The MXR Flanger/Doubler plug-in for UAD-2 hardware and Apollo interfaces is an exacting emulation of the stony '70s modulation processor that adds unique movement and depth to any source. From whooshing flange effects to subtle filter and delay textures, the MXR Flanger/Doubler plug-in is officially licensed by Dunlop Manufacturing.

By expertly emulating the original hardware's colorful, almost lo-fi-sounding "bucket-brigade" circuit, the MXR Flanger/Doubler plug-in offers everything from subtle thickening to whacked-out sci-fi effects, all with a unique texture and tone that has never been truly captured — until now.

• Add lush flanging and short delay textures to instruments and vocals with the legendary "bucket-brigade" processor
• Use the plug-in-only Sync button to lock the MXR Flanger/Doubler's filter sweep to your session's tempo
• Thicken guitars, drums, and synths with Doubler mode
• Bring movement, width, and complexity to stereo buses

History

Flanging originated as a tape effect where two tape machines are playing two identical and synchronized signals, and one is gradually delayed to create unique comb filtering effects. In the late 70's, MXR introduced the famed Flanger/Doubler unit which, unlike tape flanging, recreated this effect electronically via "bucket brigade" design.

Bucket-Brigade Technology

A bucket-brigade device (BBD) is an analog circuit that produces a delay by storing the signal in a series of capacitors, passing the stored signal from one capacitor to the next with each clock cycle. Because the signal is degraded with each pass, audio delay lines using BBDs tend to significantly color the signal.

The name is derived from human bucket brigades, whereby a line of many people remain stationary while passing many buckets from one person to the next. Bucket brigades were commonly used by firefighters to deliver water to a fire more efficiently than would be possible if each person were to carry a single bucket from the water source to the destination.

Operational Overview

Model 126

The MXR Model 126 Flanger/Doubler is an analog delay processor that uses "bucket-brigade" technology to create short signal delays. The delay time can be modulated manually, or automatically with a low frequency oscillator (LFO). The delayed signal can be mixed with itself in a feedback loop ("regenerated"), and its polarity can be inverted. The amount of processed signal relative to the original signal is adjustable.

All sonics and control behaviors are authentically modeled, including the inherent aliasing characteristics and dry signal path coloration.

Modes

Flanger

The flanging effect in MXR Flanger/Doubler is generated by using very short delay times whereby the delayed (wet) signal is not heard as separate from the original (dry) signal. When this delayed signal is combined with the dry signal, the comb filtering that is the essence of the flanging effect is generated. By modulating ("sweeping") the delay time, the response of the comb filtering is modified, and the characteristic "swoosh" is produced. Additional sonic options are possible by increasing the delayed signal feedback ("regeneration") to produce a deeper and more resonant effect, and/or reversing the polarity ("invert") to give the sound a more "hollow" character.

Doubler

When in Doubler mode, all controls have the exact same functionality as Flanger mode; the only difference is that the available delay times are longer in this mode. The delayed signal produces a very short echo, hence a "double" of the original signal is heard.

Software-Only Features

The MXR Flanger/Doubler plug-in has some features not included in the original hardware. The LFO rate can be synchronized to the tempo of the DAW session; the LFO can be reset; Stereo mode can apply processing to both sides of a stereo signal; and stereo output can be summed to mono.

Stereo Functionality

The original hardware is monophonic. To accommodate modern applications, the plug-in can be used in mono-in/stereo-out and stereo-in/stereo-out configurations. Two different stereo modes are available, and the stereo output can be summed to mono if desired. See for details.

In Use

The MXR Flanger/Doubler is well suited for sound-shaping, recording, and mixing, and even for adding some post-production flavor. Flanging is particularly popular as an individual effect on a wide range of musical sources — including guitar, bass, drums, keyboards, full source material, and more. Another common use for the MXR Flanger/Doubler is as a group effect, where effecting more than one signal is desired. Try applying the MXR Flanger/Doubler to drum buses or even the entire mix, most often for a brief period in the song, such as a break or bridge. In addition to Flanging, the Flanger/Doubler excels as a short-range delay/doubler.

MXR Flanger/Doubler Controls

Buttons

The buttons on MXR Flanger/Doubler are two-state switches. The buttons are ON when they are in the "DOWN" position. When ON/DOWN, they are gray with a darker "shadow." When OFF/UP, they are white.

Power

Power is the plug-in bypass control. Power is ON when the LED is red. When set to OFF, emulation processing is disabled, the LEDs are dimmed, and DSP usage is reduced (if DSP LoadLock is inactive).

Power is useful for comparing the processed settings to the original signal.

Effect

This button switches between Flanger and Doubler modes. It defines the range of signal delay available for the mode. The function of all the other controls is the same in both modes.

See Modes for additional details about the two effects.

Flanger

When in the "down" (gray) position, Flanger mode is active. This is the default setting.

Doubler

Doubler mode is active when the button is in the "up" (white) position.

Stereo Mode

This software-only switch modifies the processed signals at the outputs when used in a stereo-output configuration.

The control does not switch the processor between mono and stereo modes; both modes are true stereo (when configured for stereo output).

In both stereo modes (Single and Dual), stereo separation of the dry signals is maintained, and the stereo signal is not mixed to mono before processing is applied.

