One of the earliest guitar effects built into early guitar amps was the Tremolo and Vibrato effect.
Although the terms are used interchangeably, technically Tremolo is an up and down pattern of
volume and Vibrato is an up and down patter of pitch. These effects occur almost naturally in the
singing voice and are taught as a natural part of playing violins, violas, cellos and saxophones.
Rotating Speaker Tremolo and Vibrato
For electronic organs, the tremolo/vibrato effect was
often generated by the use of a rotating speaker called a Leslie. The rotations cause both a
tremolo and vibrato because the motion of the speaker had the effect of altering the volume depend
on direction and altering the pitch by means of the Doppler effect.
Tremolo and Vibrato in 1960s Amps
Aside from the Leslie, the original effects built into
amps were not very subtle. In the 1960s guitar amps typically had simple tremolo and/or vibrato
effects that produced a very noticeable loud soft pattern. Most of these amps could turn the effect
on and off with a footswitch, change the intensity of the effect with a knob, and occasionally
speed or slow down the effect. Today’s Tremolo/Vibrato Pedal Effects can do quite a bit more and
can be equally noticeable or much more subtle as needed.
Top Choices in Tremolo, Vibrato, and Leslie Speaker effects
For example, look at what these
pedals do:
The
TC Electronic Shaker
Vibrato
includes a classic true pitch vibrato capable of adding a Leslie speaker effect to
guitars, voices, and whatever. You can control the speed and depth of the effect and its timing
(how long it takes to start after you engage the pedal). It has a USB connection that lets you
download custom tunings made by and ever expanding roster of fine guitarists. You can also use this
pedal to get whammy bar effects. Being a product of TC Electronic, this pedal has some of the
finest circuit design available and of course true-bypass.
The
DigiTech
HardWire TR-7 Tremolo Rotary Vibrato Pedal
is one of the most versatile pedals in this category. It can produce seven effect types
including Rotary (Leslie Speaker) effect and classic Fender and Vox vibrato and tremolo effects.
You can have interacting dual synchronized tremolos, variable waveform tremolo, and panning
vibrato. The Digitech Hardwire Tremolo is a true stereo unit with stereo inputs and outputs and has
true bypass circuitry.
The
Boss
RT20 Twin Rotary Guitar and Keyboard Pedal
produces one of the most authentic Rotary Speaker simulations. Using Roland’s proprietary
COSM sound modeling technology reproduces all details of the classic rotary speaker design
including adjustable rise time, horn speaker speed, and bass speaker speed. You get overdrive
effects, pulsating effects, and even a classic Univibe effect.
Many players just want to keep it simple with the
Boss TR2 Tremolo
Effect Pedal. You can control waveform, rate, and depth of this classic tremolo
effect. The sound is just what you would get from the built in tremolo on a vintage guitar amp from
the 1960s.
The
Pigtronix
Tremvelope Tremolo Effect Pedal
is an example of the LFO controlled Auto Wah. With its envelope follower switched off the
audio path is modulated by a Low Frequency Oscillator with speed, depth, and waveform controls, for
a versatile Tremolo effect with stereo panning. With the Envelope control switched on the tremolo
is controlled by the dynamics of your guitar playing. The sound is akin to what you get playing
through a rotating Leslie speaker, but with continuing changes in rate and depth.
