Yesterday we discussed Fender's first tremolo effect, as found in the company's 1955 Tremolux amplifier. A variation of this appeared a few years later, when the Tremolux was modified to run on power tubes with fixed bias. This circuit used the oscillator pulses to fight against the bias supply. This particular tremolo was used in the brown Deluxe and Vibrolux amps, along with the brown Vibroverb of 1963. It was this circuit that was the inspiration for Fender's revival of the tremolo effect in its amps beginning in 1990. As it works directly on the power tubes, this particular tremolo can be very deep and intense.