created with these cabinets included changing the speed, turning the motor on and off (causing a pitch “wobble” effect), and using two rotating speakers at once, a rich, chorusing sound nicknamed the “voice of God” by Leslie fans.
Leslie speakers: The wooden cabinet has rotating baffle near the bass speaker, and a horn speaker that rotates like a siren. Originally designed for Hammond organs, they are also used by some Guitarists. Some Leslie enthusiasts claim that that no electronic effects or software modelling devices can duplicate the complex doppler effects that the speaker creates.
Fender Vibratone: This is a simplified version of Leslie Speaker, containing only a 10″ speaker with a rotating baffle.
Rotary Speaker Simulator
Electronic Leslie-style effects duplicate the sound of a rotating speaker, but they offer different simulations of the effects of the rotation speed, volume, and pitch modulation. Some Leslie-style pedals can provide two or more modulation effects at the same time. Despite the numerous different analog devices, it is very rare for them to be able to duplicate all aspect of a Leslie speaker. Thus, Rotary Speaker Simulator are always going to be digital, utilizing modelling algorithms to model the relations between the rotating horns and bass baffle, and how the sound bounce around the cabinet. As Leslie also have a tube amplifier, most of these pedals have an overdrive circuit. Some of these pedals can even accept an 11-pin Hammond organ keyboard input.
Boss RT-20 Rotary Ensemble Pedal: This is one of the few pedals that is capable of modelling all aspect of a Lesile Speaker.
Line 6 Rotomachine: Also a modelling pedal, it is available in a compact pedal size.
DLS Roto-Sim: Hybrid of analog with DSP modelling.
Vibrato
A Vibe or vibrato pedal reproduces the sound of a rotating speaker by synchronizing volume oscillation, frequency-specific volume oscillation, vibrato (pitch wavering), phase shifting, and chorusing in relation to a non-rotating speaker. The modulation speed can be ramped up or down, with separate speeds for the bass and treble frequencies, to simulate the sound of a rotating bass speaker and a rotating horn. This effect is simultaneously a volume-oriented effect, an equalization-oriented effect, and a time-based effect. Furthermore, this effect is typically related to chorus. Some vibe pedals also include an overdrive effect, which allows the performer to add “tube”-style distortion. Some Vibe pedals include:
BBE Soul Vibe
Voodoo Lab Microvibe
Some vibe-chorus pedals include
Dunlop Univibe
Dunlop Rotovibe
BBE Mind Bender
Phase Shifter
Main article: Phase shifter
A phase shifter creates a complex frequency response containing many regularly-spaced “notches” in an incoming signal by combining it with a copy of itself out of phase, and shifting the phase relationship cyclically. The phasing effect creates a “whooshing” sound that is reminiscent of the sound of a flying jet. This effect dominates the sound in the song Star Guitar by Chemical Brothers. The song was not played with any Guitars but one can hear the phasing effect. The instrument being phased was actually a synthesizer. Some electronic “rotating speaker simulators” are actually phase shifters. Phase shifters were popular in the 1970s, particularly used with electric piano and funk bass Guitar. The number of stages in a phase shifter is the number of moving dips in the frequency response curve. From a sonic perspective, this effect is equalization-oriented. However, it may be derived through moderate time-based processing. Some phaser pedals include:
MXR M-101 Phase 90
Boss PH-3 Phase Shifter
Electro-Harmonix Small Stone
Moog MF-103 12 Stage Phaser
DigiTech Hyper Phase
Flanger
Main article: Flanging
A flanger simulates the sound effect originally created by momentarily slowing the tape during recording by holding something against the flange, or edge of the tape reel, and then allowing it to speed up again. This effect was used to simulate passing into “warp speed,” in scifi films, and also in psychedelic rock music of the 1960s. Flanging has a sound similar to an auto-wah, but weaker, yet is closely related to the production of chorus.
The first pedal-operated flanger designed for use as a Guitar effect was designed by Jim Gamble of Tycobrahe Sound Company in Hermosa Beach, CA, during the mid 1970s. Last made in 1977, the existing “Pedalflangers” appear occasionally on eBay and sell for several hundred dollars. A modern “clone” of the Tycobrahe Pedalflanger is sold by Chicago Iron.Famous users of this Flanger effect include Randy Rhoads and Eddie Van Halen, coincidentally they both used the MXR M-117R flanger and Eddie Van Halen even has his own signature model now.
Examples:
Boss BF-3 Stereo Flanger
Line 6 Liqua Flange
MXR M-117R Flanger
Danelectro FAB Flange
Electro Harmonix Deluxe Electric Mistress
DigiTech Turbo Flange
Chorus
An electronic chorus effect splits a Guitar signal in two, modulating the second signal’s pitch and mixing back in with the “dry” original signal. The effect sounds like several Guitarists playing the same thing at the same time, resulting in a wide, shimmering or swelling sound. Some common chorus pedals are:
Boss CH-1 Super Chorus
Electro-Harmonix Small Clone
Ibanez CF-7 Chorus/Flanger
Line 6 Space Chorus
MXR M-134 Stereo Chorus
Detune effect on Digitech Whammy
TC Electronic Stereo Chorus /Flanger /Pitch Modulator
Tags: guitar accessories, Guitar Amplifiers, Guitar Effects Pedals, Guitar wireless systems