Note: This function is only available when the plug-in is used in a mono-in/stereo-out or stereo-in/stereo-out configuration. When used in a mono-in/mono-out configuration, the switch has no effect.

Single

When in the "up" (white) position, Single mode is active. This is the default setting.

In Single mode, the left and right signals are processed identically and the Sweep LFO for both channels are in phase.

Dual

When in the "down" (gray) position, Dual mode is active.

When Dual mode is enabled in a stereo-out configuration, the processing is applied to both the left and right channels. In this mode, the settings are the same for both processors, but a phase difference of 180° (antiphase) is applied between the Sweep LFO of the two channels. When Sweep Width is above 0% in Dual mode, this phase offset produces a swirling effect that pans back-and-forth.

Manual

This continuous control determines the delay time of the processor. The delay time is modulated by the Sweep LFO when the Width value is higher than 0%.

The available range of the control depends on the setting of the Effect button. In Flanger mode, the available delay time range is 4.9 milliseconds to 0.33 milliseconds. In Doubler mode, the available delay time range is 66 milliseconds to 18.5 milliseconds.

Sweep

The Sweep parameters (Width and Speed) control the LFO (Low Frequency Oscillator) that modulates the delay time of the processor.

Width

Sweep Width controls the amount of modulation applied to the delay time LFO. The available range is 0 - 100%.

At 0%, no modulation occurs and delay time is determined by the Manual setting. As Width is increased, the amount of modulation becomes "wider" (a broader sweep). At 100%, the delay time sweeps throughout its entire range, automatically creating the same sound as moving the Manual control repeatedly back and forth from minimum to maximum.

Speed

Sweep Speed controls the rate of modulation applied to the delay time LFO. The available range is 0.02 Hz to 15.96 Hz (this is the actual range of the original hardware; the knob text on the hardware panel doesn't match exactly). The current speed is indicated by the Sweep LEDs and also shown in the Rate Display.

The Sweep Speed can be synchronized to the tempo of the host application by engaging the Sync function.

Mix

This continuous control adjusts the blend between the original dry signal and the processed wet signal(s). The available range is 0 - 100%.

When set to minimum, only the dry signal is heard. When set to maximum, the signal is almost entirely wet, however a small amount of dry signal is present (like the original hardware).

When Mix is set to the minimum/dry position, the input signal is colored by the electronics of the unit (like the original hardware).

Regeneration

This is a feedback control for the delay processor. The available range is 0 - 100%.

When set above its minimum value, the output of the effect is routed back to its input. As the value increases, a more resonant signal is produced. Regeneration has a governor that prevents feedback "runaway" (overload) even when set to the maximum value of 100%.

Mono

This switch sums the stereo output of the dry and wet signals to mono when the plug-in used in a stereo-output configuration. This function is useful for creative purposes or checking phase relationships. The output is stereo when the switch is in the "up" (white) position, and mono when the switch in the "down" (gray) position.

Mono is only available when the plug-in is used in a mono-in/stereo-out or stereo-in/stereo-out configuration. When used in a mono-in/mono-out configuration, the switch is locked in the Mono position.

Note: See Stereo Mode for additional details about stereo output.

Invert

This switch inverts the polarity ("phase") of the processed signal. The wet signal polarity is normal when in the "up" (white) position, and inverted when in the "down" (gray) position.

When the processed signal is inverted and combined with the dry signal, the resultant comb filtering has a different timbre than when polarity is normal. This is particularly evident in Flanger mode, which often sounds more "hollow" when polarity is inverted.

Sync

The speed of the Sweep LFO can be synchronized to the tempo of the host application by engaging the Sync button. Tempo Sync is engaged when the button is in the "down" (gray) position and the LED above the button is illuminated.

See the "Tempo Sync" chapter in the UAD System Manual for detailed information about tempo synchronization.

Rate Display

The rate of the Sweep LFO is displayed here. When Sync is inactive, the LFO speed is displayed in Hertz. When Sync is active, the LFO speed is shown as a beat division (or multiplier). The Rate Display is unique to the plug-in; the original hardware does not have this feature.

Sweep LEDs

The Sweep LEDs, located above the Manual knob, perform two functions: LFO rate indication and LFO reset.

Rate

The Sweep LEDs illuminate in tandem with the current Sweep Speed, providing a visual indication of the LFO rate. The Width amount must be higher than 0% for the LEDs to blink. As Width increases, the blinking is more obvious.

The manner in which the LED response manifests depends on the state of the Manual, Width, and Speed controls; their quirky behavior is the same as the original hardware.

Reset

The LEDs provide a mechanism to reset the Sweep LFO so the sweep cycle can be consistently controlled. The LFO cycle is reset to begin sweeping "downwards" in pitch (negative sweep) by clicking either LED. This function, which is not available on the hardware unit, can be automated for mixing or bouncing.

Normally the Sweep LFO is "free running" but this behavior is not always desirable. For example, you may want playback to always sound exactly the same when bouncing or mixing. To accomplish this sonic consistency, the Sweep LFO must be started at a specific place in the LFO cycle by using the Reset function.

The MXR Model 126 Flanger/Doubler hardware unit