The History of Tremolo and The beginnings of Vibrato....
Simply put, Tremolo is a cyclic change in volume. Tremolo, a.k.a. amplitude modulation, is a very pleasing effect and probably the first built into an amp, starting in the late 1940's with Danelectro, Gibson, and Premier. In 1955 Fender introduced the Tremolux (model 5E9). This was Fender's first amp with Tremolo. Meanwhile, in nearby Inglewood, Magna Electronics known for student lap-steel/amp combos was manufacturing real professional amps that incorporated unique designs and revolutionary new features such as Stereo Vibrato.
So in 1956 Fender introduced the Vibrolux. The Vibrolux supposedly had Vibrato (pitch modulation), but in reality this was just another variation on the Tremolo already found in the Tremolux. In fact, NO Fender amp has EVER had true pitch-bending vibrato, regardless of catalog hype to the contrary.
Try this Experiment at Home
Plug your guitar into your amp and power it up. Now strum a chord and turn the volume control up and down rhythmically and repeatedly. You will hear Tremolo. This is what Fender and many others called Vibrato.
Now try this
Fret one of your guitar strings and rhythmically rock your finger back and forth in a sideways motion stretching the string slightly. Notice the pitch is changing, This is Real Vibrato.
Don L. Bonham's Patented Vibrato Circuits
Sometime in the 1950's, Magna Electronics Inc. started to manufacture the now famous Magnatone guitar amps. They were the first and only guitar amps with real Vibrato. Vibrato a.k.a. frequency modulation, is a cyclic pitch change. Magnatone amps had great tone and features, but were under powered, too heavy, and exspensive compared to the market leaders, Fender and Gibson. These other amp manufacturers probably knew this and were quick to change their amp labeling and advertising to indicate that their amps also had Vibrato. Even the Vibrosonic, made by Fender in 1959, had only a complex Tremolo circuit.
On June 13, 1961, Don L. Bonham was granted a U.S.Patent # 2,988,706 for his Vibrato circuits. By now the Estey Organ Company had bought Magna Electronics and redesigned many of the amps. Magnatone amps were still the only ones with electronic Vibrato but by 1965 Fender and the others had the bigger share of the Market. Well why not, their guitar amps supposedly had vibrato and were less exspensive. To this day the only guitar amp that effectively incorporated Real Vibrato, was the Magnatone line of Amps.
There are other acoustic and electronic ways to make Vibrato i.e. Leslie's Doppler effect and Hammond's distributor RC Network, but none is as magical as the "Golden" Voice of Magnatone. This is what the Vibroman 2.0 Stereo Tube Effects is designed from, using the very same Varistor arrangement as the Magnatone Model 280.
Written by Greg Zaccaria, Owner Zack Engineering © 1996