Tremolo/Panner block

Available on which products

• Axe-Fx III, FM9, FM3: 2 blocks
• Axe-Fx II, FX8: 2 blocks
• AX8: 1 block

Channels or X/Y

• Axe-Fx III, FM9, FM3: 4 channels
• Axe-Fx II Mk I, II: no
• Axe-Fx II XL, XL+, AX8, FX8: X/Y

Tremolo/Panner types

VCA Trem

Previously known as Tremolo, Regular tremolo is based on a voltage-controlled amplifier topology.

Panner 

Stereo panning between left and right.

Bias Trem 

Tube simulation algorithm that replicates the bias tremolo in vintage tube amps. As the FM3 does not support Bias Tremolo in the Amp block, use this instead.

Harmonic Trem 

 Recreates the famous sound of the tremolo circuit in the old Brownface amplifiers. This effect splits the spectrum and applies modulation to the two frequency bands. The Crossover Slope parameter selects the filter order for the crossover. The original circuit used a 6 dB/octave crossover. Higher slopes can give a more intense effect. The crossover frequency can be changed with the Crossover Frequency parameter. Note: unlike most implementations, the Axe-Fx III version is full stereo and can be used before or after the Amp block without losing stereo separation. Additionally, the effect supports the LFO phase for the left/right which can be used to achieve unique sounds. Furthermore, the effect supports LFO types other than Sine for even more unique sound.

Optical Trem 1 

Based on optical pedal tremolos where depth controls the intensity of the LED.

Optical Trem 2 

Based on optical pedal tremolos where depth controls a mixer pot. This type has more throb than Optical Trem 1.

Neon Trem 

Based on the optical tremolo in classic Blackface amps which used a neon bulb to illuminate the LDR.

The Bias and Harmonic types use nonlinear processing techniques and, as such, may add distortion to the audio signal, just as their tube-based counterparts would.

The Tremolos were improved in firmware 23. An LFO waveform monitor has been added for appropriate types.

For more information see:

• The forum's discussion: The Flint Tremolo Done Right
• Strymon's white paper: Amplifier Tremolo TechnologyPaper

FRACTAL AUDIO QUOTES

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[1] I like the Harmonic Trem on clean and light crunch before an amp. It takes on a slight phaser vibe. Another cool thing to try is to put it near the end of the chain and set the LFO Phase to 180. Funky stereo tremolo.

Tremolo/Panner block position on the grid

If the Tremolo block is placed before the Amp block and there's a lot of amp gain, the tremolo effect will be less noticeable because of the compression of the signal. Adjust the waveform or the Duty parameter to emphasize the pulse. Or move the Tremolo block to a position after the Amp block.

The Panner pans the signal left and right, just like a ping pong delay. This requires the signal not being summed to mono after the Tremolo/Panner block.

Tremolo/Panner block diagram

Parameters

LFO Phase (mono/stereo)

Set LFO Phase to 0 for mono output, and to any other value for stereo output.

Depth

There's no Mix parameter In the Tremolo block. Use Depth instead, because a tremolo's modulation is volume-based.

FRACTAL AUDIO QUOTES

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[2] Mix makes no sense in a tremolo as it is the same as reducing the depth.

Duty

Use this parameter to change the character of the tremolo peaks from a regular tremolo to electronic blobs.

Tips, tricks and troubleshooting

Factory presets

The Tremolo/Panner block is showcased in many factory presets. Search the Factory presets page for tremolo or panner or panned.

Trigger the tremolo

To trigger the Tremolo when engaging the block: use the Start Phase parameter.

To trigger the Tremolo when hitting the strings (synchronize the Tremolo to your playing): turn up the Trigger Threshold parameter. When the Tremolo is triggered, it will start and the LFO phase will start at the Start Phase value. Turn Trigger Threshold all the way down to defeat the trigger.

In firmware without the Trigger Threshold parameter, set Rate to LFO1 SYNC, sync LFO1 to a Tempo, and attach the LFO to the Envelope follower.

FRACTAL AUDIO QUOTES

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[3] You can adjust where in the waveform it starts with the Start Phase control.

Bias Tremolo in Amp block

The Amp block in the Axe-Fx II and III and FM9 provides its own Bias Tremolo.

Widen the panning

Make the Panner effect appear fuller and wider, by adding the Enhancer block.

Alternative for Panner

As an alternative to using the Panner block, attach an LFO to a panning parameter in a block.

Ring Modulator as a tremolo

You can configure the Ring Modulator block to operate as a tremolo, by turning down Frequency all the way.

Tremolo as an On/Off switch

Set the Tremolo block's LFO to Square with Depth at 100%.

Shuffle tremolo

See the forum's Shuffle tremolo tempo? discussion.

Vox Percussion Tremolo

To recreate the Percussion Tremolo effect on old Vox guitars, set LFO Type to Saw Down.

Syncing to the metronome

Forum thread: Sync the tremolo to the metronome